Directional emission InP/GaInAsP square-resonator microlasers

Abstract

InP/GaInAsP square-resonator microlasers with an output waveguide connected to the midpoint of one side of the square are fabricated by standard photolithography and inductively-coupled-plasma etching technique. For a 20-mum-side square microlaser with a 2-mum-wide output waveguide, cw threshold current is 11 mA at room temperature, and the highest mode Q factor is 1.0x10(4) measured from the mode linewidth at the injection current of 10 mA. Multimode oscillation is observed with the lasing mode wavelength 1546 nm and the side-mode suppression ratio of 20 dB at the injection current of 15 mA.