Research on precision alignment method of a five-mirror optical derotator system

Abstract

A five-mirror optical derotator system is used in the Accurate Infrared Magnetic System solar telescope by virtue of its polarization-free and superior real-time performance. The derotator system can compensate image rotation during tracking observation. The system consists of five flat mirrors with their normal vectors noncoplanar. Due to the complicated spatial positions of mirrors, it is challenging to align the system with high accuracy. We analyze parallelism and concentricity characteristic of derotator system by matrix transformation and propose a compensation alignment method from multivariables perturbation simulation. This method reduces degrees of freedom for alignment from 10 to 4, which greatly simplifies the installation and adjustment process. Based on the above simulation, the alignment experiment has been conducted successfully with the parallelism and concentricity meeting the requirements. Through theoretical analysis and experimental verification, the proposed method is reasonable and provides an efficient alignment solution for this kind of five-mirror optical derotator system.

Optical axis consistency alignment method for 1m-diameter solar telescope

“…A derotator system is used to eliminate image rotation during solar tracking for the telescope. For the derotator system, a customized reference is fixed representing its optical axis [11] . By adjusting the tilt of the whole derotator system, it is ensured that the self-collimated image of the customized reference coincides with the self-collimated image of the yaw axis reference.…”

Optical alignment technology for 1-meter accurate infrared magnetic system telescope

“…The system consists of five flat mirrors with its specific working principle and alignment method referred to the article. 16 The schematic diagram of the derotator system is indicated in Fig. 35.…”

“…In this situation, it is coaxial with the outgoing light when the system rotated to an arbitrary position. The system consists of five flat mirrors with its specific working principle and alignment method referred to the article 16 . The schematic diagram of the derotator system is indicated in Fig.…”