基于液晶器件相位补偿的光学玻璃残余应力测量OA

Residual stress in optical glass induces stress-induced birefringence,resulting in phase retardation of polarized light.The phase retardation is an important parameter for quantitative residual stress characterization.To address the instability of phase determination in conventional polarization phase retrieval methods over a large phase retardation range,a polarization imaging measurement method for optical glass residual stress based on liquid crystal device phase compensation is proposed.A liquid crystal device is introduced into the polarization optical path,and the compensation phase is continuously adjusted by the driving voltage to achieve phase matching between the liquid crystal compensation and the phase retardation of the tested optical glass.The difference between the image grayscale and the background grayscale is used as the evaluation metric,and the optimal compensation state is determined by minimizing the grayscale difference,thereby the phase retardation of the optical glass is obtained.The residual stress is then determined based on the stress-optic law.Experimental results show that the optimal compensation state is achieved at a driving voltage of 3.8 V,corresponding to a residual stress of 36.235 nm/cm.Compared with the result obtained using the standard polarization phase retrieval method(34.128 nm/cm),the proposed method exhibits a relative deviation of 6.17%,indicating good consistency between the two results and validating the effectiveness of the proposed method.