Author Affiliations
Abstract
1 State Key Laboratory of Dynamic Measurement Technology, North University of China, Taiyuan 030051, China
2 School of Information & Communication Engineering, North University of China, Taiyuan 030051, China
3 School of Instrument & Electronics, North University of China, Taiyuan 030051, China
Sensors based on optical resonators often have their measurement range limited by their cavity linewidth, particularly in the measurement of time-varying signals. This paper introduces a method for optical frequency shift detection using multiple harmonics to expand the dynamic range of sensors based on optical resonators. The proposed method expands the measurement range of optical frequency shift beyond the cavity linewidth while maintaining measurement accuracy. The theoretical derivation of this method is carried out based on the equation of motion for an optical resonator and the recursive relationship of the Bessel function. Experimental results show that the dynamic range is expanded to 4 times greater than the conventional first harmonic method while still maintaining accuracy. Furthermore, we present an objective analysis of the correlation between the expansion factor of the method and the linewidth and free spectrum of the optical resonator.
optical resonator optical frequency shift multiple harmonics dynamic range expansion Chinese Optics Letters
2024, 22(4): 041201
1 中北大学信息与通信工程学院，山西 太原 030051
2 中北大学半导体与物理学院，山西 太原 030051
3 中北大学仪器与电子学院，山西 太原 030051
光功率分配器作为光子集成电路中分束并束的关键器件，要求结构紧凑、宽带、低损耗。基于亚波长光栅（SWG）结构，提出一种分束区域长5 µm、分光比为50∶50的超大带宽低损耗3 dB光功率分配器。仿真结果表明，该光功率分配器在±15 nm的大工艺容差下，TE模式在1.26~2.02 μm波段内（即760 nm带宽）损耗低于0.54 dB。通过电子束曝光、干法刻蚀等工艺在绝缘体上硅（SOI）晶圆上加工制备该光功率分配器，在扫描电子显微镜（SEM）下观察SWG结构的加工误差不超过±10 nm。此外，搭建垂直耦合测试平台，利用可调谐激光器在1496.8~1600 nm波段，对TE模式的损耗与分光比进行测试。结果表明，该波段损耗约为0.3 dB，与仿真结果吻合，分光比误差在5%以内。该功率分配器适用于高速、大容量通信、波分复用（WDM）系统等互联应用场合。
紧凑 宽带 低损耗 光功率分配器 光学学报
2023, 43(22): 2223001
1 中北大学量子传感与精密测量仪器山西省重点实验室, 山西 太原 030051
2 中北大学省部共建动态测试技术国家重点实验室, 山西 太原 030051
基于二维材料的纳机电谐振器具有体积小、频率高、品质因数高等优势,在传感领域具有很大的应用潜力。其中,黑磷由于其波纹状的平面结构和各向异性的机械特性,为平面内矢量传感提供了可能。利用黑磷设计了一种光学激发光学读出的新型纳光机电磁矢量传感器。利用有限元分析法,探究了黑磷层数和长宽比对矢量性的影响,确定了黑磷谐振器的尺寸为0.6 μm×0.134 μm×0.5 nm;分别探索了高杨氏模量和低杨氏模量方向对磁场响应的各向异性。通过谐振模式的空间分布,解释了角度和长宽比对器件灵敏度和矢量性的影响机理。结果表明,将磁场旋转90°,灵敏度可从-4.048 MHz/mT变化为5.796 MHz/mT。与精度相近的洛伦兹力的微机电磁传感器相比,所设计传感器的频率可提高6个数量级,尺寸可缩小6个数量级。该设计为新型纳光机电矢量传感器的制备提供了一种方法。
测量 纳光机电谐振器 黑磷 光驱动 磁矢量
Author Affiliations
Abstract
1 Academy for Advanced Interdisciplinary Research, North University of China, Taiyuan 030051, China
2 School of Instrument and Electronics, North University of China, Taiyuan 030051, China
3 State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
4 School of Information and Communication Engineering, North University of China, Taiyuan 030051, China
Based on the transverse second-harmonic generation (TSHG) effect, we demonstrate a method for in-situ modal inspection of nonlinear micro/nanowaveguides. Pumping lights are equally split and coupled into two ends of a single CdS nanobelt (NB). As pumping light counter-propagates along the NB, transverse second-harmonic (TSH) interference patterns are observed. The influence of multimode interaction on the TSHG effect is discussed in detail. Using fast Fourier transform, TSH interference patterns are analyzed, indicating the existence of at least four modes inside the NB. Experimental beat lengths are found to be in agreement with calculated results.
micro/nanowaveguides transverse second-harmonic generation multimode interference modal inspection Chinese Optics Letters
2021, 19(7): 071901
