空间激光通信中发射波面质量接近衍射极限, 测量波面是调整和检验发射系统的依据。传统的平板剪切干涉仪是测量波面的有效手段之一, 但应用在测量波面高度小于0.3个波长, 口径100～300 mm, 短相干长度的半导体激光器时存在一些限制。大口径横向双剪切激光干涉仪改进于马赫曾德尔结构, 可以实现这一功能。干涉仪主要由两块透射反射镜和四块反射镜组成, 其中一块反射镜结构上下分开, 形成一定的夹角, 通过干涉图上下条纹的差分求出波像差, 提高灵敏度。目前建成的仪器有效通光口径为290 mm, 等光程相干涉, 可适用于相干长度短的光源。仪器对可调谐激光器发射波面进行了测量, 通过计算机处理得到波面, 波面高度的峰谷值为1.0个波长。

Laser transmitting wavefront is near diffraction-limited in space laser communication. Wavefront measurement is the basis of system adjustment and testing. Optical plate interferometer is a traditional valid method for wavefront sensing but it is invalid to meet the needs of measuring the wavefront of wave height less than 0.3 wavelength, aperture over 100 mm and laser diode coherence length short. Lateral double shearing laser interferometer is designed based on Maeh-Zehnder interferometer for the application. It includes two plane lens and four mirrors with one of which is vertically divided into two parts. The two parts turn around vertical line oppositely to be a small angle of several seconds between them. The wavefront aberration can be differentially analyzed from the fringes of the two parts and the accuracy is improved. The interferometer of 290 mm diameter suited for short-coherence laser is developed. Optical paths of the interference are equal length that is useful for laser diode etc. The wavefront of a tuning laser is measured by the interferometer. The experimental interferograms are analyzed with the software. The value of the wave height (PV) is 1.0 wavelength.