Vortex 6000 Laser Controller
Contents
1. lt 3 4004 gt 1 438 0 125 1 375 oO oO N uu e J i O 2 625 gt Assembly Detail of the Laser es Head Bracket 1 th N 5 9 th o 6 5 t 5 N N T OO rrt i gt 1 000 Weight of Laser Head and mounting bracket 2 Ibs 1 kg 60 Appendix I Physical Specifications New Focus y Aen st Bearnan StableWave Laser Head and Mounting Bracket A gt j 3 400 id X 3 2x te 2 1 000 00 A Weight of Laser Head and mounting bracket 2 lbs 1 kg 7000 6000 Series Appendix I Physical Specifications 61 62 Appendix I Physical Specifications mA M Division of Bookham Appendix II RS 232 Connector Wiring RS 232 9 Pin D Connector The RS 232 connector on the back of the StableWave Vortex controller is a standard female 9 pin D connector The laser controller transmits data on pin 2 and receives data on pin 3 see below If you have trouble communicating with the laser over the RS 232 port you may need to use a null modem adapter or cable Figure 10 6 7 8 9 5 inti RS 232 Female in ame escription 9 Pin D Connector 1 Not Connected _ _ _2. Set the operating current or power Press the Display button until the current 0 0 mA for constant current mode or the power 0 0 for constant power mode is displayed If the Set button is not already lit press it to enable the adjustment knob Turn the knob to set the current or power To prevent damage to the laser diode the factory has limited the maximum current to the operating current listed on the Acceptance Test Data Sheet Activate the laser Push the Power button to activate the laser power The button will flash for 5 seconds before current flows through the diode Laser light should now be emitting from the aperture Laser radiation emitted from this unit may be harmful Avoid direct exposure to the beam Turn the laser off To minimize the risk of power surges damaging the laser diode push the Power button to turn off the laser when it is not in use the LED on the button will turn off and before shutting down the system Turn the keyswitch off position 0 to shut down the entire system O New Focus a y Aen s earnan General Operation Overview What s Inside 7000 6000 Series The StableWave Vortex is a robust narrow linewidth laser source The system consists of a laser controller a laser head and a laser cable Each Vortex laser head contains head specific information so that it can be used with any StableWave Vortex laser controller This modular design allows you to swit
3. Understanding the Command Types CONVENHONS cvdedadadegucduosmadesetaeason sns Command 5 esee senee Command Definitions yes cednceencecsene sents Principles of Operation 0 7 Changing the AC Voltage Selection Customer Service Service dd tt ana ER aden edanereelouer sehen an4 0 Appendix I Physical Specifications orccaanecacsnavenquaseseronneann4 Vortex Laser Head and Mounting Bracket StableWave Laser Head and Mounting Bracket Appendix II RS 232 Connector Wiring RS 232 9 Pin 12 6026010 Index K M 31 31 ssa 2L san 22 TE 3 TRS 36 38 51 saaal re 55 57 reg 7 59 0 60 61 63 v4 63 65 Division of Bookham User Safety Introduction Your safe and effective use of this product is of utmost importance to us at New Focus Please read the following laser safety information before attempting to operate the laser Laser Safety The laser radiation emitted from this unit may be harmful Always follow these precautions e Avoid direct exposure to the beam e Avoid looking at the beam directly Be aware of and follow the warnings on the safety labels examples are shown on page 8 e Tocompletely shut off power to the unit turn off the keyswitch The Power button on the front of the controller controls power to the laser diode even when the power to the diode is off power is still being supplied to
4. Division of Bookham and slogans are trademarks or registered trademarks of Bookham Inc in the U S A and other countries Littelfuse and Slo Blo are registered trademarks of Littelfuse Inc Document Number 600013 Rev K Contents User Safety 5 Introduction 23 ccoe capitan Ane ceeandnandsaeaet vans 5 L ser Safety e roie e dain eastannsigasanssuceede 5 Using the Safety Interlock 43 ges cack dane se ouedes 9 Getting Started 1 0000 eee 11 Unpacking the Systems iavily aes etaeedaxeetaces 11 tsi acsesaccdinemanenem ewes 11 Starting the StableWave Vortex for the First Time 13 General Operation 15 MV CIVIC Wi ssi sides ct hast b s arn a tee EAA OR wri 15 What s Inside wuss co see vetdesia eree 15 Mounting the 607 16 Using the Front Panel Controls 17 Turning on the Power 22s ne nscenuks vacates 19 Selecting an Operating 066 4 19 Displaying and Setting the Laser Parameters 21 Restoring Local Front Panel Control 22 Modulating the 1 4807 22 Reading an Input Signal sa cavecssctcuusesabasneces 25 Constant Power Mode 27 7 Preparing to Use Constant Power Mode 7 Operating in Constant Power Mode 28 7000 6000 Series Contents 3 4 Contents Computer Control Introducti f 6 i cuaduesaduateans vee ir aiani Using the IEEE 488 10101666 Using the RS 232 Interface sssstc soedeeewenews Restoring Local Front Panel Control
5. Syntax SOURCe VOLTage PIEZO Vortex Actions Queries the piezo voltage setpoint Response xV range 0 0 to 117 5 Sense Piezo Voltage Syntax SENSe VOLTage PIEZo Vortex Actions Returns the piezo voltage reading Response range 0 0 to 117 5 Computer Control 49 50 Computer Control Set Frequency Modulation Gain Syntax CONF GAIN lt gain gt Vortex Actions Sets the frequency modulation gain setting default setting is high Argument HIGH or LOW Gain factor High 25 Low 1 Example Set the FM Gain to low 1x CONF GAIN LOW Query Frequency Modulation Gain Syntax CONF GAIN Vortex Actions Queries the frequency modulation gain setting default setting is high Response HIGH or LOW Gain factor High 25 Low 1 M O New Focus a Division of Bookham Principles of Operation Overview Traditional diode laser technology provides high reliability high electrical efficiency and a wide range of available wavelengths in a compact package By using an external cavity built around a diode laser the StableWave Vortex enhances the performance of off the shelf diode lasers guaranteeing single mode operation with narrow linewidth and precise wavelength tuning The short term linewidth of the StableWave Vortex laser is lt 500 kHz o
6. results from two competing wavelength selection constraints the mirror grating angle and the laser cavity length The laser cavity length L defines a discrete set of possible wavelengths or modes Ay that can lase given by the equation L NAy 2 N integer The grating equation insists that 4 A sin 6 sin where A refers to the groove spacing of the grating while 6 and 0 refer to the incident and diffracted angles of the laser beam Rotation of the end mirror causes parameters in both equations to change An appropriately selected point of rotation synchronizes the two such that the cavity length remains the same number of half wavelengths long as the mirror is being rotated Thus mode hop free tuning is achieved When this condition is not met the lasing wavelength will periodically hop from one mode to the next e g from N to N 1 as the laser is tuned The mechanical design of the Vortex provides truly mode hop free tuning The StableWave Vortex controller provides current voltage and temperature controls to the laser head as well as manual and computer controlled input output interfaces The low noise current supply drives the diode in the laser head controlling the output power The voltage controller drives the piezo in the laser head controlling the lasing wavelength Finally the temperature control regulates the laser cavity temperature providing a stable output wavelength The laser wavelength is also affected
