Design of Photoelastic Modulator Driving Control Module Based on FPGA
With the development of technology,the detection range of optical detection has a greater demand,the use of pho-toelastic modulator instead of the traditional polarization modulator,has a wide spectrum range,high frequency modulation advan-tages.According to the structure of the photoelastic modulator used in the ellipsometer,a control module of the photoelastic modula-tor based on FPGA is designed in this paper.It mainly consists of a driving module and a feedback regulating module.The stable driving control of the photoelastic modulator is realized by using DDS technology and digital phase-lock technology.The test verifies that the module can stably generate driving signals above 60kHz and 450VPP,and the designed driving module can meet the control requirements of photoelastic modulator.