Transparent in-line optical power monitor integrated with MOS optical phase shifter using InP/Si hybrid integration

We demonstrate a transparent in-line optical power monitor using an InP-based phototransistor monolithically integrated with an InP/Si hybrid MOS optical phase shifter. The trap-mediated photodetection and amplification by phototransistor enables photodetection down to -44 dBm with an optical insertion loss of <0.25 dB.