Multi-Axis Parallelism Measuring System With Temperature Insensitivity

In order to detect the parallelism of optical axis of photoelectric device accurately in large temperature difference environment, we design a measuring system based on Cassegrain structure. The system is adapt to the temperature range from -40 degrees C to +55 degrees C with the spectral bandwidth from 0.4 mu m to 12 mu m. According to the demand of temperature stability, the athermal structure of the system is analyzed and the compensation by different mechanical materials is carried out. The beam parallel deviation is less than 4 '' in different temperature. The experimental result shows that the system has good temperature stability.