Plasmonic-based GaAs balanced metal-semiconductor-metal photodetector with high common mode rejection ratio

We propose and demonstrate a plasmonic-based GaAs balanced metal-semiconductor-metal photodetector (BMSM-PD) structure. A dual-beam FIB/SEM is employed for the fabrication of the metal nano-gratings and slits of the B-MSMPD. A common mode rejection ratio (CMRR) value less than 25 dB at 830nm wavelength, dependent on the applied bias, is measured. This adequate CMRR value indicates that the BMSM-PD structure substantially suppresses laser intensity noise, making it suitable for ultra-high-speed optical telecommunication systems. In addition, this work paves the way for the monolithic integration of B-MSM-PDs into large scale semiconductor circuits.