Abstract: Disclosed is a radiation detector which includes at least one photoconductive detector and a modulator, which modulates in an on-off manner radiation passing to the photoconductive detector from a radiation source. A bias source is connected to one terminal of the photoconductive detector. A first amplifier is connected to the other terminal of the photoconductive detector, and a second amplifier receives an output of the first amplifier. A first phase detector detects the phase of modulation of the radiation source by the modulator and generates a reference signal relating thereto. A switch in the second amplifier changes, in response to the reference signal generated by the first phase detector, the second amplifier between an inverting state and a non-inverting state as the modulator changes the phase of modulation of the radiation.

Abstract: Disclosed is a radiation detector which includes a photoconductive detector and a modulator which modulates radiation passing to the photoconductive detector from a radiation source. An AC bias source is connected to the photoconductive detector and provides at least two levels of bias thereto. The modulator supplies synchronization signals to the AC bias source such that the level of bias supplied to the photoconductive detector is synchronized to the modulation of the radiation by the modulator. An integrator is connected to and receives an output signal generated by the photoconductive detector.

Abstract: A detector includes a plurality of detector elements in a linear array. A bias source is connected to the input terminal of each detector element. The bias source includes a first bias connected to the input terminals of a first set of detector elements including alternating detector elements and is also connected through an associated measurement device to the output terminals of a second set of detector elements including the remaining detector elements. The bias source also includes a second bias, different from the first bias, and connected through an associated measurement device to the output terminals of the first set of detector elements. The second bias is also connected to the input terminals of the second set of detector elements.

Abstract: A general purpose programmable optical analyzer employs a nonlinear gain at the input stage of an analog to digital converter in order to limit the number of bits used to resolve shot noise.