设计了一种具有内腔耦合层的850 nm液晶可调谐垂直腔面发射激光器(VCSEL)结构, 从而获得了更宽的波长调谐范围以及稳定的偏振模式输出。通过分析在不同液晶层厚度下, 两种偏振模式的共振波长以及对应的阈值增益的变化关系, 研究了液晶厚度影响可调谐VCSEL偏振模式和波长调谐的机理。此外, 通过优化半导体腔和液晶腔之间的耦合层结构, 使得基于液晶的可调谐VCSEL结构在实现稳定偏振模式输出的基础上具有更宽的波长调谐范围。结果表明, 耦合层结构的加入可以有效地增大液晶可调谐VCSEL的调谐范围, 最大达到41.1 nm。同时, 在连续的波长调谐过程中, 由于o光偏振模式始终处于受抑制状态, 因此液晶可调谐VCSEL可实现稳定的单偏振模式输出。

In this paper, we designed an 850 nm liquid crystal tunable vertical-cavity surface-emitting laser(VCSEL) structure with internal coupling layer to optimize the wavelength tuning range and polarization stability of the device. The resonance wavelength and the corresponding threshold gain of the two polarization modes are analyzed under different liquid crystal layer thicknesses, and the effect of liquid crystal thickness on the tunable VCSEL polarization mode and wavelength tuning is studied. In addition, we add a coupling layer structure between the semiconductor cavity and the liquid crystal cavity, which can make the liquid crystal tunable VCSEL structure realize stable polarization mode and wider wavelength tuning range. The results show that the coupling layer structure can effectively increase the tuning range of liquid crystal tunable VCSEL to 41.1 nm. At the same time, because the polarization mode of o-beam is always suppressed, the liquid crystal tunable VCSEL can achieve stable single polarization mode output in the continuous wavelength tuning process.