Bias-free operational monolithic symmetric-connected photodiode array

Abstract

We have designed and fabricated zero-bias operational two-element symmetric-connected photodetector arrays (SC-PDAs). The designed SC-PDAs have higher saturation currents, larger RF power, and better frequency responses than the single photodetector (PD) under zero bias. The bias-free SC-PDA with 15 μm diameter of each PD demonstrated a 3 dB bandwidth of 19.4 GHz at 0.5 mA. The RF saturation photocurrent and maximum RF output power of the SC-PDA with 40 μm, 50 μm, and 60 μm diameters under zero bias are over 9.31 mA and −5.86 dBm at 3 GHz, 14.52 mA and 1.17 dBm at 1 GHz, and 13.72 mA and −1.76 dBm at 1 GHz, respectively.