任意球面元件的超高反射率测量方法

Super-high reflectivity measurement of arbitrary spheric optical element

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。

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 ana- lyzed 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 dis- cussed separately. The results expand the super-high reflectivity measurement scope of optical elements for the cavity ring-down method.