818-IS-1 Manual 4148 - Newport Corporation
Contents
1. that all items are present and are in good condition Carrying case Detector body with two blank plugs and baseplate installed Adapters for ST FC and SC connectors Adapter for bare fibers Two Allen keys Extra bolts for connectorized fiber adapters and the baseplate Dust caps for the connector adapters Calibration data sheet NOTE There are no user serviceable components inside the 818 IS 1 Disassembly of the detector will most likely damage delicate internal components and will result in a loss of certified cali bration as well as voiding of all warranties Connection to Newport s Power Meters The 818 IS 1 has a mini DIN connector integrated to the end of the cable This connector is intended only to be plugged into Newport power meters that are compatible with calibration modules NOTE The photodiodes used in the 818 IS 1 are designed for high performance when used with an amplifier that provides a vir tual ground such as Newport s power meters These detectors are not designed to tolerate bias voltages of any kind Exposure to reverse voltages in excess of that given in the specifications or to forward voltages of any magnitude can damage the photodiodes Also as explained below the detec tor will not give accurate or linear measurements when biased or when driving a resistive load such as an oscilloscope input Calibration The 818 IS 1 comes with its calibration data individually encoded on a progra2. Warranty Newport Corporation warrants this product to be free from defects in material and workmanship for a period of 1 year from the date of shipment If found to be defec tive during the warranty period the product will either be repaired or replaced at Newport s option To exercise this warranty write or call your local Newport representative or contact Newport headquarters in Irvine California You will be given prompt assistance and return instructions Send the detector transportation prepaid to the indicated service facility Repairs will be made and the detector returned transportation prepaid Repaired products are warranted for the balance of the original warranty period or at least 90 days Limitation of Warranty This warranty does not apply to defects resulting from modification or misuse of any product or part This warranty is in lieu of all other warranties expressed or implied including any implied warranty of merchantability or fitness for a particular use Newport Corporation shall not be liable for any indirect special or consequential damages Copyright 1996 Newport Corporation Part No 22308 01 Rev C Table of Contents Page YY I a E cuvadecedaceds nesceceuanesaceusdeuscaeacuadeoseusaaedaae 2 TOR OLC ON N n E E E E E EEE E EEEE 3 Specifications ee peesae ec cesses acenene snes sa ncieneaiseacenpaeesamens saseeueaeasceuseeasaeesaseaneanegeseueastascienemunae 4 DESETO e A O E E A pret eeretr errr a
3. der included with every 818 IS 1 detector sold This port should not be used with other adapters such as the FP3 and FP4 series since the fiber tip will be in the wrong position relative to the port entrance The natural spreading of the light as it exits the fiber will cause much of the light to strike the area around the port where it cannot be measured When using the FP3 FH1 the position of the fiber in the chuck is not very critical The fiber tip can be exactly flush to the tip of the holder or can protrude as much as 0 25 6 mm without affecting the measurement accuracy If the fiber pro trudes more than this damage to the fiber or the interior of the sphere becomes possible The port receptacle is designed so that if the fiber protrudes less than 25 the adapter will align itself as you insert it to prevent damage to the fiber tip You may use angled cleaves or angle polished ferrules to reduce backreflection without affecting measurement accuracy The detector is also fairly insensitive to cleave quality since the light is fully integrated before being measured However for best results cleave quality should be reasonably good The front port of the 818 IS 1 is designed to be used with any of the other adapters that come with the detector FP3 and FP4 series adapters should not be used on this port since they do not position the ferrule tip properly for accurate measurement The 818 IS 1 is designed for fibers with nume
4. e 5 Unpacking and TAS PCC UO sss csscansrarcecedncnunesonapsnesineashasceassnasoyepsaapapesswensbanseesanennescnaponsoans 6 Connection to NEw port S Power MG CIS xc oicsascewsavesnnneeaxsaecnecaseennecesaenaeesncarsareovenseanneneest 6 ITE TOM a A E f Fiber PreparaN OU secsec ienien enea eeaeee aea aa aaaea Eo SE EnEn Erana Eein 8 BY ALTE AON cassentrinssacntasscoustesacnentsieioeeusielmenenciodeasuateicnescndeseanuetuienendmteseoacntycinenuadeueasenencssouetacdse 9 Ambient Light and Electrical OFFSETS cxccexcecoeu rescence erence cncaenceen 10 Spectral range Saturation Power Saturation Energy Saturation current Max Ave Power Max Pulse Energy Accuracy Responsivity Risetime Shunt Resistance Die Capacitance Max Reverse Bias NEP Operating Temperature Range Storage Temperature Range Material Specifications 400 1600 nm gt 200 mW gt 1J 10 15 ns pulse gt 2mA 250 mW Bare fiber 1 W Connectorized 100 uJ 2 5 gt 0 0025 400 1600 nm gt 0 005 600 1600 nm lt 2 us gt 20 MQ lt 800 pF 2V lt 10 pW Hz 10 to 55C 10 to 55C InGaAs Si 1 Specified at Calibration Temperature Description The Model 818 IS 1 universal fiber optic detector is an integrating sphere based detector designed for accurate measurements from all types of fiber optic sources The detector uses a dual port dual detector design patent pending to provide maximum versati
5. lity over a broad range of wavelengths and sources A variety of adapters are available for the front port to facilitate measurements from connector ized fibers The rear port is designed to measure light from bare fibers using the FP3 FH1 bare fiber holder A complete kit of adapters is included with each detec tor together with a rugged case for storage and transportation The 818 IS 1 uses a symmetrical integrating sphere design to ensure accurate cali bration regardless of the fiber type or port used The detector uses a novel dual detector design with special optics that improve temperature sensitivity markedly from ordinary detectors The sphere is constructed from a highly reflective ther moplastic which gives much better calibration stability under varying conditions of temperature humidity and long term usage than conventional coated spheres Each detector is fully calibrated over the wavelength range of 400 1600 nm and the individual calibration data and certification is provided with the detector Calibration data is also encoded in a programmable read only memory integral to the electrical connector The Model 818 IS 1 is compatible with all of Newport s power meters that use calibration modules The drawing below shows how the supplied adapters can be connected to the detector to make power measurements Unpacking and Inspection The 818 IS 1 includes the following items in addition to this manual Please make sure