7. Syntax SYSTem INFormation HMANufacture Vortex Actions Returns the date of laser head manufacture Response mm dd yy Month Day Year O New Focus a y Aen s Beannan 7000 6000 Series Query Laser Head Operating Hours Syntax SYSTem INFormation DHOurs Vortex Actions Returns the laser head operating time Response xxxxxHrs range 0 to 65536 7 5 years Query Laser Head Wavelength Syntax SYSTem INFormation HWAVelength Vortex Actions Returns the nominal head wavelength Response nm System Commands Set System Operating Mode Syntax CONF MODe lt mode gt Vortex Actions Sets the system to constant current or constant power mode Argument CURRent or POWer Example Set the laser to operate in constant current mode CONF MOD CURR Query System Operating Mode Syntax CONF MODe Vortex Actions Queries the system operating mode Response CURRENT or POWER Example Determine whether the laser is operating in con stant current or constant power mode CONF MOD gt POWER the laser is in constant power mode Computer Control 5 Turn Laser On Off Command Syntax OUTPut lt value gt Vortex Actions Turns the laser head on or off Argument 0 for laser current off and 1
8. for laser current on Example Turn off power to the laser OUTP 0 Query Laser Power Syntax OUTPut Vortex Actions Reads laser current status Response 0 for laser current off and 1 for laser current on Example Determine if the laser current is on or off OUTP the laser is turned on Sense Auxiliary Voltage Syntax SENSe 01 7886 AUXiliary Vortex Actions Returns the auxiliary input voltage reading Response X xxxV range 0 0 to 4 000 46 Computer Control O New Focus A y 7000 6000 Series Current Diode Commands Set Diode Current Syntax SOURce CURRent lt current gt Vortex Actions Sets the diode current setpoint when in constant cur rent mode Argument X X range 0 0 to 160 0 units are in mA Example Set the diode current to 88 8 mA SOUR CURR 88 8 Query Diode Current Setpoint Syntax SOURce CURRent Vortex Actions Queries the diode current setpoint when in constant current mode Response x xmA range 0 0 to 160 0 Example Read the setpoint for the diode current SOUR CURR gt 99 3mA Sense Diode Current Syntax SENSe CURRent Vortex Actions Returns the laser diode current reading Response x xmA range 0 0 to 180 0 Computer Control 47 48 Computer Control Sense L
9. Register Syntax ESE lt value gt Vortex Actions Sets the specified bits of the Event Status Enable Register When a corresponding bit in the Standard Event Status Register becomes true enables the Event Summary Bit ESB in the Status Byte Argument An integer in the range 0 to 255 corresponding to the combined weight of the bits you want to set Standard Event Status Enable Register Bit Weight Description 7 128 Enable ESB in case of power on or restart 6 64 not used 5 32 IEEE enable ESB in case of a command parse error RS 232 not used 4 16 IEEE enable ESB in case of system not available or invalid data error RS 232 not used 3 8 not used 2 4 Enable ESB in case of query error 1 2 not used 0 1 not used Example Enable the ESB if the system is restarted ESE 128 O New Focus a y as 7000 6000 Series Query Standard Event Status Enable Register Query Syntax ESE Vortex Actions Queries the Event Status Enable Register Response An integer in the range 0 to 255 corresponding to the combined weight of the bits that are set See the Set Standard Event Status Enable Register command definition on page 40 for a description of the bits and their weights Example Check which bits of the register are enabled ESE gt 164 164 128 32 4 the ESB bit will be enabled in
10. also use the current modulation inputs for fine frequency fine wavelength control because the frequency changes with the current Division of Bookham 22 General Operation pron Focus 7000 6000 Series Modulating the Frequency You can modulate the laser frequency wavelength by using an externally generated analog signal to modulate the voltage of the piezoelectric actuator the piezo directly controls the laser frequency To modulate the frequency connect the line for the input signal to the Frequency Modulation connector on the back of the StableWave Vortex controller Make sure the signal conforms to the following specifications Frequency Modulation Input Guidelines Connector Type BNC Max Voltage 4 5 V Input Frequency Range DC 3 5 kHz Impedance 50 The frequency modulation signal is added to the set DC level for the piezo set either through the front panel or by computer control Increasing the voltage increases the laser frequency decreases the wavelength decreasing the voltage decreases the frequency The total piezo voltage the DC level plus the frequency modulation signal is limited to a range of 0 to 117 5 V The tuning range is laser dependent see the Acceptance Test Data Sheet that accompanied your laser head for the tuning range specification For fine frequency control you can modulate the current since changes in current will affect the frequency See Modulating the Cu
11. by the current through the diode Changing the diode current affects the refractive index of the diode lasers and therefore the laser cavity length The magnitude of the effect is diode dependent but is typically 25 150 MHz mA 52 Principles of Operation New Focus y Aen s earnan 7000 6000 Series References T Day F Luecke and M Brownell Continuously tunable diode lasers Lasers and Optronics pages 15 17 June 1993 K C Harvey and C J Myatt External cavity diode laser using a grazing incidence diffraction grating Optics Letters vol 16 pages 910 912 1991 M G Littman and H J Metcalf Spectrally narrow pulsed dye laser without beam expander Applied Optics vol 17 pages 2224 2227 1978 M G Littman Single mode operation of grazing incidence pulsed dye laser Optics Letters vol 3 pages 138 140 1978 M G Littman Single mode pulsed tunable dye laser Applied Optics vol 23 pages 4465 4468 4 K Liu and M G Littman Novel geometry for single mode scanning of tunable lasers Optics Letters vol 6 pages 117 118 1981 Principles of Operation 53 54 Principles of Operation g M Division of Bookham Changing the AC Voltage Selection The StableWave Vortex Controller can operate at 100 120 220 or 240 V AC at AC frequencies of 47 63 Hz The unit is configured at the factory for the standard AC voltage of the purchaser s country To ch
12. each command The following conventions are used in both the Command Summary and the Command Definitions sections The part of the command shown in uppercase represents the short form of the command The commands are case insensitive Computer Control 33 If the syntax shown is SOURce CURRent then the StableWave Vortex will accept any of the following SOUR CURR sour curr or sour current The Vortex will not accept commands such as S OURC CURR or sour curre Values to be input are indicated by angle brackets lt gt and are separated from the command either by a space or by a colon as shown in the command syntax Common IEEE 488 commands all begin with an asterisk character the device specific commands all begin with a colon These characters are not optional StableWave Vortex responses are sent differently depending on the interface you are using IEEE 488 responses are written into the output buffer a first in first out FIFO buffer with a capacity for 5 outgoing messages You will need to send a separate command to read the response from the buffer RS 232 responses are sent immediately and can be processed or ignored Programming for the StableWave Vortex When programming for the StableWave Vortex keep the following rules in mind 34 Computer Control A command is not parsed until a new line character is received RS 232 o
13. power Only power and laser frequency piezo voltage can be varied in constant power mode The laser power displayed in this mode is given in terms of a percentage of maximum auxiliary input signal Constant power mode requires use of an external beamsplitter and a photodetector to measure the laser power and provide an electrical signal for the internal feedback circuit See the Constant Power Mode chapter beginning on page 27 for details on setting up and using the Vortex in constant power mode Setting the Operating Mode The Constant Current and Constant Power LEDs on the front panel see Figure 5 on page 17 indicate which mode is active To change the mode 1 Make sure the power to the laser head is off If the LED in the Power button is lit then the laser head is on press the Power button to turn off the laser power 2 Press the Mode button to switch modes The mode indicator on the front panel will change to show the newly selected mode 3 Press the Power button to re activate the laser head O New Focus a y Aen s Beannan In order to use the StableWave Vortex in constant power mode you will need to use a beamsplitter and a photodetector see Constant Power Mode on page 27 for details Displaying and Setting the Laser Parameters Use the front panel to display either the set value or the actual operating value of the laser parameter you want current laser power piezo voltage which contro
