Sapphire substrate-bonded ultra-low threshold 850 nm VCSEL array

Oxide-confined vertical-cavity surface-emitting laser (VCSEL) 8/spl times/8 arrays were fabricated and off set flip-chip bonded onto sapphire substrates. These devices were further wire bonded in pin-grid-array (PGA) packages as optical transmitters. Optical output of the top-emitting 850 nm VCSEL array was transmitted through the transparent sapphire substrate. Lasing threshold as low as 24 /spl mu/A was found from some of these devices at room temperature.