Resonant-cavity InGaAs-InAlAs avalanche photodiodes with gain-bandwidth product of 290 GHz

We demonstrated a high-speed, resonant-cavity InGaAs-InAlAs separate absorption, charge, and multiplication avalanche photodiode (APD) operating at a wavelength of 1.55 μm. Due to the resonant-cavity scheme, these APDs exhibit high external quantum efficiency (/spl sim/70%) and a high unity-gain bandwidth of 24 GHz. Utilizing the excellent noise characteristics of a thin InAlAs multiplication region (k/spl sim/0.18), we have also achieved a gain-bandwidth product of 290 GHz. These bandwidth results are believed to be the highest reported values for APDs operating at 1.55 μm.