The Monolithic Integration of GaAs–AlGaAs-Based Unitraveling-Carrier Photodiodes With Zn-Diffusion Vertical-Cavity Surface-Emitting Lasers With Extremely High Data Rate/Power Consumption Ratios

In this letter, we demonstrate the monolithic integration of high-speed GaAs-AlGaAs-based unitraveling-carrier photodiode (UTC-PD) with Zn-diffusion vertical-cavity surface-emitting lasers (VCSELs), both with very high data rate/power consumption ratios for the application to bidirectional optical interconnect. Under zero-bias operation, the integrated UTC-PD exhibits reasonable external efficiency (48%), wide 3-dB bandwidth (13 GHz), and 10-Gb/s eye-opening from low to high output photocurrents (0.1-0.4 mA) without integrating with any active ICs. Regarding the integrated Zn-diffusion VCSEL, it can achieve 10-Gb/s eye-opening under a prebias current as small as 3 mA and a very small RF driving voltage (0.25 V_p-p driving voltage). The data rate/power consumption ratio of the VCSEL is extremely high, as much as 2.4 Gb/s middotmW^-1.