Flip-chip bonded arrays of monolithically integrated, microlensed vertical-cavity lasers and resonant photodetectors

We present flip-chip bonded arrays of monolithically integrated vertical-cavity lasers (VCLs) and resonant photodetectors. The VCLs and photodetectors are integrated using a novel structure that allows through-the-substrate emission and detection without compromising device performance. Substrate-side microlenses have been integrated to take advantage of the through-the-substrate architecture. Flip-chip bonded VCLs exhibit threshold currents as low as 135 μA with differential efficiencies of /spl sim/53%. The detectors have the same operating wavelength as the VCLs and responsivities of 0.48 A/W, corresponding to 60% absorption, with optical bandwidths of 7 nm.