14. the laser head for temperature control e Do not open the laser head or controller Diode laser power at the wavelengths shown in the following table could be accessible inside the laser head There are no user serviceable parts inside the laser head or controller Unauthorized opening of the head or controller will void the warranty and may result in misalignment of the laser cavity and or irreparable damage to the internal components The following tables contain a list of wavelength ranges and maximum internal powers accessible inside the different model laser heads Look 7000 6000 Series User Safety 5 6 User Safety at the label on top of your laser head for its model number and its specific wavelength Vortex Series Lasers Model Wavelength Range Max Power 6005 600 645 nm 15 mW 6009 630 710 nm 30 mW 6013 710 800 nm 70 mW 6017 760 905 nm 100 mW 6021 830 1180 nm 100 mW 6025 1100 1480 nm 30 mW 6027 1350 1710 nm 50 mW 6029 1380 1710 nm 50 mW 6031 1550 1900 nm 25 mW 6033 1610 2400 nm 100 mW O New Focus a y Aen e Beannan StableWave Series Lasers Model Wavelength Range Max Power TLB 7004 632 5 640 nm 10 mW TLB 7005 652 660 nm 6 mW TLB 7008 668 678 nm 6 mW TLB 7009 680 690 nm 6 mW TLB 7013 TLB 7013 H 765 781 nm 150 mW TLB 7014 794 806 nm 25 mW TLB 7015 815 825 nm 25 mW TLB 7017 838 853 nm 150 mW TLB 7018 89
15. to operate the instrument refer to the General Operation chapter beginning on page 15 Unpacking the System Carefully unpack the StableWave Vortex laser system Compare the contents against the packing slip and inspect them for any signs of damage If parts are missing or you notice any signs of damage such as dented or scratched covers or broken knobs please contact New Focus immediately For orders with multiple heads up to 3 heads may be shipped in the same container Save the shipping container and packing material for future shipping needs Check that the power module on the back of the controller is set for the proper AC line voltage see page 55 for information on checking and changing the voltage Setting Up the Laser 7000 6000 Series 1 Mount the laser head The laser head is shipped with a mounting bracket already attached This bracket also serves as a heatsink to avoid overheating the laser head Mount the laser head bracket in a Getting Started 11 Figure 3 Controller to Laser Head Connection 12 Getting Started stable position with the output aperture pointing towards an appropriate beam block Output beam height is two inches See page 16 for details on mounting techniques Position the controller Position the controller within a cable length of the laser head about five feet Make sure that the side and rear vents of the controller are not blocked The controller keyswitch sh
16. 0 910 nm 25 mW TLB 7019 910 945 nm 15 mW TLB 7020 960 995 nm 40 mW TLB 7021 1050 1075 nm 45 mW TLB 7023 1220 1250 nm 15 mW TLB 7024 1270 1330 nm 15 mW TLB 7026 1420 1480 nm 25 mW TLB 7027 1480 1520 nm 30 mW TLB 7028 1520 1570 nm 60 mW TLB 7030 1570 1630 nm 45 mW The actual output power and wavelength range of your laser will only be a fraction of the internal diode power and wavelength range shown here Label Identification The aperture and danger labels shown here pertain to different wavelength laser heads Depending on your specific wavelength requirements other labels similar to those shown may be used 7000 6000 Series User Safety 7 Figure 1 Labels on the front and top of the Vortex and StableWave laser heads Figure 2 Labels on the back of the Vortex and StableWave laser heads 8 User Safety Front of Vortex laser head AVOID EXPOSURE INVISIBLE LASER RADIATION EMITTED FROM THIS APERTURE AVOID EXPOSURE LASER LIGHT EMITTED FROM THIS APERTURE Aperture labels O New Focus 2584 Junction Avenue sion ot Bookham San Jose CA 95134 1902 USA Wavelengths Model Number Serial Number Manufactured Complies with 21 CFR 1040 10 and 1040 11 except for deviations pursuant to Laser Notice No 50 dated JUNE 24 2007 Certification label AVOID EXPOSURE LASER LIGHT IS EMITTED FROM THIS APERTURE AVOID EXPOSURE INVISIBLE LASE
17. 5 corresponding to the combined weight of the bits you want to set Service Request Enable Register Bit Weight Description 7 128 not used 6 64 not used 5 32 Enable the MSS Bit if the Event Summary Bit ESB is enabled 4 16 Enable the MSS Bit if the Mes sage Available Bit MAV is enabled This will not happen under RS 232 3 8 not used 2 4 not used 1 2 not used Example Set the MSS Bit generate a service request when there is data in the output buffer SRE 16 7000 6000 Series Computer Control 43 44 e Computer Control Query Service Request Enable Register Syntax SRE Vortex Actions Queries the Service Request Enable Register Response An integer in the range 0 255 corresponding to the combined weight of the bits that are set See the Set Service Request Enable Register com mand definition on page 43 for a description of the bits and their weights System Information Queries Query Instrument Manufacturing Date Syntax SYSTem INFormation SMANufacture Vortex Actions Returns the date of system manufacture Response mm dd yy Month Day Year Query Instrument Operating Hours Syntax SYSTem INFormation SHOurs Vortex Actions Returns the system operating time Response x Hrs range 0 to 65536 7 5 years Query Laser Head Manufacturing Date
18. C connectors Mounting the Laser Head 16 General Operation Proper mounting of the laser head is essential for stable wavelength operation The output wavelength is strongly dependent on the temperature of the laser cavity which is actively stabilized using a thermoelectric cooler TEC The TEC utilizes the laser head housing as a heat reservoir For this reason the mount for the laser head needs to provide a good thermal path away from the laser head The mounting bracket included with each laser head provides such a path when it is in contact with a large thermal mass such as an optical table The laser head can be mounted with or without the enclosed mounting bracket shipped attached to the laser head Dimensional drawings of the laser head and the mounting bracket are shown in Appendix I on page 60 The mounting bracket is designed for use with metric 25 mm spacing M6 or English one inch spacing 1 4 20 breadboards If you are mounting the laser head without the included mounting bracket take steps to ensure it has an adequate thermal heat sink Setting the Beam Height The laser beam height is one inch 25 4 mm from the bottom of the laser head The mounting bracket adds one additional inch 25 4 mm to the beam height To raise the beam height additional risers are available from New Focus model number 6001 Optically Isolating the Laser After mounting the laser head take precautions to prevent back reflection
19. OOOO 2 Tx Serial Transmit Line 3 Rx Serial Receive Line 4 Not Connected Tt 2 5 4 S Ground Digital Ground Line 6 9 Not Connected 7000 6000 Series Appendix II RS 232 Connector Wiring 63 64 Appendix II RS 232 Connector Wiring mA M Division of Bookham Index A AC voltage checking or changing 55 address setting for GPIB 32 auxiliary input 21 25 B baud rate setting for RS 232 32 beam height 16 beamsplitter 28 bracket mounting 16 C computer control 31 command definitions 38 restoring control to the front panel 22 using the IEEE interface 31 using the RS 232 interface 32 constant power mode 27 preparing for 27 setting up and aligning for 28 switching to 29 controller front panel controls 17 restoring control to the front panel 22 current modulating 24 setting 21 D displaying input signals 21 25 F frequency modulating 23 see also wavelength front panel restoring control 22 front panel controls 17 fuses 56 G GPIB see also IEEE setting the GPIB address 32 H heatsinking 16 height beam 16 help servicing the laser 57 Index 65 technical support 57 high speed current modulation 25 1 IEEE common commands 36 38 computer control 31 setting the GPIB address 32 inputs auxiliary 25 current modulation 24 frequency modulation 23 interlock safety 9 isolation optical 16 K keyswitch 19 L labels safety 7 local mode 17 M mode
