采用主动条纹偏折和相移技术提出一种新的相位物体波前测量方法。在已标定的摄像机系统中,通过相移和移动条纹显示屏可精确测量相位物体引起的成像光线偏折,从光线偏折分布中提取波前梯度分布,进而计算出待测波前分布。首先在液晶显示屏上分别显示水平和垂直两个方向的正弦灰度调制条纹图,用CCD分别记录下原始条纹图和经过待测物体后的变形条纹图,然后移动液晶显示屏,再次记录下相应的条纹图,可计算出透明相位物体引起的偏折角及其波前分布。通过对正透镜的实际测量,证明了该方法切实可行。

A new wavefront measurement was proposed, which was based on active deflectormetry and phase-shift technique. The deflection of imaging rays caused by a phase object could be measured accurately with the phase-shift technique and a removable screen displaying the horizontal and vertical sinusoidal intensity patterns respectively, and then the wavefront distribution could be calculated after extracting the gradients from the deflection. When a phase object was placed between a screen and a calibrated charge coupled device (CCD) camera, the intensity patterns would be distorted. The distortion distribution can be measured, and another different distortion distribution can be got by moving the screen. Therefore the ray deflection and the wavefront can be obtained. The experimental results of a positive lens had confirmed the feasibility of this method.