Continuous wave top surface emitting quantum well lasers using hybrid metal/semiconductor reflectors

Continuous wave lasing at room temperature of vertical cavity top surface emitting quantum well lasers using hybrid metal/semiconductor reflectors is demonstrated. Semi-transparent metal films, about 350 A thick, are used with a reduced number of periods of distributed Bragg reflectors to form a hybrid top mirror with greatly reduced electrical resistance. Voltage at a threshold current of 11 mA is as low as 3.2 V and 100Ω differential series resistance is obtained with lO =m diameter devices. Improved uniformity and yield were obtained using silver/gold thin films deposited in-situ under ultra-high vacuum after molecular beam epitaxial growth of the semiconductor layers.