基于电流内调制DFB激光器的高空间分辨率OFDR  

High Spatial Resolution OFDR Based on In-Current Modulation of DFB Laser

作　　者：张嘉彤 苏丽文 刘畅 楚妍妍 付兴虎[1] 金娃 毕卫红[1] 付广伟[1] Zhang Jiatong;Su Liwen;Liu Chang;Chu Yanyan;Fu Xinghu;Jin Wa;Bi Weihong;Fu Guangwei(Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province,School of Information Science and Engineering,Yanshan University,Qinhuangdao 066004,Hebei,China)

机构地区：[1]燕山大学信息科学与工程学院河北省特种光纤与光纤传感重点实验室,河北秦皇岛066004

出　　处：《光学学报》2023年第23期173-181,共9页Acta Optica Sinica

基　　金：国家自然科学基金(61575170);河北省自然科学基金(F2021203045,F2021203058);河北省科技支撑计划(216Z1702G,216Z1706G)。

摘　　要：针对光频域反射(OFDR)系统中光源调频非线性导致的传感单元定位误差、传感精度低、传感范围窄、系统适应性差等问题,提出了开环校正结合光电锁相环闭环校正电流内调制分布反馈式半导体(DFB)激光器的方法。该方法用于控制DFB激光器连续、快速、大范围频率扫描线性化,使其成为OFDR系统的优质光源,提高OFDR的分辨率。实验结果表明DFB激光器的扫频非线性度由16.55%下降至0.078%,拍频信号中心频率的功率提升了21.1 dB,探测范围由15 m提升至50 m,测量值与实际值的最大误差为3.79 mm,重复性测量的最大标准偏差为112.2μm。Objective Optical frequency domain reflectometry(OFDR)systems feature high precision,high resolution,large range,strong real-time performance,and high signal-to-noise ratio.Therefore,OFDR technology has broad application prospects in aviation,transportation,and communication.After decades of this technological development,the bottleneck for its further development is that it is difficult to realize the sweep light source and optimize the signal processing,and the performance,precision,and resolution of the system are directly affected by the frequency-modulated linearity of the light source.At present,the light source employed in the system is a mechanically tuned diode laser with a wide frequency-modulated range and a narrow linewidth,but it is difficult to reduce the cost and extend the service life.The direct current modulation of distributed feedback semiconductor(DFB)lasers is a potential high-quality light source for OFDR systems because of its low cost and simple frequency modulation,but the phase noise and poor linearity of frequency modulation must be solved.Thus,we discuss the frequency modulation nonlinearity of light source in the OFDR system,such as the location difference of the sensor unit,low sensor precision,narrow sensor range of the sensor,and poor system adaptability,and propose an open-loop correction method combined with an optoelectronic phase-locked loop closed-loop correction for DFB laser.Methods The method of open-loop correction combined with photoelectric phase-locked loop closed-loop correction for DFB lasers is adopted to control the continuous,fast,and large-range frequency scanning linearization of DFB lasers.As a result,it becomes a high-quality light source for the OFDR system and improves the OFDR resolution.First,based on the direct current modulation characteristics of DFB lasers and the idea of iterative open-loop correction,the DFB laser is initially corrected,and the correction effect is evaluated by the time-frequency curve of the beat signal and the FFT power spectrum cu

关 键 词：激光器 分布反馈式半导体激光器 光频域反射 频率扫描线性化 光电锁相环 

分 类 号：TN212[电子电信—物理电子学]