Wan Yuhang, Cheng Mengxuan, Zheng Zheng, Liu Kai
School of Electronics and Information Engineering, Beihang University, 37 Xueyuan Rd., Beijing 100083, China.
Collaborative Innovation Center of Geospatial Technology, 129 Luoyu Rd., Wuhan 430079, China.
Sensors (Basel). 2019 May 5;19(9):2088. doi: 10.3390/s19092088.
A polarization-modulation-based Goos-Hanchen (GH) sensing scheme leveraging the polarization-dependence of the Bloch surface wave enhanced GH shift is proposed and experimentally demonstrated. Based on a simple setup utilizing a liquid crystal modulator to switch the polarization state of the input beam periodically, the alternating positions of the reflected beam for both polarizations are monitored by a lock-in amplifier to handily retrieve the GH shift signal. The conventional direct measurement of the beam position for the target state of polarization is vulnerable to instabilities in the optomechanical setup and alignment. Our proposed scheme provides a sensitive yet robust GH shift-sensing setup where the common mode drift and noise could be suppressed to ensure better system stability.
提出并通过实验证明了一种基于偏振调制的古斯-汉欣（GH）传感方案，该方案利用布洛赫表面波增强的GH位移的偏振依赖性。基于一个简单的设置，利用液晶调制器周期性地切换输入光束的偏振态，通过锁相放大器监测两种偏振态下反射光束的交替位置，以方便地获取GH位移信号。传统的直接测量目标偏振态下光束位置的方法容易受到光机械装置和对准中的不稳定性影响。我们提出的方案提供了一种灵敏且稳健的GH位移传感装置，其中共模漂移和噪声可以被抑制，以确保更好的系统稳定性。
