Design Of A Grating Diffraction Performance Detection System

When light passes through an optical device or solution,optical phenomena such as reflection,transmission,and scattering are generated.Optical performance detection refers to the detection of these optical phenomena to analyze the physical and chemical properties of the sample to be tested.Diffraction grating is an important optical device,which is composed of micro / sub-micron scale lines.There are multiple diffraction orders of the grating.The angular spacing of each stage is determined by the grating constant,that is,the number of reticles per millimeter.The diffraction efficiency distribution of each stage is mainly determined by the microscopic groove pattern of the grating.The accuracy of the diffraction angle and diffraction efficiency of every level is indispensable for evaluating the performance of the grating.However,unlike the conventional transmission / reflection detection,if the detection is manual,it will cause cumbersome procedures and low accuracy.Therefore,it is of great significance to develop an automated grating performance detection system.Although there already exist some testing devices,component system is usually very complex and the detection efficiency unsatisfying.Thus,this subject aims to design a more simple,convenient and efficient testing system.Focusing on the performance parameters of the grating,this topic puts forward the requirements of the system.Accordingly,we design the optics,electric circuits,and software of the system.Considering the transmission blazed grating as the detection target,we test the diffraction angle and diffraction efficiency of each level and analyze the experimental results compared with the theoretical value.The results show that the detection duration of the system to be measured is less than 3minutes,and the detection accuracy of the diffraction angle reaches 0.2 °,and the detection error of the diffraction angle and diffraction efficiency does is no more than2%,which meets the requirements for the automatic detection of grating performance.