Directional emission InP/GaInAsP square-resonator microlasers

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-mu m-side square microlaser with a 2-mu m-wide output waveguide, cw threshold current is 11 mA at room temperature, and the highest mode Q factor is 1.0 X 10(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. (C) 2008 Optical Society of America

National Natural Science Foundation of China (NNSFC) 60777028 60723002Major State Basic Research Program 2006CB302804 We gratefully acknowledge Jiao-Qing Pan for providing the laser wafer and financial support from National Natural Science Foundation of China (NNSFC) under grants 60777028 and 60723002, and the Major State Basic Research Program under grant 2006CB302804.