Research Article Realization of the Radiance Scale Using Transfer Function of the Laser-Based Optical System M. Kilin , 1 H. Tutunculer, 1 O. Bazkir, 2 and S. Meric 2 1 Engineering Physics Department, Gaziantep University, 27310 Sehitkamil, Gaziantep, Turkey 2 Optic Laboratory, TUBITAK-National Metrology Institute (UME), 41470 Gebze, Kocaeli, Turkey Correspondence should be addressed to M. Kilin; mkilin@gantep.edu.tr Received 2 August 2019; Revised 14 February 2020; Accepted 6 March 2020; Published 1 April 2020 Academic Editor: Nicusor Iftimia Copyright©2020M.Kilinetal.isisanopenaccessarticledistributedundertheCreativeCommonsAttributionLicense,which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. is work aims to determine the radiance responsivity to be used in the calibration of polychromatic radiation sources with low uncertainty. To realize the radiance, Ar-ion, He-Ne, and Nd-YAG lasers as well as an integrating sphere with a 0.15 m diameter are used to obtain radiation sources having Lambertian distributions. en, a silicon photodiode-based reflection-type trap detector with calibrated precision aperture, which is traceable to a liquid helium cooled laser-based cryogenic radiometer, is used to measure the photocurrent corresponding to each wavelength and thereby to obtain radiance. e proposed system, which measures the spectral current response of this laser-based radiance, is a double-grating monochromator with a 2 × 300 mm focal length and triple gratings in each of its turrets. First, the radiance of the laser beam that emerged from the integrating sphere is calculated, and then the radiance responsivity of the system is obtained by measuring the photocurrent outputted from the exit slit of the monochromator at each laser wavelength. Finally, the spectral radiance values of the polychromatic lamps are obtained using the radiance responsivity of the system. Consequently, the study aims to develop the derivation and better understand traceability of the other radiometric and photometric quantities with low uncertainty from the fundamental radiometric radiance unit. Measurement results obtained in the expanded measurement uncertainty scale are determined using both classical and Monte Carlo methods. 1. Introduction In optic radiometry, measurement systems consist of three main components, namely, radiation sources, detectors, and optic and optomechanical materials, which form the basis for the envi- ronment in which they are transferred. e measurement traceability chain for the control of the optical performance of these components can be realized in two different ways, depending on whether they are source or detector based. Source-based measuring chains employ the blackbody radiation principle, are called “black body radiators,” and are formed to be traceable to high-precision systems [1, 2]. Detector-based measuring chains have been formed such that they are traceable to low-temperature radiometry that operates on the principle of electrical substitution of the response of the detectors to optical power at the liquid helium temperature (4.2 K) [3–6]. One of the methods utilized in measurement chains that are developed to realize the radiation scale is to obtain the radiation of the light source compared with that of black body radiator systems. ese radiation measurements are performed at specific temperatures by extending with physical modeling of the spectral radiation data [7–9]. Another alternative measurement method that was devel- oped uses a monochromator system and a sensor that is calibrated against a low-temperature radiometer operating at liquid helium temperature (4.2K) [10, 11]. e second one has a lower uncertainty than the first, but it is within the required resolution range for the measurements; the signal- to-noise ratio (SNR) of the output of the monochromator causes high uncertainty in the transfer function. In recent years, a method that was developed to solve this problem, and which has been used in metrology laboratories, is the use of a laser radiation source instead of a polychromatic Hindawi International Journal of Optics Volume 2020, Article ID 4184360, 10 pages https://doi.org/10.1155/2020/4184360