Cheng Pi-Ju, Weng Chen-Ya, Chang Shu-Wei, Lin Tzy-Rong, Tien Chung-Hao
Department of Photonics, National Chiao Tung University, Hsinchu 30010, Taiwan.
Opt Express. 2013 Jun 3;21(11):13479-91. doi: 10.1364/OE.21.013479.
We theoretically analyze plasmonic gap-mode nanocavities covered by a thick cladding layer at telecommunication wavelengths. In the presence of high-index cladding materials such as semiconductors, the first-order hybrid gap mode becomes more promising for lasing than the fundamental one. Still, the significant mirror loss remains the main challenge to lasing. Using silver coatings within a decent thickness range at two end facets, we show that the reflectivity is substantially enhanced above 95 %. At a coating thickness of 50 nm and cavity length of 1.51 μm, the quality factor is about 150, and the threshold gain is lower than 1500 cm(-1).
我们从理论上分析了在电信波长下被厚包层覆盖的等离子体间隙模式纳米腔。在存在诸如半导体等高折射率包层材料的情况下，一阶混合间隙模式比基模在激光发射方面更具潜力。然而，显著的镜面损耗仍然是激光发射的主要挑战。通过在两个端面使用厚度在合适范围内的银涂层，我们表明反射率大幅提高到95%以上。在涂层厚度为50纳米且腔长为1.51微米时，品质因数约为150，阈值增益低于1500厘米⁻¹。
