Research On Optical Nonuniformity Detection Technology Based On Dual Wavelength Phase Shifting Interference

Optical interference testing technology has high accuracy and high sensitivity, and it is a non-contact measurement method. Two-wavelength phase-shifting interferometry combining two-wavelength holography technique and phase-shifting interferometric technique, has inreplaceable advantages compared to the traditional single-wavelength phase shifting interferometry, such as high accuracy and wide measurement range, so it has a wide range of applications in the field of Metrology.This paper has described the principle of two-wavelength phase-shifting interferometry and the existing two-wavelength interferometer. For the purpose of establishing the experimental device of two-wavelength phase-shifting interferometer, the optical system of two-wavelength phase-shifting interferometer, achromatic collimating lens and imaging lens have been designed. According to the general technical requirements of the device, the relevant hardware parameters have been determined based on the analysis of calculation, and the two-wavelength phase-shifting interferometer alignment has been completed. The operating wavelength of the two-wavelength phase-shifting interferometer are 632.8nm and 532nm respectively, and the test caliber is 100mm. On the basis of studying the traditional four-step measurement of the optical homogeneity of the sample, the two-step measurement methods of the optical homogeneity based on the two-wavelength phase-shifting interferometry has been proposed. This method has the advantages of the simple operation and high accuracy. Computer simulations have verified the validity and feasibility of the method. Finally, the optical homogeneity of the sample has been tested with a Fizeau two-wavelength phase-shifting interferometer. Compared with the test results with ZYGO interferometer, the measuring results are consistent.