基于光纤激光频率分裂效应的折射率/厚度双参量测量研究

折射率作为光学系统中应用最广泛的光学参数之一,对系统的光学性能具有极其重要的影响.厚度与折射率所组成的光学长度直接影响双折射器件在光学系统中的时延特性.本文提出一种基于光纤激光频率分裂效应的折射率/厚度双参量测量方法.该系统通过对插入激光腔内的双折射器件进行旋转,利用频率分裂效应对不同角度的器件的双折射参数进行测量.基...

Measurement of refractive index and thickness based on the fiberlaser frequency splitting effect

Refractive index is the most widely used optical parameter in the optical system, which has an extremely important influence onthe optical performance. The optical length consists of refractive index and thickness, which directly affects the time delay characteristicsof birefringent devices in the optical system. In this article, a measurement method of refractive index and thickness based on the fiberlaser frequency splitting effect is proposed. By rotating the birefringent device inserted into the laser cavity, the birefringent parameters ofthe device at different angles are measured by using the frequency splitting effect. Based on the refractive index ellipsoid of birefringentdevice, the relationship among phase delay, refractive index, thickness and rotation angle is established. The refractive index andthickness parameters of the device are achieved by fitting calculation. Experimental results show that the thickness measurement error ofbirefringent elements is 210 nm, and the intrinsic refractive index measurement error is 10-5. It could be widely used in the measurementof intrinsic refractive index and thickness of birefringent elements in the infrared band.