光纤光栅光谱分光解调与接入光纤芯径相关性分析  

Fiber grating spectral spectral demodulation and access fiber core diameter correlation analysis

作　　者：邢宇航 李红[1,2] 孙广开[1,2] 胡林聪 祝连庆[1,2,3] Xing Yuhang;Li Hong;Sun Guangkai;Hu Lincong;Zhu Lianqing(Key Laboratory of Optoelectronic Test Technology and Instrumentation,Ministry of Education,Beijing University of Information Science and Technology,Beijing 100016,China;Beijing Laboratory of Optical Fiber Sensing and System,Beijing Information Science&Technology University,Beijing 100016,China;Guangzhou Nansha Intelligent Photonic Sensing Research Institute,Guangzhou 511462,China)

机构地区：[1]北京信息科技大学仪器科学与光电工程学院光电测试技术及仪器教育部重点实验室,北京100016 [2]北京信息科技大学光纤传感与系统北京实验室,北京100016 [3]广州南沙光子感知技术研究院,广州511462

出　　处：《仪器仪表学报》2025年第1期54-64,共11页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金项目(52375524);北京学者计划研究项目(BJXZ2021-012-00046)资助。

摘　　要：面向细芯光纤光栅传感应用,针对接入光纤芯径不适配所引起的光学成像分辨率较低、光能损失较大、成像质量较差的问题,本文以双光栅二次色散解调光学系统为模型,对比分析了常规单模光纤与不同规格芯径细芯光纤分别接入分光光谱解调模块时对成像和解调精度的影响,模拟了系统成像光斑分辨率、光束发散角、接收面辐照度和MTF曲线在截止频率处取值的变化情况。计算结果表明,当光纤芯径从8μm减小至2μm时,分辨率从0.8 nm提升到0.1 nm。接收面辐照度随芯径值缩小逐渐提升,芯径小于4.8μm后接收面光能利用率达到极限74.98%,曝光时间缩减为常规状态下0.36倍。MTF曲线在截止频率处取值与芯径值呈抛物线相关,芯径取4.2μm时图像接近衍射极限。本文提出并验证了光纤芯径与分光光谱解调成像指标的相关关系,为不同芯径光纤光栅传感的解调技术提供了参考和借鉴。This paper investigates the impact of fiber core diameter on thin-core fiber grating sensing applications,addressing challenges such as low optical imaging resolution,high light energy loss,and poor imaging quality caused by core diameter mismatches in access fibers.Using a dual-grating quadratic dispersion demodulation optical system as a model,a comparative analysis was conducted between conventional single-mode fibers and thin-core fibers with varying core diameters.The study examined the effects on imaging and demodulation accuracy by simulating changes in imaging spot resolution,beam divergence angle,receiving surface irradiance,and the modulation transfer function(MTF)curve at the cutoff frequency.The computational results reveal that reducing the fiber core diameter from 8μm to 2μm improves resolution from 0.8 nm to 0.1 nm and increases irradiance on the receiving surface.The optical energy utilization on the receiving surface reaches its maximum of 74.98%when the core diameter is below 4.8μm,and the exposure time decreases to 36%of the conventional state.Additionally,the MTF curves at the cutoff frequency show a parabolic correlation with core diameter,with images approaching the diffraction limit when the core diameter is 4.2μm.This study establishes and validates the correlation between fiber core diameter and spectral demodulation imaging indices,offering valuable insights and references for fiber grating sensing demodulation technologies with different core diameters.For the thin-core fiber grating sensing applications,for the access fiber core diameter mismatch caused by the optical imaging resolution is low,the loss of light energy is large,the imaging quality is poor.This paper takes the dual grating quadratic dispersion demodulation optical system as a model.Comparative analysis of conventional single-mode fiber and different specifications of the core diameter of the fine-core fiber were accessed spectral demodulation module on the impact of imaging and demodulation accuracy.The changes of th

关 键 词：光纤光栅传感 解调光谱仪 解调 细芯光纤 

分 类 号：TH74[机械工程—光学工程]