提出Mask相位法校准出厂标定波长在532 nm的液晶空间光调制器(LC-SLM)在561 nm处的相位调制特性曲线。首先基于傅里叶光学模拟计算得出棋盘型二维相位光栅相位对比度与零级衍射光斑光强之间的对应关系，然后搭建实验光路测量计算机所发灰度图所对应的零级衍射光斑光强值。根据前面两组结果最后得到相位延迟量与计算机灰度级之间的关系曲线，从而得到LC-SLM在561 nm处的相位调制特性曲线。用4λ的离焦对光斑进行调制，校准之后光斑光强分布与理论计算值之间的偏差为45.7，比校准之前的偏差110.4减少了64.7；用10λ的倾斜对光斑进行调制，校准之后零级衍射光斑和二级衍射光斑的强度分别是校准前的32.3%和64.1%。实验结果表明，使用Mask相位法对LC-SLM的相位调制特性曲线进行校准之后，LC-SLM的调制效果有了明显的改进。

A Mask-phase method is proposed to calibrate the modulation property of liquid-crystal-spatial light modulator (LC-SLM) at 561 nm, which is calibrated at 532 nm as ex-factory. Firstly, the relation between the phase contrast of the checkerboard phase grating and the intensity of zero-order diffraction spots is simulated based on Fourier optics. Then the optical path is set up to measure the relation between the gray level and the intensity of zero-order diffraction spots. At last the relation between the gray level and the phase retardation is obtained according to the simulation and experimental results. And the phase-modulation characteristic curve of the LC-SLM at 561 nm is also acquired. After calibration, a spot is modulated by 4λ defocus. In this condition, the intensity distribution deviating from the theoretical value is 45.7, and is reduced by 64.7 compared with 110.4, which is the intensity distribution before calibration. When the spot is modulated by 10λ tilt, the intensities of zero-order and second-order after calibration are reduced to 32.3% and 64.1% respectively, compared to the intensity distribution before calibration. Experimental result indicates that the modulation result of LC-SLM has a great improvement after calibration by the Mask-phase method.