Li Guangyuan, Liu Xinfeng, Wang Xingzhi, Yuan Yanwen, Sum Tze Chien, Xiong Qihua
Opt Express. 2015 Jun 15;23(12):15657-69. doi: 10.1364/OE.23.015657.
As miniaturized light sources of size beyond the optical diffraction limit, surface plasmon lasers are of particular interest for numerous exciting applications. Although convincing demonstrations of plasmonic lasing have been reported with the metal-insulator-semiconductor (MIS) hybrid design using semiconductor nanomaterials, it remains a challenge that conventional photonic lasing may be triggered and misinterpreted as plasmonic lasing. One way to address this issue is to cut off photonic modes in the waveguide by strictly restricting the semiconductor thickness. Here we propose a novel hybrid design, namely the dielectric-metal-insulator-semiconductor (DMIS) design that potentially solves the challenge. Taking advantage of strong polarization selectivity by reflection effect in favor of the plasmonic mode, whispering-gallery mode cavities based on the proposed DMIS design suppress possible photonic lasing modes and relieve the semiconductor thickness for purified plasmonic lasing. Using these cavities, we demonstrate room-temperature purified plasmon lasing with cadmium sulphide square nanobelts atop of a deposited multilayer film. Approaches for further improvement of the plamsonic lasing performance are discussed. Our design provides a reliable platform for developing better surface plasmon nanolasers using new semiconductor nanomaterials.
作为尺寸超出光学衍射极限的小型化光源，表面等离子体激元激光器在众多令人兴奋的应用中具有特别的吸引力。尽管已经报道了使用半导体纳米材料的金属 - 绝缘体 - 半导体（MIS）混合设计实现了令人信服的等离子体激元激光演示，但传统光子激光可能被触发并被误判为等离子体激元激光仍然是一个挑战。解决这个问题的一种方法是通过严格限制半导体厚度来截止波导中的光子模式。在此，我们提出一种新颖的混合设计，即介电 - 金属 - 绝缘体 - 半导体（DMIS）设计，它有可能解决这一挑战。基于所提出的DMIS设计的回音壁模式腔利用反射效应产生的强偏振选择性来支持等离子体激元模式，抑制可能的光子激光模式，并放宽半导体厚度以实现纯净的等离子体激元激光。利用这些腔，我们在沉积的多层膜顶部用硫化镉方形纳米带演示了室温下的纯净等离子体激元激光。还讨论了进一步提高等离子体激元激光性能的方法。我们的设计为使用新型半导体纳米材料开发更好的表面等离子体激元纳米激光器提供了一个可靠的平台。
