SERIES PVI-2TE 2-12 Âµm IR PHOTOVOLTAIC DETECTORS ...

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Boston Electronics Corporation91 Boylston Street, Brookline, Massachusetts 02445 USA(800)347-5445 or (617)566-3821 fax (617)731-0935www.boselec.comboselec@world.std.comWhen do I need to use a preamp? (and other comments onsignal levels and device saturation)One of the very convenient things about Vigo MCT detectors is that many users will not require a preamplifier but can insteadgo directly into an oscilloscope for display of fast transients, usually laser pulses. When is this the case and when not? Briefly,the answer is, for a CW signal, you probably need a preamp, and for short pulses widely spaced in time, you probably do notneed a preamp.The question relates to saturation levels in the detector. We consider “saturation” to be the point at which the detector outputdeviates from linear by 20%. You might want to choose another percentage deviation from linearity, but the idea remains thesame and in fact, once saturation begins it seems to happen quickly so there will not be a large difference whether we speak of1%, 20% or 50% deviation.Saturation is most easily described NOT in terms of input optical signal but in terms of output electrical signal. For example,for the model PD-10.6-3, we expect output saturation at about 10 millivolts for a CW signal, and at about 600 millivolts for asingle short pulse. These represent the extreme cases. Since few if any users have oscilloscopes that will display a signal of 10millivolts with much deflection on the CRT, those users trying to see a CW signal will pretty much always need a preamp.However, users whose input signals are short and strong (say < 1 µsec and > 5 watts peak) should be able to dispense with theamplifier and go direct to the scope using the PD-10.6-3. A certain amount of experimentation around these levels to optimizethem should be expected.Many users in fact have input waveforms that can be considered neither CW nor “short single shot” pulses. This gets us intothe intermediate “quasi-CW” regime. There are no firm rules here, but some guidance is available from experience:• Many CO 2 lasers are called “pulsed” but are in fact better described as modulated. Duty cycle is in the range of 50%and the modulation frequency is in the kHz region. These should be considered CW sources and a preamp used.• Pulsed lasers with short pulses and duty cycles
Boston Electronics Corporation91 Boylston Street, Brookline, Massachusetts 02445 USA(800)347-5445 or (617)566-3821 fax (617)731-0935www.boselec.comboselec@boselec.comOptions for mounting and powering / controlling aVigo thermoelectrically cooled <strong>IR</strong> detector:There are two possibilities; either the user makes his own mount for the detector or he uses theVigo DR-style mount.1. Choose the Vigo DR-style “Lab Bench” mount ONLY if (A) it is not too large as-is forthe space it will be used and (B) only if operation at a fixed stable temperature isrequired.2. Choose to do it yourself if the Vigo DR-style mount does not fit the space available or ifyou need to squeeze out the highest sensitivity at any given ambient temperature(maximize delta-T) rather using than a stabilized temperature set point.Do it yourself:The sketch on the following page illustrates an acceptable self fabricated heat sink and how tomount the detector on it.If you make your own heat sink you will also need to supply your own power and controlelectronics for the thermoelectric cooler. The model PID1500 TE cooler controller fromWavelength Electronics (also available from Boston Electronics) is suitable as are other similardevices. Excellent external preamps, AC-coupled to 500 MHz and DC-coupled to 200 MHz aredescribed in a following page. Also external versions of the internal heat sink enclosed preampfrom Vigo are available as external devices and often can be delivered faster than the formerline.Use our Lab Bench Mount:Our Lab Bench Mount consists of a cylindrical heat sink on a stalk with a weighted base. Thereis room inside the heat sink for a preamplifier and we offer a full range of preamps internal to theheat sink. Or the user can use an external preamp. Finally two choices of cooler controller areoffered, one with +/-1C temperature stability (corresponding to ~2.5% stability of detectoroutput) and the other with +/-0.1C temperature stability for ~0.25% output stability.Sketches with dimensions and with details of the available preamps and controllers are attached.
Page 2 and 3: SPECIFICATION @ 20ºCCHARACTERISTIC
Page 4 and 5: SERIES PVMI-2TE8-12 µm IR PHOTOVOL
Page 7: SPECIFICATION @ 20ºCCHARACTERISTIC
Page 11 and 12: Boston Electronics Corporation91 Bo
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Page 15 and 16: IR Measuring SetFig.7. Detector in
Page 17 and 18: IR Measuring SetFig.17 Pin Assignme
Page 19 and 20: IR Measuring Setwith BNC connectors
Page 21 and 22: IR Measuring Set4.2.1. Appearance a
Page 23 and 24: DIMENSIONSThe detector is followed
Page 25 and 26: VIGO System S.A.Packages with BNC C
Page 27 and 28: VIGO System S.A.Custom EngineeringV
Page 29 and 30: VIGO System S.A.Mechanical Accessor
Page 31: Preamps: achieve detector-noise-lim

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