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Cooling
In many cases IR detectors are cooled during use. This cooling effects the spectral response, responsivity and response speed. Spectral response characteristics of PbS, PbSe, and HgCdTe (MCT) shift to the long wavelength side with cooling while Ge, InAs and InSb shift to the short wavelength side. Also, note that the response speeds of PbS and PbSe become slower with cooling. Methods of cooling include thermoelectric cooling and dewar cooling using dry ice, liquid nitrogen, etc.
Thermoelectric cooled detector systems include:

1. Detector head with integral amplifier, Peltier cooler, temperature sensor.
2. Temperature control unit with integral power supply.
Nitrogen cooled detector systems include:
Detector head with integral amplifier mounted in dewar.
Options Available
1. Mount adapters for all Sciencetech monochromators.
2. Computer data acquisition board A/D for use with PC compatible computer.
Standard 12 bit and DC up to 110 KHz frequency. Others available upon request.
GE Detectors 0.8 - 1.8 Microns
Germanium photodiode detectors are designed for operation in the 0.8 to 1.8 µm range. Included are state-of-the-art detector components, detector/amplifier hybrids, TE cooled and cryogenically cooled modules.
Standard active areas (mm):
0.1 dia 0.3 dia 1.0 dia 2.0 dia
3.0 dia 5.0 dia 10 x 10

GELN-50. Ge detector in liquid N2 dewar with integral preamplifier
- Spectral range 800-1500 nm @ 77 K
- Active area: 5mm
- Operating temperature: 77K.
- Responsivity 0.80 A/W minimum, 0.9 A/W typical
- NEP < 1.5 x 10-15 W/Hz1/2 @ 77 K
- Shunt Resistance 10 K Ohm @ 298 K; > 1000 M Ohm @ 77 K
- Shunt Capacitance 30000 pF typical
- Dewar type: metal, side view.
- Dewar holding time: 10 hours.
- Dewar size: 6.75" height, 2.5" diameter. Height (from the bottom) of the detector window: 1.45"
- Field of View: 60 degrees nominal
- Amplifier Dual-Gain Transimpedance
- Bandwidth DC-15 Hz/ DC- 150 Hz
Indium Gallium Arsenide Detectors, 0.9 - 1.7 Microns (InGaAs)
Standard InGaAs photodiode detectors are designed for operation in the 0.8 to 1.7 µm spectral range.
Included are state-of-the-art detector components, detector/amplifier hybrids, TE cooled and cryogenically cooled modules. These units offer better performance than germanium detectors.
Standard active areas (mm):
0.1 dia 0.3 dia 1.0 dia 2.0 dia 3.0 dia

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