20. R RADIATION IS EMITTED FROM THIS APERTURE Front of StableWave laser head Aperture labels O New Focus 2584 Junction Avenue J iinen et msaknam San Jose CA 95134 1902 USA TLB 7000 External Cavity Diode Laser Wavelengths Model Number Serial Number Manufactured Complies with 21 CFR 1040 10 and 1040 11 except for deviations pursuant to Laser Notice No 50 dated JUNE 24 2007 Certification label LASER LIGHT AVOID DIRECT EXPOSURE TO BEAM POWER OUTPUT WAVELENGTH CLASS LASER PRODUCT INVISIBLE LASER RADIATION k AVOID DIRECT EXPOSURE TO BEAM POWER OUTPUT WAVELENGTH CLASS LASER PRODUCT Danger labels O New Focus A Division of Bookham Using the Safety Interlock The safety interlock connector on the back of the Vortex controller is provided for external safety systems The system is shipped with a jumper across the interlock terminals Do not remove this jumper unless you are using the safety interlock feature the laser will not emit light unless the interlock circuit is closed The circuit carries 15 V DC 7000 6000 Series User Safety 9 10 User Safety K M Division of Bookham Getting Started Introduction This section outlines the basic steps needed to start using your StableWave Vortex laser system including information on unpacking the system and brief set up and starting notes For more detailed information on how
21. USER S GUIDE 7000 6000 Series Tunable Diode Laser U S Patents 5 319 668 amp 5 995 521 and European Patent 0 693 231 1 Use of controls or adjustments or performance of procedures other than those specified herein may result CAUTION in hazardous radiation exposure O New Focus A Division of Bookham 2584 Junction Ave San Jose CA 95134 1902 USA phone 408 919 1500 e mail contact newfocus com gt www newfocus com Warranty New Focus Inc a division of Bookham Inc guarantees its StableWave Vortex lasers to be free of material and workmanship defects for one year from the date of shipment or 3 000 hours of operation whichever comes first This warranty is in lieu of all other guarantees expressed or implied and does not cover incidental or consequential loss Please note that each StableWave Vortex laser is custom built to the user s exact wavelength specification Because of the custom nature of this product returns are accepted only within 30 days from the date of purchase and are subject to a restocking fee of 50 of the original cost Products described in this document are covered by U S Patents 5 319 668 and 5 995 521 and European Patent 0 693 231 1 Information in this document is subject to change without notice Copyright 2007 2002 2001 1998 New Focus Inc All rights reserved NEW FOCUS the Bookham Inc logo fost Focus Vortex StableWave and all Bookham Inc names
22. aser Temperature Syntax SENSe TEMPerature Vortex Actions Returns the laser temperature reading Response x xC range 7 0 to 47 0 Power Laser Commands Set Laser Power Syntax SOURce POWer lt power gt Vortex Actions Sets the laser power setpoint when in constant power mode Argument X X range 0 0 to 100 units are in Example Set the laser power to 65 3 SOUR POW 65 3 Query Laser Power Setpoint Syntax SOURce POWer Vortex Actions Queries the laser power setpoint Response In constant power mode xx x range 0 0 to 100 0 In constant current mode xx xmW range 0 0 to Max Power laser specific Example Check the laser power setpoint SOUR POW gt 52 8 O New Focus a y Aen s earnan 7000 6000 Series Sense Laser Power Syntax SENSe POWer Vortex Actions Returns the laser power reading Response In constant power mode range 0 0 to 100 0 In constant current mode xx xmW range 0 0 to Max Power laser specific Wavelength Piezo Voltage Commands Set Piezo Voltage Syntax SOURce VOLTage PIEZo lt voltage gt Vortex Actions Sets the piezo voltage setpoint Argument X X range 0 0 to 117 5 units are volts Example Set the piezo voltage to 88 6 volts SOUR VOLT PIEZ 88 6 Query Piezo Voltage Setpoint
23. case of a system restart command parse error or a query error Computer Control 41 42 Computer Control Query Status Byte Query Syntax STB Vortex Actions Returns the value of the Status Byte Register Response An integer in the range 0 to 255 corresponding to the combined weight of the bits that are set Status Byte Register Bit Weight Description 7 128 not used 6 64 Master Summary Status Bit MSS indicates that one of the bits being watched by the Ser vice Request Enable Register has been enabled 5 32 Event Summary Bit ESB indi cates that one of the bits being watched by the Standard Event Status Enable Register has been enabled 4 16 Message Available Bit MAV indicates that data is being held in the output buffer This will not happen under RS 232 3 8 not used 2 4 not used 1 2 not used 0 1 not used Example Check the Status Byte STB gt 16 there is data in the output buffer K M Division of Bookham Set Service Request Enable Register Syntax SRE lt value gt Vortex Actions Sets the specified bits of the Service Request Enable Register When a corresponding bit in the Status Byte Regis ter becomes true enables bit Master Summary Sta tus Bit MSS of the Status Byte when serial polling generates a service request Argument An integer in the range 0 to 25
24. ch wavelengths simply by changing the laser head heads are available separately The system can be operated manually using the front panel controls or remotely using one of the computer interfaces The StableWave Vortex laser is an external cavity diode laser ECDL based on the Littman Metcalf design see Principles of Operation on page 51 The customer selected wavelength is set and stabilized at the factory using external optics a diffraction grating a mirror and precision temperature control Fine wavelength tuning without mode hops is achieved by rotating the mirror around a fixed rotation point using a piezo electric actuator Laser output power is controlled by an ultra low noise current source The controller contains the electronics for laser current laser temperature and piezo voltage control as well as digital interface electronics A dimensional drawing of the controller is located in Appendix I Physical Specifications on page 59 The temperature of the laser cavity is set at the factory for optimum laser performance and is not adjustable by the user although you can read the temperature using the computer interface see Computer Control on page 31 The laser current controls the optical output power The piezo voltage controls the laser wavelength frequency Both of these parameters can General Operation 5 be adjusted through the front panel controls the computer interface or the back panel BN
25. d irreparably damage the diode Do not exceed the I V _ input and use standard precautions for static discharge when using this input Reading an Input Signal 7000 6000 Series You can monitor an input signal using the Auxiliary Input connector on the back of the Vortex controller This input is also used to run the Vortex in constant power mode see page 27 The Auxiliary Input converts an external analog signal to a digital signal that can be displayed on the front panel or read through the computer interface This is a general purpose input that allows you to collect data General Operation 5 26 General Operation from another instrument such as a photodetector during a wavelength scan Connect the line for the input signal to the BNC connector on the back of the Vortex controller Make sure the signal conforms to the following specifications Auxiliary Input Guidelines Connector Type BNC Voltage Range OV to 4 Input Frequency DC 10 kHz Impedance 10 kQ The update rate for the Auxiliary Input can vary depending on processor demands from 10 100 milliseconds K M Division of Bookham Constant Power Mode Introduction When operating in constant power mode the controller adjusts the laser current to maintain a stable output power Only the power and the laser s wavelength controlled by the piezo voltage can be varied in this mode The laser power displayed in this mode i
