Edge-emitting semiconductor microlasers with ultrashort-cavity anddry-etched high-reflectivity photonic microstructure mirrors

We demonstrate very compact low-threshold edge-emitting semiconductor lasers operating at a wavelength of 980 nm, in which periodic microstructure mirrors have been formed at both cavity ends by deep reactive ion etching. From a threshold analysis, we determined reflectivities of ~95% for the seven-period back reflector and ~80% for the three-period front mirror. Lasing has been achieved from 20-μm-long and 8-μm-wide devices exhibiting a current threshold of 7 mA. These are among the shortest in-plane electrically pumped lasers demonstrated so far. State-of-the-art electron beam lithography (EEL) and high-aspect ratio reactive ion etching (RIE) have been used for device fabrication