Liquid crystal spatial light modulators (LC-SLMs) are devices that can accurately adjust the parameters of beam amplitude, phase, wavefront and polarization. However, due to the limitation of laser damage resistance of component materials, LC-SLMs still have difficulty meeting the application and development needs of a high-average power laser system. Here, we proposed an optically addressable spatial light modulator (OASLM) based on a sapphire substrate. Due to the good thermal conductivity of sapphire, the laser damage resistance of the device was greatly improved. The thermal distribution of OASLM based on the sapphire substrate and the K9 substrate is analyzed by a laser-induced temperature rise model. The experimental results also show the excellent performance of sapphire OASLM under high-power CW laser irradiation, its laser power density is increased from 10 W/cm² to 75 W/cm², and the working time is more than 30 min. By bonding sapphire to the other side, the laser power density can be increased to 100 W/cm², and these are completed without active heat dissipation. This method provides a feasible path for high-average-power SLMs.

In this paper, we propose a fast interference spectral imaging system based on liquid crystal (LC) relaxation. The path delay of nematic LC during falling relaxation is used for the scanning of the optical path. Hyperspectral data can be obtained by Fourier transforming the data according to the path delay. The system can obtain two-dimensional spatial images of arbitrary wavelengths in the range of 300–1100 nm with a spectral resolution of 262 cm⁻¹. Compared with conventional Fourier transform spectroscopy, the system can easily collect and integrate all valid information within 20 s. Based on the LC, controlling the optical path difference between two orthogonally polarized beams can avoid mechanical movement. Finally, the potential for application in contactless and rapid non-destructive optical component defect inspection is demonstrated.