26. e Sets current piezo voltage and power to minimum values e Sets the gain to high 25x Argument Response None Clear Status Command Syntax Vortex Actions CLS Clears status reporting structures does not affect the Output Queue or the MAV bit of the Status Byte O New Focus a y Aen s earnan 7000 6000 Series Argument Response None Query Standard Event Status Register Syntax ESR Vortex Actions Returns the value of the Event Status Register and then clears the register returns all bits to 0 Response Example An integer in the range 0 to 255 corresponding to the combined weight of the bits that are set Standard Event Status Register Bit Weight Description 7 128 Power on or restart 6 64 not used 5 32 IEEE a command parse error RS 232 not used 4 16 IEEE system not available for command or invalid data out of range For example attempting to change modes while the laser diode power is on RS 232 not used 3 8 not used 2 4 Query error no data in queue 1 2 not used 0 1 not used Determine if the system has been restarted since the last time this query was made ESR gt 160 160 128 32 the system has been restarted and there was a command parse error Computer Control 39 40 Computer Control Set Standard Event Status Enable
27. e tuning range of the laser A recommended beam pick off is the New Focus Model 5801 wedged Beam Pick off Photodetector An external photodetector is needed to measure the power in the beam sampled by the beamsplitter The detector gain must be large enough to generate a signal of 4 V when the laser is operating at its maximum output power For example with a full output power of 10 mW anda 10 beamsplitter the detector conversion gain must be 4000 V W Recommended detectors are the New Focus 2001 and 2011 as they provide sufficient gain and the gain is adjustable Operating in Constant Power Mode Setting up and Aligning the Laser Before switching to constant power mode use the StableWave Vortex in constant current mode to set up and align the laser 1 Turn on the StableWave Vortex keyswitch and allow the system 0 minutes to warm up 2 Ifthe Constant Power indicator is on press the Mode button to switch the laser to constant current mode 3 Push the Power button to activate laser power 4 Turn up the laser current to the recommended operating current as specified in the Acceptance Test Data Sheet 5 Direct the output beam through the beamsplitter 6 Direct the sample beam onto the photodetector Use caution to prevent back reflections into the laser 7 Connect the photodetector output to the Auxiliary Input on the back of the StableWave Vortex controller 8 On the controller press the Display button until t
28. eck the voltage setting look at the voltage indicator on the back of the Vortex controller Figure 7 AC power module amp voltage indicator Voltage indicator To change the operating voltage 1 Disconnect the AC power cord 2 Open the cover of the power module on the rear panel with a small blade screwdriver or similar tool Figure 8 Power Module with the cover open 7000 6000 Series Changing the AC Voltage Selection 55 3 Remove the AC voltage selection wheel from the unit Do not attempt to rotate the wheel while it is still in the power entry module the wheel must be removed turned and then reinserted for proper operation 4 Re insert the wheel into the module so the desired AC voltage can be viewed in the power module window 5 Ensure the proper fuses are installed in your system The power entry module requires two 5x20 mm slow blow fuses such as Littelfuse s Slo Blo 239 series one for the hot line and the other for the neutral line Replacement fuses should be as follows Figure 9 AC Voltages and AC Voltage Fuse Rating Slo Blo Fuse their sel e 100 V AC 1 25 239 1 25 recommended fuses 120 V AV 1 25 239 1 25 220 V AC 0 6 239 600 240 V AC 0 6 239 600 6 Close the power module cover 7 Verify the proper voltage is showing through the module window 8 Reconnect the AC power cord 56 Changing the AC Voltage Selectio
29. er Control Introduction The StableWave Vortex laser system can be operated remotely through either the parallel IEEE 488 GPIB interface or the serial RS 232 interface Most computers have RS 232 interfaces built in In order to use the IEEE 488 interface a special card or interface box is necessary The IEEE 488 interface is many times faster than the RS 232 interface and can be used to communicate with up to 30 instruments at the same time RS 232 is limited to communication with one instrument at a time All front panel operations are available through computer control In addition several functions are unique to computer control Before attempting to communicate with the instrument you must set the device address for IEEE 488 or the baud rate for RS 232 via the front panel Upon receiving a command over the computer interface the front panel functions are locked out Use the Local button on the front panel to re enable the front panel Using the IEEE 488 Interface 7000 6000 Series The IEEE connector on the back of the StableWave Vortex controller allows for remote operation through a standard IEEE 488 GPIB cable The connector is a standard female 24 pin IEEE 488 connector for use with a standard shielded IEEE 488 cable In order to function properly the StableWave Vortex must have a GPIB address that is unique from all the other IEEE 488 components attached to your computer Computer Control 1 Setting t
30. er and in constant power mode you can t adjust the current To adjust the set value for the parameter enable the Set button and turn the adjustment knob General Operation 1 Turn the knob clockwise to increase the value counter clockwise to decrease the value The knob has a built in acceleration feature to make large changes turn the knob quickly Restoring Local Front Panel Control When the StableWave Vortex receives a command from the computer interface it deactivates most of the front panel controls This remote control mode is indicated by the Remote LED on the front panel To return the controller to local front panel control press the Local button on the front panel Modulating the Laser Output The StableWave Vortex allows you to modulate the frequency or the current of the laser For frequency modulation connect your signal to the Frequency Modulation connector on the back of the controller For current modulation you can use the DC coupled Current Modulation BNC input on the back of the controller On the Vortex there is also an additional high speed SMA input on the back of the laser head Figure 6 Controller back panel mes o afieii pe 7 TAREHE e inane Taput Laser 0000000000000 IEEE 488 ommo S o D 7 7 High Speed Current Frequency and Current Modulation Inputs Modulation Input You can
31. he StableWave Vortex GPIB address 1 Press the GPIB Address button on the front panel to display the GPIB address for the StableWave Vortex If it is not already lit press the Set button to enable the adjustment knob Turn the adjustment knob to change the setting Turn the knob clockwise to increase the value counter clockwise to decrease the value Press the GPIB Address button again to return to the normal display Using the RS 232 Interface The RS 232 9 pin connector on the back of the StableWave Vortex controller allows for remote operation through a standard 9 pin RS 232 cable see page 63 To use the RS 232 port attach a standard shielded RS 232 cable to the connector 32 Computer Control To communicate with the StableWave Vortex set your computer to 8 data bit no parity checking 1 stop bit no hardware handshake The StableWave Vortex can support baud rates between 300 and 57 600 bps Setting the Baud Rate for RS 232 1 Press the Baud Rate button on the front panel to display 1 0 2 baud rate If it is not already lit press the Set button to enable the adjustment knob Turn the adjustment knob to change the setting Turn the knob clockwise to increase the value counter clockwise to decrease the value Available baud rates are 300 1200 2400 4800 9600 19200 38400 and 57600 Press the Baud Rate button again to return to the normal display O New Focus a y Aen s earnan Resto
