近红外波段石英晶体旋光率的测试研究

Research on the optical rotatory power of quartz crystal in near-infrared waveband

具有自然旋光性的石英晶体是最重要的光学材料之一。在利用其进行实验研究和设计制作光学元器件时,准确地知道石英晶体在所使用波长下的旋光率是必要条件。目前,还没有资料给出石英晶体在近红外波段的旋光率。设计了利用可调谐激光器和双光路检测方法构成的测试系统,准确地测得了石英晶体在850nm、1310nm和1550nm三个波段的旋光率。利用实验数据求得了Sellmeier方程中的常数,并构建了近红外波段的Sellmeier方程。由该方程给出的旋光色散曲线,在上述3个波段均与实验曲线很好吻合,并与光学手册中1342nm和794nm对应的旋光率完全一致,证明了实验结果的可靠性。实验结果为今后石英晶体在近红外波段的实际应用提供了数据支持。

Quartz crystal with natural optical rotation feature is one of the most important optical materials. When it is used in experimental research or in optical device design and manufacture, it is essential to know the specific rotatory power accurately for the wavelength in use. So far, there is no information relating to the specific rotatory power of quartz crystal at near-infrared waveband. Using tunable laser and double-beam test method, we have designed a measurement system, with which we measured the rotatory power of quartz crystal at three wavebands： 850 nm, 1 310 nm, and 1 550 nm accurately. From the experiment data we also calculated the coefficients in Selimeier equation, and then constructed the Sellmeier equation for near-infrared waveband. Optical rotatory dispersion plots obtained from the constructed equation are well coincide with the experiment results in all the three wavebands, and furthermore the calculated rotatory powers from the equation at 1 342 nm and 794 nm are completely consistent with those in optics handbook, which proves the reliability of our experiment result. Our experiment results provide the data support for the practical application of quartz crystal at near-infrared waveband.