任意球面元件的超高反射率测量方法

为了实现任意球面元件的超高反射率测量，提出直腔和折叠腔两种光腔结构，以实现0,10,15和30等不同角度下球面元件的超高反射率测量。详细分析了这两种测量方式，根据光束传输变换公式，推导了任意球面元件在测量中引入的衰荡光腔物理腔长的变化，得到了实验测量中腔长调节指导。并根据光腔衰荡法原理，推导了球面元件在超高反射率测量中的通用数学表达式，对测量公式进行了讨论，分析结果扩展了光腔衰荡法在元件超高反射率测量的使用范围。

Super high reflectivity measurement of arbitrary spheric optical element

In order to measure super high reflectivity of any sphere optical element at different angles, such as 0°, 10°, 15°, 30° and so on, two optical resonator structures are put forward: one is straight cavity, and the other is folded cavity. Physical length of the ring down cavity is defined based on the concept of light path. These two kinds of measurement methods are analyzed in detail. When spherical surface is put in the ring down cavity, it brings length misalignment of the ring down cavity. This varied length is derived based on the beam transmission and transformation law, which can be used as length adjustment guidance of the ring down cavity for reflectivity measurement. In addition, according to reflectivity measuring principle of cavity ring down, mathematical expressions of reflectivity measuring for spherical components are deduced at different angles, which are discussed separately. The results expand the super high reflectivity measurement scope of optical elements for the cavity ring down method.