32. he display shows the reading for the auxiliary input Aux x x 28 Constant Power Mode PERE 9 Adjust the beam position on the photodetector to maximize the voltage being displayed 10 Adjust the gain of the detector to achieve a reading of about 4 V keeping the current set to the recommended operating current Switching to Constant Power Mode 1 If laser power is on push the Power button to turn off power to the laser power must be off to switch modes Push the Mode button to change the StableWave Vortex into constant power mode The Constant Power indicator will go on and the display will change to show the output power the units will be in Push the Power button to re activate laser power Set the desired power level by adjusting the level If the Set button is not already lit you will need to press it to enable the adjustment knob In order to operate in constant power mode you must operate at less than 100 to ensure that the laser controller can adjust the current to provide a constant power level The operational power is dependent on your specific laser and the variation in power over your tuning range power mode this interrupts the feedback loop and will push the laser 0 Do not block the beam incident on the photodetector when in constant ARNING output to maximum power 7000 6000 Series Constant Power Mode 29 30 Constant Power Mode g M Division of Bookham Comput
33. ller Make sure the signal conforms to the following specifications Current Modulation Input Guidelines DC coupled Connector Type BNC Max Voltage 10V Input Frequency Range 6 1 MHz Impedance 50 Modulation 0 2 mA V The DC coupled Current Modulation input is NOT current limited To prevent damage to the laser diode DO NOT modulate the current above the operating current specified in the Acceptance Test Data Sheet The front panel current readout does not reflect the modulation input You can calculate the actual current by adding the current shown on the front panel display to the modulation input O New Focus a y Aen st Bearnan WARNING Cas WARNING Using the High Speed Current Modulation Input You can use the SMA connector on the back of the laser head to modulate the current at high speeds 1 Turn off the diode power the light in the Power button should be off Failure to turn off the diode power before connecting the RF input could permanently damage the laser diode 2 Connect the line for the input signal to the SMA connector on the back of the Vortex laser head Make sure the signal conforms to the following specifications Current Modulation Input Guidelines High Speed Connector Type SMA Max Voltage 1 Vp p Input Frequency Range 50 kHz 100 MHz Impedance 50Q Modulation 20 mA V This is a direct RF connection to the laser diode Improper use coul
34. ls wavelength or auxiliary input voltage The operating mode constant current or constant power determines which parameters you can adjust 7000 6000 Series 1 Press the Display button to view the parameter you want The units on the display indicate which parameter is active Laser current is displayed as mA e Laser power is displayed as mW in constant current mode and as x x when in constant power mode In constant current mode the power is read from the back of the laser diode and is therefore only accurate to approximately 20 of the true laser output power There are certain special models that don t have a built in photodetector In these cases the display will not be active and only 0 mW will be shown e Piezo voltage is displayed as x x V This is a direct readout of voltage to the piezoelectric actuator that controls the wavelength Increasing the voltage decreases the wavelength increases the frequency The voltage range is 0 117 5 V e Auxiliary input is displayed as aux x xx not adjustable Switch the Set button on or off depending on the value you want to see If the LED in the Set button is lit then the display will show the set value of the parameter if the LED is not lit then the display will show the operating value If the LED does not go on then you cannot adjust the displayed value For example in constant current mode you can t adjust the pow
35. mmand Page SOUR CURR lt current gt Set Diode Current 47 SOUR CURR Query Diode Current Setpoint 47 SENS CURR Sense Diode Current 47 SENS TEMP Sense Laser Temperature 48 Power Laser Commands Syntax Command Page OUTP lt power gt Turn On Off Power to Laser Head 46 OUTP Query Laser Head Power 46 SOUR POW lt voltage gt Set Laser Output Power 48 SOUR POW Query Laser Power Setpoint 48 SENS POW Sense Laser Power 49 Wavelength Piezo Voltage Commands Syntax Command Page SOUR VOLT PIEZ Set Piezo Voltage 49 lt current gt SOUR VOLT PIEZ Query Piezo Voltage Setpoint 49 SENS VOLT PIEZ Sense Piezo Voltage 49 CONF GAIN lt gain gt Set Frequency Modulation Gain 50 CONF GAIN Query Frequency Modulation Gain 50 Computer Control 37 Command Definitions 38 Computer Control IEEE 488 2 Common Commands Identification Query Syntax Vortex Actions IDN Returns the system identification string containing the manufacturer model numbers serial numbers and firmware revision Example TDN gt New Focus 0 H6013 1059 H623 3 3 Manufacturer New Focus Controller Model 6000 Head Model 6013 Controller S N 059 Head S N 623 Firmware ver 3 3 Reset Command Syntax RST Vortex Actions Resets internal operations of the StableWave Vortex Turns off laser diode e Sets the laser to constant current mode
36. n PERE Customer Service Service The StableWave Vortex is designed as a maintenance free laser thus there are no scheduled service actions If your laser does require service repair or calibration please call for a Return Authorization Number before shipping the unit to New Focus Technical Support 7000 6000 Series Information and advice about the performance or operation of your StableWave Vortex laser is available from our applications engineers For quickest response ask for Technical Support and have your model and serial number available The model and serial number can be read from the top of the laser head label or displayed on the controller front panel by simultaneously pressing the GPIB Address and Baud Rate buttons Hours 8 00 5 00 PST Monday through Friday excluding holidays Toll Free 1 866 NUFOCUS 1 866 683 6287 from the USA amp Canada only Phone 408 284 6808 Support is also available by fax and email Fax 408 980 8883 Email techsupport newfocus com We typically respond to faxes and email within one business day Customer Service 57 58 Customer Service pron Focus Appendix l Physical Specifications Controller Controller Weight 14 Ibs 7 kg 7000 6000 Series Appendix I Physical Specifications 59 Vortex Laser Head and Mounting Bracket 5 1 000 2 49 gt 3 750 gt 3 6097
37. ould be off position 0 Connect the head and controller Connect the controller to the laser head with the 26 pin D connector laser cable provided Use only the supplied New Focus laser cable to connect the controller to the laser head To ensure proper and safe operation of the laser secure the cable to the laser head and controller using the captive attachment screws in the cable s D connectors Ea pe g 5 Be ER 5 58 56 8 ER 8 ga 0 20000000000 2000000000000 110 0 8 RS232 96088 5 1 ee 4 5 F IEEE 488 D Connector Laser Cable Connect the power cord Attach the power cord to the controller and plug it into a wall outlet This instrument is configured at the factory for the line voltage and frequency appropriate for your country If you are unsure of how your unit is configured see Changing the AC Voltage Selection on page 55 O New Focus a y Aen e Bearna 5 Optically isolate the laser Take precautions to prevent back reflections into the laser head Isolation can be achieved by angling your optics or with the use of an optical isolator The degree of isolation required depends on how you are using the laser contact New Focus technical support for help with your particular application Starting the StableWave Vortex for the First Time The following section takes you through the basic steps of starting up and
