说明：  剪切量测量方法，用于测量检测剪切镜的剪切量，很不错的方法，我查找了大量文献才找到的，如果大家有更好的方法，可以和我分享哦
(Shear measurement method for measuring the shear volume of detection of shear mirror, it is a good way, I find a great deal of literature to find, if you have a better way, you can share with me oh)