11:00 〜 11:15
[H-6-02] Fabrication and optical characterization of a GaN-based micro-disk laser undercut by laser-assisted photo-electrochemical etching
We fabricated and optically characterized a GaN-based micro-disk laser that was undercut by photo-electrochemical (PEC) etching using a laser source. A pulsed UV laser source was utilized for PEC etching of a InGaN/GaN superlattice layer beneath the micro-disk to form the air cladding. We observed nonlinear increase in the output power of whispering gallery modes with a single InGaN quantum well gain in blue wavelengths as the pulsed photo-excitation power increased at room temperature, indicating lasing. The lasing threshold was estimated to be 236 kW/cm2. The low lasing threshold highlights the applicability of the laser-assisted PEC etching to fabrication of micro-scale visible-wavelength lasers.