探测激光超声用的激光外差干涉仪

^Detection Research of Solid Surface Laser Ultrasonic Pulse Using Laser Heterodyne Interferometric Method

述了用外差干涉法探测固体表面激光超声的原理和实验结果，讨论了信号光、参考光的准直角对信噪比Ｓ／Ｎ的影响和信号光在分束器上的入射角对外差信号强度的影响。理论和实验结果表明：当选择人射角时，可以得到约２倍的外差信号强度。为提高检测信号的强度，提出并讨论了外差干涉的共轭输出法。

The measuring principle and experiment of Laser Ultrasonic Pulse by Laser Heterodyne Interfermetric Method is described. The effect of collimation angle of signal light、 reference light upon S/N radio is discussed, and the effect of incidence of signal light upon bean spliter on heterodyne signal intensity is discussed too. In order to increase the detective signal intensity, the method of heterodyne interferomtric conjugate output is developed.