可连续调谐的窄线宽外腔半导体激光器  

Continuously Tunable Narrow Linewidth External⁃Cavity Semiconductor Lasers

作　　者：邓力华 阎柏屹 梁伟 Deng Lihua;Yan Baiyi;Liang Wei(School of Nano-Tech and Nano-Bionics,University of Science and Technology of China,Hefei 230026,Anhui,China;Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,Jiangsu,China;Xi’an Jiaotong-Liverpool University,Suzhou 215123,Jiangsu,China)

机构地区：[1]中国科学技术大学纳米技术与纳米仿生学院,安徽合肥230026 [2]中国科学院苏州纳米技术与纳米仿生研究所,江苏苏州215123 [3]西交利物浦大学,江苏苏州215123

出　　处：《中国激光》2023年第23期253-256,共4页Chinese Journal of Lasers

基　　金：国家自然科学基金(62075233);中国科学院稳定支持基础研究领域青年团队计划(YSBR-69)。

摘　　要：可快速连续调谐的小尺寸窄线宽外腔半导体激光器是调频连续波(FMCW)激光雷达、量子技术等领域的核心器件。通过紧凑的反馈光路设计,采用腔长为2.5 mm的法布里-珀罗腔(FP腔)反馈压窄线宽,并结合压电陶瓷(PZT)进行腔长扫描,组装了波长为1550 nm的小型化可调频的激光样机。采用光纤长度为1 m的马赫-曾德尔干涉仪,在重复频率为0.1、1.0、10.0、100.0 kHz下分别测得激光器无跳模的连续调谐范围为25.0、21.6、18.0、10.0 GHz。基于20 km长光纤的延时自外差法,测得3 dB线宽约为10 kHz。未来通过更加紧凑的光路设计,可以获得更大调频范围的超窄线宽激光。Objective The advancement of continuously tunable,miniaturized,narrow-linewidth external-cavity semiconductor lasers holds a key position in applications such as continuous-wave LIDAR and quantum technologies.By coupling a distributed feedback(DFB)laser with a short Fabry-Perot(FP)cavity and using piezoelectric ceramics(PZT)for cavity length modulation,a miniaturized tunable laser system operating at a wavelength of 1550 nm is realized.Experimental validation using a Mach-Zehnder interferometer(differential fiber length of 1 m)reveals a mode-hop-free tuning range exceeding 10 GHz.The frequency tuning ranges of 25.0,21.6,18.0,and 10.0 GHz are demonstrated at the repetition rates of 0.1,1.0,10.0,and 100.0 kHz,respectively.Additionally,utilizing the self-delayed heterodyne technique,the laser exhibits a 3 dB linewidth approaching 10 kHz.Forthcoming endeavors would aim to achieve a broader tuning range with a narrower linewidth by optimizing the optical pathway and modifying the cavity mirror reflectivity.Methods This study introduces a meticulously designed butterfly encapsulated laser module with dimensions of 20.8 mm×12.7 mm×8.9 mm.The configuration leverages a dual-output 1550 nm DFB laser diode that is controlled in terms of both current and temperature via an in-house circuit system.A schematic of the laser architecture is shown in Fig.1.The optical resonator is formed by a planar mirror(M1)and concave mirror(M2),with M2 affixed to the PZT.This fosters cavity length modulation.Emissions from the DFB diode undergo meticulous collimation via a silicon lens and propagate within the cavity.Subsequently,these leak out of the cavity and are fed back into the diode.This results in a self-injection-locked state.The feedback phase is controlled using a heating resistor placed on top of a silicon lens.Results and Discussions Linewidth evaluations are conducted using a 20 km fiber-based self-delayed heterodyne measurement system.The spectral characterizations reveal a 20 dB linewidth close to 200 kHz,as shown in Fig.3.T

关 键 词：激光器 连续调频 法布里-珀罗外腔半导体激光 自注入锁定 

分 类 号：TN248[电子电信—物理电子学]