基于相移和非相干成像的反射镜面形测量方法

提出一种新的反射镜面形测量方法。这种方法采用非相干成像和相移技术，CCD摄像机经待测反射镜和相同位置处参考平面镜分别对由计算机产生的正弦光栅进行成像，通过相移技术得到各自的相位分布，从而计算出正弦光栅的相位变化。推导了相位变化与待测反射镜面形梯度的对应关系，提出分别对反射镜进行水平和垂直2个方向光栅相位测量，通过计算可得到梯度分布，由此重建待测反射镜面形。测量中，光栅由计算机产生，可以实现精确的相移，而且可以方便地调节光栅的周期以及方向。计算机模拟和实验表明这一技术的可行性。与传统的干涉计量相比较，这种方法具有结构简单、成本低和灵活性高等优点，特别适用于非球面反射镜和波前变化范围较大的反射镜面形测量。

Shape Measurement for Reflector Based on Phase-shift and Incoherent Imaging

A new technique for shape measurement of reflector was presented. This technique is based on incoherent imaging and phase-shift. COD camera was used to record images of sinusoid fringe pattern, which is generated by computer, displayed on computer monitor and reflected respectively by two objects named as reflector tested and reference mirror. The phase distortion caused by reflector tested can be worked out after measuring phase distribution of two objects by phase shift. The relations between the distortion and the gradients of the shape of reflector tested were derived. By figuring out the gradients, the shape tested can be restructured. This setup also leads a possibility of accurate phase shift and convenience to adjust period and direction of fringe pattern. The stimulation and experiment prove this possibility. Compared with other interference measurements, the method is cheaper,simpler and more flexible. Particularly it may do well in measuring the shape of aspheric reflector and sharp variant reflector.