Microfabrication of vertical-cavity surface-emitting laser cavities

We have reduced the threshold voltages and currents of vertical cavity surface emitting lasers by using dielectric high reflectivity mirrors which were deposited after the diode fabrication step. This device fabrication sequence is able to correct for inaccuracies in the crystal growth and allows the future development of more complex laser structures. The quantum-well based laser diodes were demonstrated at 0.72 µm, 0.85 µm, and 1.55 µm. Threshold currents and voltages of our 0.85 µm lasers were 2.8 mA at 1.7 V pulsed, and 4 mA when cw-pumped. The threshold currents of 5x7 µm^2 area 1.55 µm devices were 17 mA