Zheng Yichao, Li Jinjian, Liu Yi, Li Yan, Qu Shiliang
Opt Express. 2022 Jan 17;30(2):2288-2298. doi: 10.1364/OE.448088.
We proposed a novel torsion sensor based on the Lyot filter with the twisted polarization-maintaining fiber (PMF) acting as the birefringence medium. Lyot filter is formed by two linear polarizers and a piece of PMF. Based on the high birefringence of the PMF, the output polarization rotates with a rate equal to the twisting rate applied on the PMF, and the sensor realizes a high sensitivity of 90.072 dB/rad. The proposed sensor also demonstrated a low strain sensitivity of 2.32 ×10 rad/μɛ. On the other hand, based on the phase hits of the polarization interference, the wavelength sensitivity reaches 15.477 nm/rad. The monitoring range of the wavelength demodulation is complementary with the intensity demodulation in one cycle, making the valid sensing range of the proposed sensor expand. The proposed highly sensitive compact torsion sensor, with large sensing range and low crosstalk, has potential applications in many fields such as manufacturing industry, civil engineering, aerospace industry and modern smart structure monitoring.
我们提出了一种基于利奥滤光器的新型扭转传感器，其中具有扭曲的保偏光纤（PMF）作为双折射介质。利奥滤光器由两个线性偏振器和一段保偏光纤组成。基于保偏光纤的高双折射特性，输出偏振以与施加在保偏光纤上的扭转速率相等的速率旋转，该传感器实现了90.072 dB/rad的高灵敏度。所提出的传感器还表现出2.32×10⁻⁶ rad/με的低应变灵敏度。另一方面，基于偏振干涉的相位命中，波长灵敏度达到15.477 nm/rad。波长解调的监测范围在一个周期内与强度解调互补，使得所提出的传感器的有效传感范围得以扩展。所提出的高灵敏度紧凑型扭转传感器，具有大的传感范围和低串扰，在制造业、土木工程、航空航天工业和现代智能结构监测等许多领域具有潜在应用。
