由于非共光路误差是菲索干涉仪进行高精度检测中最重要的误差因素之一,而非共光路误差是由于非理想的光学系统即干涉仪的出射波前不理想造成的,所以为了测量干涉仪的出射波前来评估干涉仪非共光路误差的大小,提出一种利用干涉仪猫眼位置绝对测量干涉仪出射波前的方法。该方法基于干涉仪自身的面形测量功能,操作非常简单,只需要一块反射镜就能够实现干涉仪出射波前的测量。该方法通过至少三个猫眼位置的测量得到干涉仪出射波前的自身剪切数据,然后通过基于旋转平移的绝对检测算法直接得到干涉仪的出射波前的二维波前数据。实验结果表明:该方面能够实现不包括Power在内均方根(RMS)值约为15 nm的测量精度。该方法能够准确测量干涉仪出射波前,从而评估干涉仪非共光路误差。 Because the non-common-path error is one of the most important error factors in the high-precision detection of the FESO interferometer, the non-common-path error is caused by the non-ideal optical system that is not ideal for the exit wavefront of the interferometer. Therefore, Interferometer output wavefront to assess the interferometer non-common-path error size, put forward a method using interferometer cat’s eye absolute measurement interferometer exit wavefront. The method is based on the interferometer’s own shape measurement function. The operation is very simple. Only one mirror is needed to measure the wavefront of the interferometer. The method obtains the self-shear data of the exit wavefront of the interferometer through the measurement of at least three cat’s eye positions, and then obtains the two-dimensional wavefront data of the exit wavefront of the interferometer directly by the absolute detection algorithm based on rotational translation. The experimental results show that this method can achieve the measurement accuracy of about 15 nm with no RMS value including Power. This method can accurately measure the interferometer exit wavefront and thus evaluate the interferometer non-common-path error.