基于WGM微腔自注入锁定压窄线宽技术研究

Research on microcavity self injection locking narrow linewidth technology based on WGM

回音壁模式(whispering gallerymode,WGM)微腔具有超高Q值和极小的模式体积,并且还存在一种弱后向瑞利散射。利用WGM微腔的该反馈机制,可以实现激光线宽几个数量级的压缩,基于此设计了一种窄线宽激光器。利用数值仿真分析了自注入锁定过程中的光学行为,具体而言分析了系统中相位、失谐、后向散射、耦合效率的变化对系统性能的影响。同时并使用半导体激光器进行了验证实验,半导体激光器中心波长为1552.126nm,实验中将7 MHz线宽激光输出压窄至500kHz。基于该方案实现的窄线宽激光器具有轻量化、便捷性高、性能稳定等诸多优点。因而,这种窄线宽激光器在激光干涉测量、激光陀螺、激光测距等领域具有潜在的应用价值。

Whispering Gallery Mode(WGM)microcavities exhibit ultrahigh Q factors and extremely small mode volumes,along with weak backward Rayleigh scattering.By utilizing this feedback mechanism in WGM microcavities,a laser linewidth compression by several orders of magnitude can be achieved,based on which a narrow linewidth laser is designed.Numerical simulations were used to analyze the optical behavior during the self injection locking process,specifically the effects of changes in phase,detuning,backscattering and coupling efficiency on the system performance.Additionally,experimental validation is performed using a semiconductor laser with a central wavelength of 1552.126nm,and the 7 MHz linewidth laser output was narrowed to 500 kHz in the experiments.The narrow linewidth laser achieved through this approach has many advantages such as lightweight,high convenience,and stable performance.As a result,this narrow linewidth laser holds potential applications in areas such as laser interferometry,laser gyroscopes,laser ranging,and other related fields.