38. r a hardware EOI is detected IEEE 488 Numbers may contain at most 15 characters Commands that expect integer values will truncate after any decimal point in the input For example an input value of 11 56 is truncated to 11 Only one command can be issued per line The IEEE 488 2 Common Commands are adopted from the IEEE 488 2 standard For more information on the standard see IEEE Standard Codes Formats Protocols and Common Commands IEEE Std 488 2 1992 published by the Institute of Electrical and Electronics Engineers Inc 345 East 47th St New York NY 10017 USA O New Focus a y Aen s earnan e For IEEE 488 the Status Byte is very important to successful communication with the StableWave Vortex The Message Available MAV bit in the Status Byte indicates whether or not data is waiting in the output buffer Always check that the MAV bit is set before reading back information If the output buffer is empty the read will fail The best way to check the Status Byte is to use a serial poll A serial poll returns the same information as the STB query but it bypasses the output buffer the Vortex places the STB response in the output queue and it can t be read until all other responses are read The RS 232 interface does not support serial polling so you would have to use the STB command to query the Status Byte However since the Vortex sends RS 232 responses and errors directly withou
39. ring Local Front Panel Control When the StableWave Vortex receives a command from the computer interface it deactivates most of the front panel controls This remote control mode is indicated by the Remote LED on the front panel To return the controller to local front panel control press the Local button on the front panel Understanding the Command Types There are three types of commands understood by the Stable Wave Vortex Set commands Query commands and Sense commands Use Set commands to set or change a value Examples would be commands that turn on the laser head or set the operating current e Use Query commands to check the user or factory set values of the laser Examples include checking the set value for the current and checking the number of hours of operation Use Sense commands to determine the actual values for the laser properties at any given time For example to check the actual operating current or the voltage from the auxiliary input Sense and Query commands evoke a response from the driver If you are using RS 232 the response is sent immediately with IEEE 488 the response is loaded into the output buffer a first in first out buffer with a capacity of 5 messages There is no response from Set commands if they are accepted and properly executed Conventions 7000 6000 Series The following pages contain a summary of all available commands followed by detailed definitions for
40. rrent on page 24 Modulating the frequency over the full tuning range 1 Use the StableWave Vortex front panel to set the piezo voltage to 59 V 2 Set the input voltage to a maximum 4 5 Vp p 2 25 V to 2 25 V If you used the computer interface to change the gain to low a gain factor of 1 you will not be able to modulate the frequency over the entire tuning range for information on using the computer interface see Computer Control on page 31 General Operation 23 WARNING 24 General Operation Modulating the Current To modulate the current you can use either the DC coupled Current Modulation BNC input on the back of the controller or the high speed SMA input on the back of the laser head Since changes in the current affect the laser frequency you may want to modulate the current in order to achieve fine frequency modulation The frequency modulation is due to changes in the index of refraction of the laser gain medium the semiconductor diode as a function of laser current The degree to which the current affects the wavelength depends on the specific laser head you are using but it is in the range of 25 150 MHz mA Using the DC Coupled Current Modulation Input Vortex Only You can modulate the laser current amplitude using an externally generated low level signal To modulate the current connect the line for the input signal to the Current Modulation connector on the back of the Vortex contro
41. s constant power 27 constant power 27 selecting an operating mode 19 setting the operating mode 20 modulating current 24 frequency 23 mounting bracket 16 mounting the laser head 16 O optical isolation 16 66 Index P parameters displaying and setting 21 photodetector 28 piezo voltage wavelength modulating 23 setting 21 power constant power mode 27 maximum diode powers 6 7 setting 21 turning on the StableWave Vortex 19 R remote mode 17 restoring control to the front panel 22 RS 232 computer control 31 setting the baud rate 32 using 32 wiring diagram 63 5 safety interlock 9 safety labels identifying 7 servicing the laser 57 support technical 57 1 technical support 7 temperature considerations heatsinking 16 warming up 19 turning on the StableWave Vortex 19 V voltage checking or changing AC voltage 55 New Focus A Division of Bookham setting piezo voltage 21 W warming up the StableWave Vortex 19 wavelength modulating 23 ranges by model number 6 7 tuning 21 wiring diagram RS 232 connector 63 Index 67 68 Index Rew Focus A Division of Bookham
42. s given in terms of a percentage of maximum auxiliary signal input The feedback circuit electronics that control constant power mode are internal to the StableWave Vortex controller but you will need an external beamsplitter and photodetector to provide the controller with the necessary electrical signal for the internal feedback circuit Preparing to Use Constant Power Mode 7000 6000 Series Constant power mode uses a feedback signal from the Auxiliary Input to stabilize the laser s output power Operating the StableWave Vortex laser in constant power mode is a three step process 1 Set up an external beamsplitter to pick off a portion of the output beam and direct it into a photodetector 2 Feed the signal from the photodetector into the controller s auxiliary input 3 Generate a setpoint based on a percentage of the maximum output power using either the front panel or computer control The StableWave Vortex controller will compare the output measured by the photodetector to the setpoint you entered and actively adjust the laser current to stabilize the output power Following are the specifications for the external components you will need to supply Constant Power Mode 27 Beamsplitter An external beamsplitter is needed to sample the laser output The reflectivity of the beamsplitter at the StableWave Vortex wavelength should be approximately 10 The beamsplitter should also have a constant reflectivity over th
43. s into the laser aperture Isolation can be achieved by angling your optics or with the use of an optical isolator The degree of isolation required depends on how you are using the laser contact New Focus technical support for help with your particular application O New Focus a y Aen s earnan Using the Front Panel Controls Figure 5 Controller front panel 7000 6000 Series The StableWave Vortex has two control options local and remote In local mode the front panel provides control of the laser system In remote mode you control the laser over the computer interface IEEE 488 or RS 232 Whenever the StableWave Vortex receives a command over the computer interface it automatically deactivates most of the front panel controls the Local button which restores local control and the Power button and power keyswitch all remain active For information on using computer control see page 31 The controls on the front panel Figure 5 allow you to switch system operating modes and to read and set the laser current laser power piezo voltage which controls the laser wavelength and computer interface parameters Constant Power GPIB Addres Baud Ratle 6 7 8 9 10 IL 12 13 14 1 Display The display shows the various laser parameters as well as errors and system identification information Vortex Laser Controll r 6000 Constant Current i 0 Remote 2 Constant Current Indica
