Investigation of spectral radiance responsivity for optical systems

The aim of this thesis is establishment and determination of radiance responsivity to be used in calibrations of polychromatic radiation sources. In realizing the radiance, Ar-Ion (457, 477,488 and 514 nm), He-Ne (543, 594, 604, 612 and 632.8 nm) and Nd:YAG (532 nm,1064 nm) lasers and an integrating sphere with 15 cm diameter are used to get radiation sources having Lambertian distributions. Then silicon photodiode based trap detector which is treaceble to the liquid helium cooled laser based cryogenic radiometer is used to measure the photocurrent corresponding to each wavelength and thereby to obtain radiance. The measurement system used to have spectral current response of this laser based radiance is a double grating monochromator with 2 x 300 mm focal length and triple gratings in its each turrets. The gratings used for these measurements have 2400 g/mm and 1200 g/mm grove densities and blazed to 250 nm and 500 nm respectively. The laser beams emerged from the integrating sphere after the radiance evaluation directed on monochromator and from its exit slit the photocurrent responses record at each laser wavelengths. From the radiance realized at laser wavelengths and the photocurrent, values recorded at the exit slit of monochromator, transfer function (radiance responsivity) of the optical system is obtained. This radiance responsivity together with monochromator system is used to derive the spectral radiance of polychromatic radiation sources with low uncertainty. Moreover, in this work the uncertainty scale is determined using both classical and Monte Carlo methods.