介绍了波片的相位延迟量随温度的变化行为,并提出一种测量相位延迟量的方法。由于温度的变化会对波片的相位延迟量产生影响,从而影响波片的使用精确度,为减小此影响,提高波片在不同温度下的使用精确度,需要对波片的特性进行分析。理论和数值地分析了石英波片的温度特性,得到石英波片的折射率温度系数和热膨胀系数的关系及折射率温度系数与波长的关系,为正确设计和使用波片提供参数选择依据。一块厚约1.8 mm的波片,对应波长632.8 nm,温度每升高1 ℃,其延迟量约减少1°。针对石英波片在不同温度下使用时的不足之处,提出一种测量方法(即电光调制法)用来测量波片的相位延迟量,当信号电压控制在±700 V时,其延迟测量精度可控制在1%以内。

The variation behavior of phase retardation of wave-plate with temperature was introduced, and the electro-optic modulation method was put forward to measure the phase retardation. The variation of temperature has an effect on the phase retardation, thus influencing the useful precision of wave-plate. In order to reduce this negative effect and improve the precision under different temperature conditions, the properties of the wave-plate should be analyzed. The temperature properties were analyzed theoretically and mathematically, then relationship between coefficient of thermal expansion and temperature coefficient of refractive index was obtained. The relationship between temperature coefficient of refractive index and wavelength offered theoretical basis and parameter choice basis for correctly using and designing wave-plate, respectively. The retardation would reduce 1° when the temperature increased 1 ℃ for the wave-plate with thickness of 1.8 mm and wavelength of 632.8 nm. According to the application shortage of wave-plate in different temperatures, the electro-optic modulation method was presented to measure the phase retardation, if the voltage was controlled within the range of ±700 V, the precision of measuring would be within 1%.