The night glows brighter in the near-IR

Spectral irradiance, caused by airglow, is several times stronger in the 900-to1700-nm band than in the visible realm. The most natural image still is an intensified image in the visible spectrum and in the near-IR realm, although it is very specular because of the low quantity of incident photons. Short-wavelength infrared (SWIR) delivers very similar images but a larger amount of incident photons. The sensor material for SWIR lowlight-level cameras must offer high quantum efficiency (QE) in the near-IR range. For this purpose, InGaAs is an optimal material because its QE in the 0.9- to 1.65-μm range exceeds 80 percent. Noise generation of the sensor array and its readout circuitry must be kept as low as possible. The self-contained camera core consists of the basic core plus a power conditioning unit and a communications module, which governs two data transmission protocols: GigE Vision and CameraLink.