All-Silicon Photodetectors for Photonic Integrated Circuit Calibration

All-silicon highly-doped PN junction-based photodetectors, for photonic integrated circuit (PIC) calibration and power monitoring, are designed and fabricated in the C-band. The photodetector response is measured for different doping conditions. The photodetectors are integrated with an interferometric based phase-interrogator structure for a test calibration circuit. The measured devices show high responsivity (12 A/W) obtained under avalanche condition at 5.7 V reverse bias and reasonable dark current (1 μA) due to photon assisted tunneling effect and are therefore, proved to be an ideal candidate for power monitoring and phase calibration of PICs.