44. s of laser and system parameters Local Button Returns the controller to local front panel control when the driver is in remote computer control GPIB Address Button Displays the GPIB IEEE address setting See Using the IEEE 488 Interface on page 31 for more information Baud Rate Button Displays the RS 232 baud rate setting See Using the RS 232 Interface on page 32 for more information O New Focus a Aen s Beannan Turning on the Power Before turning on the system for the first time check that the AC line voltage indicator on the back of the controller matches the voltage you are using see page 55 To turn on the StableWave Vortex 1 Turn the power keyswitch on the front panel clockwise to the position This turns on AC power for the entire laser system including the temperature circuit in the laser head 2 Wait at least 20 minutes after turning on the keyswitch to allow the laser head to reach a stable temperature 3 Press the Power button on the controller front panel to allow current to flow to the laser head The button will flash during the five second safety delay before the current is activated The button will remain lit while current is flowing to the laser diode The diode will not emit laser light until the current is set high enough to meet the threshold current Before turning off the system you should first turn off power to the laser diode by pressing the Power bu
45. shutting down the laser The controls and functions are described in more detail in the following chapter Figure 4 Laser Controller nn Front Panel Vortex Laser Controller 6000 irrent Constant Cu Constant Power g Mode Display Set 8 Power Local Made in USA NEW FOCUS eet a iress paua Rate 1 1 Turn on the system Turn the keyswitch to ON position The system will start up in constant current mode with the current set to 0 mA and the system ID will scroll across the display After turning the keyswitch allow the system a minimum of 20 minutes to reach a stable temperature before turning on the laser diode step 4 Once the keyswitch is turned on the system can be operated remotely through the IEEE 488 GPIB or RS 232 ports Refer to the Computer Control chapter beginning on page 31 for details 2 Set the operating mode An LED on the front panel will indicate the system s operating mode constant current or constant power To change modes press the Mode button You will need to use an external photodetector to operate the StableWave Vortex in constant power mode See Selecting an 7000 6000 Series Getting Started 13 WARNING 14 Getting Started Operating Mode on page 19 for details on the different modes or the Constant Power Mode chapter beginning on page 27 for details on setting up and using the laser in constant power mode
46. t using the output buffer there is rarely if ever a reason to read the output buffer 7000 6000 Series Computer Control 35 Command Summary IEEE 488 2 Common Commands Syntax Command Page IDN Identification Query 38 RST Reset 38 CLS Clear Status 38 ESR Query Standard Event Status Register 39 ESE lt value gt Set Standard Event Status Enable Register 40 ESE Query Standard Event Status Enable Regis 41 ter STB Query Status Byte 42 SRE lt value gt Set Service Request Enable Register 43 SRE Query Service Request Enable Register 44 System Information Queries Syntax Command Page SYST INF SMAN Instrument Manufacturing Date 44 SYST INF HMAN Laser Head Manufacturing Date 44 SYST INF SHO Instrument Operating Hours 44 SYST INF DHO Laser Head Operating Hours 45 SYST INF HWAV Laser Head Wavelength 45 System Commands Syntax Command Page CONF MOD lt mode gt Set System Operating Mode 45 CONF MOD Query System Operating Mode 45 OUTP lt power gt Turn On Off Power to the Laser Head 46 36 Computer Control K M Division of Bookham 7000 6000 Series Syntax Command Page OUTP Query Laser Head Power 46 SENS VOLT AUX Sense Auxiliary Voltage 46 Current Diode Commands Syntax Co
47. tor This indicator is lit when the laser is set for constant current mode 3 Constant Power Indicator This indicator is lit when the laser is set for constant power mode General Operation 17 18 General Operation 10 11 12 13 14 Addressed Indicator This indicator is lit whenever the controller is communicating over the computer interface see the Computer Control chapter beginning on page 31 Remote Indicator This indicator is lit whenever the controller is under computer control via either the IEEE 488 GPIB or the RS 232 interface See Computer Control on page 31 Power Keyswitch Controls AC power to the entire laser system including the temperature circuit in the laser head Power Button Turns on and off current to the laser diode Mode Button Switches the laser between constant current and constant power modes power to the laser diode must be off to switch modes Constant power mode requires an external beamsplitter and photodetector See the Constant Power Mode chapter beginning on page 27 for details Display Button Changes the display to show laser current laser power piezo voltage or auxiliary input voltage Set Button Activates de activates the adjustment knob so you can adjust the displayed laser parameter the properties you can control depend on the operating mode Adjustment Knob When activated by the Set button this knob is used for all adjustment
48. tton Selecting an Operating Mode 7000 6000 Series The StableWave Vortex laser current driver operates in either constant current mode or constant power mode Constant current mode results in narrower laser linewidth while constant power mode results in the lowest intensity fluctuations The constant current or constant power indicator on the controller display will indicate the active mode Constant Current Mode When operating in constant current mode the controller maintains a stable set current with the low noise current driver This results in a narrow laser linewidth General Operation 19 20 General Operation While in constant current mode you can adjust the diode current and laser wavelength piezo voltage To change one of these parameters from the front panel display the current mA or piezo voltage V press the Set button so it is lit and turn the adjustment knob The laser power is not adjustable in this mode the power is read from the back facet of the laser diode and is only accurate to within about 20 of the true laser output power Each laser head is designed and built for a specific operating current and has a factory limited maximum current level to prevent possible damage to the laser diode This current limit also limits the maximum power output from the laser head Constant Power Mode When operating in constant power mode the controller adjusts the laser current to maintain a stable output
49. ver a 50 msec time interval compared with typical linewidths for Fabry Perot diode lasers of 10 500 MHz General Theory The StableWave Vortex HR ig ree Littman Metcalf Laser Cavity laser cavity is based on the Littman Metcalf design see refs on page 53 which uses a Collimating Lens AR Coating Retroreflector diffraction grating at grazing incidence to isie provide wavelength selectivity Essential to pened the performance of tunable external cavity diode lasers ECDLs is a high quality anti reflection AR coating on the front facet of the diode The AR coating turns the diode into purely a gain element A collimating lens directs the output of the diode across a diffraction grating at grazing incidence The end mirror of the laser cavity reflects the first order diffraction off the grating to provide feedback Dispersion provided by the grating 7000 6000 Series Principles of Operation 1 allows only one cavity mode to lase resulting in a very narrow linewidth The specular reflection or zero order diffraction off the grating serves as the output beam of the laser The angle between the grating and the end mirror determines the lasing wavelength Tuning is achieved by varying the angle using a piezoelectric actuator to rotate the end mirror Continuous mode hop free tuning requires selecting an appropriate rotation point Discontinuous tuning characterized by periodic mode hops
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