SAW陀螺效应声光衍射角度及其微小变化的CCD检测系统

摘要

A deflection angle of acoustooptical Bragg diffraction on an acoustic-optical medium is modulated by ultrasonic, and on the other hand, surface acoustic wave (SAW) propagation velocity can be influenced by rotational velocity Ω of SAW medium. Therefore, the Ω can be figured out according to measuring the Bragg diffractive angle. However, the diffracted angle and its variation due to SAW gyroscopic effect is very tiny (arcmin and arcsec level), so the key to the plan is whether such a tiny Bragg diffractive angle can be measured with success. After introducing SAW gyroscopic effect and acoustooptical Bragg diffraction effect briefly, a measuring tiny angle plan with CCD is put forward. Some core technology to measure tiny angle are discussed.%声表面波(SAW)陀螺效应表现为SAW介质旋转角速度Ω对SAW波速的调制作用,以及对布拉格衍射角的调制作用.因此,通过测量声光布拉格衍射光的偏转角度,可以反推被测SAW介质的旋转角速度Ω.理论计算表明布拉格衍射角及其变化十分微小(弧分、秒数量级),所以能否在实践中成功地检测受Ω调制的布拉格衍射角,关系到SAW陀螺效应声光探测和检测方案的成败.在扼要说明了Ω调制布拉格衍射角的物理原理后,初步设计了布拉格衍射角的CCD测量系统并讨论了影响其测角精度的若干关键技术.