Realization of spectral irradiance responsivity at NIS-Egypt

Realization of the absolute spectral irradiance responsivity of photodetectors in A/W/cm2 is a fundamental requirement for many photometric, radiometric and colorimetric applications. This work aimed to develop a standardized radiometric setup for realizing the absolute spectral irradiance responsivity in the range of 500 nm-950 nm at the National Institute of Standards (NIS), Egypt. A silicon trap detector, calibrated against the primary standard cryogenic radiometer, is used as a transfer standard for the calibration of S2281 Hamamatsu silicon photodiode, as a working standard, using a lamp-double monochromator based system. The accompanied uncertainty components affecting the measurements were investigated.