高精度纯相位液晶空间光调制器的研究

Investigation on the Liquid Crystal Spatial Light Modulator with High Precision and Pure Phase

研制了平行排列液晶空间光调制器(LC SLM)。论述了平行排列液晶相位调制的理论,进行了计算模拟。对液晶空间光调制器相位调制特性和振幅调制特性进行了测量,实验结果表明,在整个灰度级范围内是纯相位调制的空间光调制器,并且调制的范围可达到0.6λ。在ZYGO菲佐干涉仪上进行了精度特性的研究,得到了非常好的结果,在1 cm2的面积上,进行了畸变波前的调制,其精度峰谷值可达0.098λ,均方根值可达0.017λ。在此精度的基础上产生了π相位差的栅结构,证明了这种液晶空间光调制器可以很好的进行相位调制。

A liquid crystal spatial light modulator （LC SLM） with parallel alignment TFT is prepared, the theory of which is also discussed. And properties of the modulation are theoretically calculated. Measurements are conducted on properties of the phase modulation and the amptitude modulation. The results indicate that it is a pure phase modulator in the range of the gray level. Its precision is measured on a ZYGO interferometer. The experiments show that on the area of 1 cm× 1 cm the peak to valley （PV） value is up to 0. 098λ, RMS up to 0. 017λ, and the depth of modulation up to 0. 6λ after correction. A grating configuration with the phase differences of π/2 is accordingly generated, which shows that the phase of light can be medulated with it quite well.