Spectrally invariant detectors are commonly used to interpolate or extrapolate the responsivity of InGaAs detectors in the infrared from absolute calibrations at a few wavelengths. The random noise in such detectors limits the accuracy that can be achieved in a narrowband, double-monochromator setup. We propose the application of a dedicated digital filter, which reduces the uncertainty by 30%, and combine it by calibrating a group of three detectors. The uncertainties are propagated from the observed variance in the relative measurement to the combined uncertainty of 0.4% (2 sigma) in the responsivity values of the InGaAs detectors in the range of 1010-1640 nm.
© 2005 Optical Society of America
(040.3060) Detectors : Infrared
(040.5160) Detectors : Photodetectors
(120.3940) Instrumentation, measurement, and metrology : Metrology
(120.5630) Instrumentation, measurement, and metrology : Radiometry
Jarle Gran, Kristian Ellingsberg, and Aasmund S. Sudbø, "Establishing a high-accuracy spectral response scale in the near infrared with digital filters," Appl. Opt. 44, 2482-2489 (2005)