全光型激光微片高灵敏度压强传感器

All-optical High Sensitivity Pressure Sensor with Microchip Laser

提出并实现了一种新型全光型压强传感器。用LD输出光经光纤抽运圆片状Nd∶YAG微片 ,被测压强通过传递膜片加到晶体径向上。由于应力双折射效应 ,此微片激光器输出光的频率发生分裂。输出的频率分裂激光经光纤传输至光电接收器 ,其拍频经光电转化成正弦频率电信号 ,探测该频差即可得到被测压强。对此激光器的出光模式对测量的影响进行了研究。实验获得了 1.31MHz/kPa的测量灵敏度。证明此压强传感器适于高灵敏度测量 。

This paper proposed and realized a novel all-optical pressure sensor. It is achieved by using fiber-coupling laser diode (LD) to pump the Nd:YAG microchip. The pressure was imposed indirectly on the radial direction of the crystal by a pressure-transferring device. As a result of the stress birefringence the microchip laser's longitudinal mode was split into two with different frequency. The frequency splitting signal is coupled into fiber, detected by a photodiode and than changed as a detectable beat frequency signal. There is a direct proportional relation between the frequency difference and the pressure imposed on the microchip, so pressure can be obtained. Moreover, the effect of the modes on the measurement error was finished. A result of 1.31 MHz/kPa was achieved in the experiment, so it can be used in the high sensitivity measurement and has a broad application future.