【摘要】 分布反馈半导体激光器的线宽一般较大,难以满足光纤传感等领域的要求。根据C.H.Henry于1982年提出的半导体激光器的线宽理论,通过适当设计DFB半导体激光器的腔长、耦合系数、微分增益、光限制因子,能有效地减小激光器的线宽。同时,空间烧孔现象也可限制DFB半导体激光器的线宽,为此需要合理设计光栅结构。在此基础上,DFB激光器的线宽能达到几十千赫兹的量级。此外,采用DBR结构或者外腔结构,也可以获得相当窄的线宽。更多还原

【Abstract】 The linewidth of distributed feedback (DFB) semiconductor lasers is usually too wide to meet the requirement of fiber-optic sensing. According to the linewidth theory of semiconductor lasers proposed by C. H. Henry in 1982, reduced linewidth can be obtained with proper design of key parameters of a DFB laser, such as cavity length, coupling coefficient, differential gain and optical confinement factor. Meanwhile, spatial-hole-burning is also detrimental to linewidth-narrowing, and special care must be paid to grating structure design to achieve narrow linewidth. By taking the above issues into consideration, DFB semiconductor lasers with a linewidth of 10-kHz have been demonstrated. In addition, ultra-narrow linewidth can be also realized by adopting DBR structure or external cavity structure.更多还原