Feng Danqi, Tang Yangxu, Liu Yuwei, Deng Ming
Opt Lett. 2023 Aug 15;48(16):4364-4367. doi: 10.1364/OL.495326.
We propose and demonstrate a new, to the best of our knowledge, technique to implement a high-speed and highly sensitive torsion sensor based on a coupled optoelectronic oscillator (COEO) incorporating nonlinear polarization rotation (NPR). The COEO consists of a mode-locked laser loop and an OEO loop. In the laser loop, the NPR effect effectively induces intensity- and wavelength-dependent loss, which acts as a Lyot birefringent fiber filter. When twisting the polarization-maintaining fiber (PMF), the transmission of the filter varies as well as the laser output wavelength. In the OEO loop, the optical source is provided by the output signal of the mode-locked laser. The variation in the optical carrier wavelength changes the time delay and the oscillation frequency of the OEO loop. The oscillation frequency shift is a linear function of the twist angle. Sensitivities of -60.006 Hz/deg over 360° for a 48 cm PMF and -180.996 Hz/deg over 92° for a 22 cm PMF are achieved.
据我们所知，我们提出并演示了一种基于包含非线性偏振旋转（NPR）的耦合光电振荡器（COEO）来实现高速且高灵敏度扭转传感器的新技术。该COEO由一个锁模激光环路和一个光电振荡器环路组成。在激光环路中，NPR效应有效地诱导了强度和波长相关的损耗，其作用类似于利奥滤光器。当扭转保偏光纤（PMF）时，滤波器的传输以及激光输出波长都会发生变化。在光电振荡器环路中，光源由锁模激光的输出信号提供。光载波波长的变化会改变光电振荡器环路的时间延迟和振荡频率。振荡频率偏移是扭转角度的线性函数。对于48厘米的保偏光纤，在360°范围内实现了-60.006 Hz/°的灵敏度；对于22厘米的保偏光纤，在92°范围内实现了-180.996 Hz/°的灵敏度。