6. m mable read only device built into the connector In order to make use of this fea ture to obtain accurate power measurements however you must make sure that the power meter is using the correct data Please note that Newport s power meters read the entire data set from the read only memory in the connector only on power up If you change detectors you must reboot the power meter in order to ensure that the meter is using the correct calibration constants This can be accomplished by means of the reset button on the rear of the instrument see the owner s manual for your power meter for details or by cycling the power switch off then on Also be sure that the wavelength is set correctly for the source you are measuring or inaccurate readings will result Statement of Calibration The accuracy and calibration of this photodetector are trace able to NIST or NPL through equipment which is calibrated at planned intervals to certified standards maintained at Newport Corporation NOTE The performance and calibration of the integrating sphere based measurement system depends on the reflectance of the material from which the sphere walls are made It 1s impera tive that these walls be protected from contamination that could lower their reflectance Dust caps and port plugs are provided to keep dust out of the detector These should be used whenever possible particularly if the detector is to be used in a dirty environment Excessi
7. nt resistance with voltage offsets in the amplifier circuitry Because the 818 IS 1 uses very high quality detectors this off set will be quite small less than 250 fA of equivalent photocurrent is typical with Newport power meters This offset can be removed by use of the power meter s zero function Please note however that the offset is a function of the temperature of both the photodiode and the amplifier inside the power meter So when mea suring very low light levels it 1s best to rezero the meter whenever you think that the temperature of the detector or the power meter may have changed For instance it is good practice to rezero the meter after a warm up period of about 30 minutes Refer to your power meter manual for details regarding the zeroing procedure 10 11 Newport Corporation Worldwide Headquarters 1791 Deere Avenue Irvine CA 92606 In U S 800 222 6440 Tel 949 863 3144 Fax 949 253 1680 Internet sales newport com QD Visit Newport Online at www newport com Printed in the USA
8. rical apertures of 0 29 or less Higher numerical apertures can result in part of the beam striking the interior of the port before entering the sphere This can cause a modest degradation in mea surement accuracy Saturation The 818 IS 1 is designed to accurately measure photocurrents only up to the rated saturation current Beyond this level measured power will become nonlinear due to voltages generated by the photocurrent as it passes through the series resis tances of the detectors The saturation current is not a function of wavelength but the maximum power measurable before saturation occurs is since the responsivity ratio of photocurrent generated to optical power applied of the detector system is a function of wavelength The maximum power specification given in the detector specifications table is a worst case value and is guaranteed at any wavelength The Model 818 IS 1 can be used to measure pulsed light sources but precautions must be taken to ensure accurate results The pulsed saturation level see the spec ifications table on page 4 of the detector must not be exceeded Also since it is difficult to make accurate energy measurements of single pulses with semiconduc tor detectors continuous pulse trains should be used The average pulse energy may be obtained by dividing the power reading by the pulse repetition rate See your power meter manual for details NOTE The 818 IS 1 is designed to provide calibrated attenua
9. tion of input light in order to accurately measure high light levels without using an attenuator As indicated in the specifica tions the maximum measurable light level of the detector is quite high Please note however that the 818 IS 1 is designed to measure light from fiber sources where the cone shaped beam emitted from the fiber tip ensures that the beam will be spread out before it strikes the reflective material of the sphere This material is rated at 8 J cm2 and this value should not be exceeded Ambient Light and Electrical Offsets Good measurement technique dictates that the effects of ambient light should be reduced as much as practical when using photodiodes Although the photocurrent generated by ambient light can be easily zeroed out the shot noise associated with the photocurrent will not be zeroed nor will any changes in the ambient light lev els which might be caused by people moving around in the room The 818 IS 1 is much less sensitive to ambient light than most detectors because of the small port size However when using the detector we recommend that the port that is not in use be plugged with one of the blank plugs supplied with the detector This also ensures that dirt and other contamination cannot enter the port Ambient light will be blocked from the port in use by the adapter itself A small electronic offset will always be present with semiconductor detectors caused by an interaction of the detector shu
10. ve oil contamination in the air can cause long term calibration shifts and should thus be avoided NOTE The 818 IS 1 is designed to be a rugged assembly for use in production and laboratory environments However it is a cali brated optical instrument and is thus vulnerable to mechani cal shock If your detector is dropped it may have to be inspected and recalibrated at the factory Exposure to temper atures beyond those specified for storage can also create mechanical stresses which may also affect the performance and calibration of the detector All semiconductor detectors display temperature sensitivity which affects their responsivity This sensitivity is usually more pronounced in a specific range of wavelengths particular to the material used for the detector The dual detector bal anced design used in the 818 IS 1 largely eliminates these temperature sensitivi ties to give very accurate measurements over a very broad range However the inherent temperature sensitivity is not entirely removed Therefore it is wise to use the detector at or near the calibration temperature whenever possible The calibra tion temperature is given on the individual calibration report that ships with every detector Fiber Preparation The 818 IS 1 detector uses a dual port design to allow measurement from a vari ety of fiber sources The rear port the end the blue cable exits from is designed to be used with Newport s FP3 FH1 bare fiber hol
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