Spectral characterization of Ge trap detectors and photodiodes used as transfer standards

This paper presents results of investigations of the radiant power spectral responsivity within the near-infrared spectral range. Large-area windowless Ge photodiodes 10 mm in diameter used as single photodiodes, as well as in a trap configuration, were studied within a wide spectral range. The spectral responsivity of the reflection trap detector equipped with three photodiodes is compared with that of a single Ge photodiode from 600 nm to 2000 nm (all photodiodes of the same type). The temperature effect on the spectral responsivity is shown within the temperature range from 10 degreesC to 30 degreesC. The results are discussed in terms of spectral quantum efficiency. Effects of non-linearity are also discussed.