提出了一种可用于四波横向剪切干涉波前检测的随机编码混合光栅。由期望得到的四波前衍射频谱出发，根据夫琅禾费衍射原理并结合光通量约束的随机编码方法得到了由振幅编码光栅和棋盘式相位光栅构成的随机编码混合光栅，与改进的哈特曼模板(MHM)相比，其衍射场中只有四个级次，更好地实现了四波横向剪切干涉。分析确定了入射光束口径、光栅栅距以及观察距离等系统参数。分别给出了随机编码混合光栅和MHM 的远场衍射光场分布及四波横向剪切干涉图，对比发现随机编码混合光栅的远场衍射光场中只有四个等光强的光斑存在，其四波横向剪切干涉图稳定，可以实现任意畸变的波前检测。

A new type of randomly encoded hybrid grating for wavefront testing by quadriwave lateral shearing interferometry is proposed. The randomly encoded hybrid grating which includes an amplitude encoded grating and a phase chessboard is obtained according to the Fraunhofer diffraction principle and the randomly coding method based on the quantization of radiant flux. Compared with the modified Hartmann mask (MHM), only four diffraction orders exist in its diffraction field, and the quadriwave lateral shearing interferometry is better achieved. System parameters such as the incident beam diameter, grating pitch and the distance from the grating to the imaging plane are analyzed and determined. Comparing the far-field intensity distribution and quadriwave lateral shearing interferograms of the randomly encoded hybrid grating with MHM, results show that only four spots with equal intensity exist in the far-field diffraction of the randomly encoded hybrid grating; the shearing interferogram is stable, and it is capable of detecting arbitrary wavefront aberrations.