Lasing in a ZnO membrane microcavity with designable shape fabricated by focused ion beam milling

We show a three-dimensional membrane cavity fabrication technique and corresponding lasing characteristics of the fabricated rectangular ZnO membrane microcavity (MC) using optical injection. The ZnO membrane was cutfrom a single crystalline ZnO substrate by using a focused ion beam, and was then placed onto a SiO₂ substrate by using a glass tip. The micro-photoluminescence measurement performed on the fabricated ZnO membrane MC at 77 K showed an obvious feature of lasing action including non-linear increasing of intensity and linewidth narrowing. By using this fabrication approach, various MCs with desired shapes can be made.