Room-temperature capsule-shaped wavelength-scale metal-clad laser operating at 1550 nm

We fabricate a capsule-shaped metal-clad wavelength-scale cavities on InP and demonstrate room-temperature lasing at 1550-nm wavelength. By introducing an optimized curvature to the sidewalls of a conventional rectangular metal-clad laser, we effectively reduce the optical loss of transverse-electric (TE) mode and experimentally confirm, for the first time, clear improvement in side mode suppression ratio and slope efficiency of the laser under pulsed optical pumping.