Investigation of Grating Collimation of Coherent Gradient Sensing Technique
In this paper, the grating collimation of coherent gradient sensing (CGS) technique was investigated. Due to the basic principle of the CGS technique, two gratings are used to obtain the interference fringe pattern, therefore, the accuracy of the CGS technique is directly influenced by the collimation of the two gratings. In order to investigate the grating collimation of the CGS technique, a standard specimen was implemented. The measurement results show that the error becomes larger when the rotational misalignment between the gratings was increased.
KeywordsCollimation Grating Coherent gradient sensing technique Rotational misalignment
This paper was supported in part by the Ministry of Science and Technology (Grant no. MOST 105-2221-E-007-047-MY3), Taiwan, Republic of China.