激光点光源干涉法(如图1所示),是将激光器1发出的高斯光束经光学系统2聚焦变成点光源S,从S发出的球面波经平行平板4的两测量面反射后相遇发生干涉,其干涉性质为双光束非定域干涉。干涉图样为同心圆环,屏3上所接收的圆环圆心位置随两被测面间的夹角而变。今设夹角为α,圆心偏离点光源为r_(?),分别推导其计算公式。 Laser point light source interference method (shown in Figure 1), the laser 1 is emitted by the Gaussian beam focused by the optical system 2 into a point light source S, the spherical wave emitted from S reflected by the two parallel plane 4 measuring surface meet Interference, the interference nature of the two-beam non-local interference. The interference pattern is a concentric ring. The position of the center of the circle received on the screen 3 varies with the angle between two measured surfaces. Suppose the included angle is α, the center of the circle deviates from the point light source is r_ (?), Deduces its calculation formula respectively.