Nanowire photonic crystal surface-emitting lasers (PCSELs)

光子晶体表面发射激光器（PCSELs）的最新发展已经显示出比通常使用的垂直腔表面发射激光器（VCSEL）和边缘发射激光器优越的上级性能。具有极窄光束发散度的高亮度对称光束使其在光探测和测距（激光雷达）以及光学传感应用中极具前景。通常，将形成光子晶体晶格的自顶向下蚀刻和外延过生长工艺组合以制造PCSEL。在这个项目中，我们将利用在卡迪夫大学的金属有机化学气相沉积（MOCVD）的PCSEL应用开发的InGaAs纳米线平台。这些纳米线生长在光刻定义，图案化的SOI衬底上，使用无催化剂的选择性异质外延。硅和III-V纳米线之间的纳米级界面促进了横向方向的弹性弛豫，克服了材料集成中最艰巨的挑战之一。将纳米线排列成光子晶体结构并设计纳米线阵列参数（例如晶格常数，纳米线直径，高度）以匹配光学模式的能力为新兴技术（例如带边激光器和拓扑激光器）创造了令人兴奋的机会。受资助的学生预计将专注于纳米线光子晶体结构的设计，外延和表征，并得到博士后研究人员和建模和制造合作者的支持。

Recent developments in photonic crystal surface-emitting lasers (PCSELs) have shown superior performance to commonly used vertical cavity surface emitting lasers (VCSELs) and edge emitting lasers. The high-brightness, symmetric beam with extremely narrow beam divergence make them highly promising for light detection and ranging (Lidar) and optical sensing applications. Typically, top-down etching to form photonic crystal lattices and epitaxial overgrowth processes are combined to fabricate PCSELs. In this project, we will make use of the InGaAs nanowire platform developed by the metal organic chemical vapour deposition (MOCVD) at Cardiff University for PCSEL applications. These nanowires are grown on lithographically defined, patterned SOI substrates using catalyst-free selective hetero-epitaxy. The nanoscale interface between silicon and III-V nanowires facilitates elastic relaxation in lateral directions, overcoming one of the most formidable challenges in materials integration. The ability to arrange nanowires into photonic crystal structures and to engineer the nanowire array parameters (e.g. lattice constant, nanowire diameter, height) to match optical modes creates exciting opportunities for emerging technologies such as band-edge lasers and topological lasers. The funded student is expected to be focusing on design, epitaxy and characterisations of nanowire photonic crystal structures, with support from postdoc researchers and collaborators on modelling and fabrication.