Lin Yen-Chih, Mao Ming-Hua, Wu Chen-Jun, Lin Hao-Hsiung
Opt Lett. 2015 May 1;40(9):1904-7. doi: 10.1364/OL.40.001904.
The mid-infrared whispering-gallery-mode disk cavities with InAs0.85Sb0.15/InAs0.53P0.23Sb0.24 multiple quantum wells active medium on a GaSb substrate were fabricated. For this material system in the mid-infrared range, fabrication techniques were developed to form the disk cavity structure. The smooth sidewalls of the disk cavities were achieved by appropriate gas mixture flow ratio of BCl3/Ar in the inductively coupled plasma-reactive ion etching. In addition, selective wet etching technique was used to form the pedestal of the disk cavity using dilute hydrofluoric acid with good selectivity. For efficient confinement of the whispering gallery modes along the radial direction, the extent of the lateral etching was carefully controlled. The processed 30-μm-diameter disk cavities were optically pumped, and the whispering gallery modes with wavelengths around 4.1 μm can be observed up to 90 K.
制备了基于GaSb衬底、具有InAs0.85Sb0.15/InAs0.53P0.23Sb0.24多量子阱有源介质的中红外回音壁模式圆盘腔。对于该中红外波段的材料体系，开发了形成圆盘腔结构的制备技术。通过在电感耦合等离子体反应离子刻蚀中适当的BCl3/Ar气体混合流量比，实现了圆盘腔光滑的侧壁。此外，采用选择性湿法刻蚀技术，使用具有良好选择性的稀氢氟酸形成圆盘腔的基座。为了有效地沿径向限制回音壁模式，仔细控制了横向刻蚀的程度。对加工后的直径为30μm的圆盘腔进行光泵浦，在高达90K的温度下可观察到波长约为4.1μm的回音壁模式。
