ABSOLUTE SPECTRAL RESPONSE CALIBRATION OF A PHOTODETECTOR USING A SPECTRALLY FLAT DETECTOR AND A SELF-CALIBRATED SILICON PHOTODIODE

In this communication we describe the absolute spectral response calibration of a photodetector by a method which extends the spectral range of the silicon photodiode self-calibration technique. The self-calibration of a photodiode was performed at the 632.8 nm HeNe laser line and then used to calibration the absolute response of a spectrally flat thermal detector (ECPR). The other characteristics of the thermal detector that are important to this experiment and which we measured are: linearity, uniformity and window transmittance. The thermal experiment was then used to measure the absolute spectral response of a photodetector (DRTIP) in the 350 to 1000 nm wavelength range using a monochromator and a xenon arc as the tunable source. Comparison with previous measurements of this detector's absolute spectral response in the 400 to 800 nm range showed an average difference of -0.1 +/- 0.6%.