Electrically-pumped vertical-cavity lasers with AlxOy-GaAs reflectors

We have fabricated the first electrically-pumped vertical-cavity surface-emitting lasers (VCSEL's) which use oxide-based distributed Bragg reflectors (DBR's) on both sides of the gain region, They require a third the epitaxial growth time of VCSEL's with semiconductor DBR's, We obtain threshold currents as low as 160 mu A in VCSEL's with an active area of 8 mu m x 8 mu m using a two quantum well InGaAs-GaAs active region, By etching away mirror pairs from the top reflector, quantum efficiencies as high as 61% are attained, while still maintaining a low threshold current of 290 mu A.