温度对四频差动激光陀螺零偏的影响机理

Mechanism of temperature’s effect on differential laser gyro bias

讨论了四频差动激光陀螺温变零偏的产生机理,分析了四频差动激光陀螺工作时的热源及其对陀螺在不同工作阶段的影响,实验证明了温度变化时和频和差频的强烈相关性;通过实验分析了陀螺各部分温度变化对和频和零偏的影响,研究了水晶片在温度变化时的物理性质变化,并定量计算了由其产生的广义法拉第偏频、顺逆时针偏振光差损和左右旋偏振光差损的变化对温变零偏的影响大小,结果表明:顺逆时针偏振光差损和左右旋偏振光差损对和频、差频的不同作用机理使得和频与差频的相关性变差,导致采用以和频为基准对陀螺差频进行补偿的方法具有一定的局限性,从而提出了提高以和频为基准的温补精度的措施。

The mechanism of generating thermal bias in differential laser gyro was discussed. Thermal source of differential laser gyro and their influence at different stage were analyzed. Through experiments, strong correlation between frequency sum and frequency difference was proved, and the effect of laser gyro’s different parts on frequency sum and thermal bias was analyzed. The effects of crystal on the thermal bias have been studied with quantities outputs, including the so-called Faraday bias, loss difference between clockwise and counterclockwise laser beams, and loss difference between levorotatory and dextrogyrate modes. As concluded from the experiment and analysis, the different mechanisms of these two kinds of loss differences have lowered the correlation between frequency sum and beat frequency, which lead to some limitations when using frequency sum as a benchmark to compensate the gyro’s frequency difference. So the measures to improve the accuracy was proposed.