Lasing Dynamics of Optically-Pumped Ultralow-Threshold Raman Silicon Nanocavity Lasers
Lasing Dynamics of Optically-Pumped Ultralow-Threshold Raman Silicon Nanocavity Lasers
复制标题
光泵浦超低阈值拉曼硅纳米腔激光器的激光动力学
DOI：
10.1103/physrevapplied.10.024039
复制
发表时间：
2018
影响因子：
4.6
通讯作者：
Noda Susumu
中科院分区：
文献类型：
--
作者：
Yamashita Daiki;Takahashi Yasushi;Kurihara Jun;Asano Takashi;Noda Susumu
我们研究了采用高品质（高Q值）纳米腔设计的光泵浦亚微瓦阈值拉曼硅激光器的激射动力学。测量结果表明，即使在0.12μW的非常低的阈值功率下，由双光子吸收产生的自由载流子在初始激光过程中也会引起动力学效应。在较高的激发功率下，拉曼激光信号在初始上升后的几百纳秒内表现出显著的降低，随后是明显的振荡。我们发现，激光信号的时间行为强烈依赖于激发波长。然而，拉曼激光信号收敛到一个稳定的连续操作在几微秒后的初始上升，在这项工作中采用的任何激发功率。数值模拟结果表明，这种振荡反映了由双光子吸收产生的自由载流子引起的热光效应和载流子等离子体效应引起的谐振波长的动态漂移。这些结果有助于理解未来采用拉曼硅纳米腔激光器的器件的正确设计。
We investigate the lasing dynamics of optically-pumped submicrowatt-threshold Raman silicon lasers that employ a high-quality (high-Q)nanocavity design. The measurements reveal that free carriers generated by two-photon absorption induce dynamic effects during the initial lasing process, even at the very low threshold power of 0.12µW. At higher excitation powers, the Raman laser signal exhibits a significant reduction within a few hundred nanoseconds after the initial rise, followed by clear oscillations. We find that the temporal behavior of the laser signal strongly depends on the excitation wavelength. However, the Raman laser signal converges to a stable continuous operation within a few microseconds after the initial rise for any excitation power employed in this work. Numerical simulations indicate that the oscillations reflect the dynamic shift of the resonant wavelength due to the thermo-optic effect and the carrier-plasma effect, which are induced by free carriers generated via two-photon absorption. These results are useful for understanding the correct design of future devices that employ Raman silicon nanocavity lasers.