Output Coupling and Spectral Control in 1550-nm Micro-Disc Lasers Using Defects on the Rim

We demonstrated room-temperature continuous-wave (RTCW) operation of electrically driven in-plane emitting micro-disc lasers with radius of 10 μm. The disk cavity was fabricated using high resolution electron beam lithography based on hydrogen silsesquioxane (HSQ) and BCl
₃
-Cl
₂
-Ar inductively coupled plasma etching. By using circular bump or notch defects on the circumference as output coupling as well as mode control mechanisms, single-mode operation for large bump defect lasers with sidemode suppression ratio larger than 30 dB was observed, with highly directional output emission.