宽调谐范围垂直腔面发射激光器特性分析及设计

Investigation and design of widely tunable vertical-cavity surface emitting lasers

运用光学传输矩阵和有限元方法对波长可调谐垂直腔面发射激光器(VCSELs)的波长调谐范围进行了研究.对中心波长为980nm的可调谐VCSELs的波长调谐特性和微电子机械系统(MEMS)悬臂梁结构进行了设计,并进行了实验研究.结果表明,MEMS可调谐VCSELs调谐特性同时受到光波谐振腔结构和悬臂梁最大位移的共同影响.在悬臂梁几何尺寸和激光器有源区结构一定的条件下,通过优化可调谐VCSELs的牺牲层厚度可实现大范围波长调谐.同时,对可调谐VCSELs整体结构进行了设计,计算结果显示波长调谐范围达到30nm以上,调谐效率达到0.12,调谐过程中所有激射波长都处在InGaAs/GaAs量子阱高增益区.

The tuning characteristics of widely tunable wavelength vertical-cavity surface-emitting lasers （VCSELs） have been investigated based on transfer matrix model and finite-element structure-electric coupled-field analysis model and experiment, in which the electrostatic tuning of wavelength and microelectronic mechanical system （MEMS） cantilever of the tunable VCSELs with central wavelength 980 nm were designed. The analysis shows that the characteristics of wavelength tuning of VCSELs will be affected by the maximal displacement of cantilever and the structure of wavelength resonator. The tuning range can be improved based on the optimization of sacrificial layer for a given geometry of cantilever and active region of the device. In this paper, the structure of tunable VCSEL is designed. Further numerical simulations show that a continuous tuning range up to 32 nm is obtainable, tuning efficiency is 0.12, and the whole tuning range of wavelength lies within the high gain region of the InGaAs quantum wells with GaAs barrier.