[21p-A205-1~21] 3.14 Silicon photonics and integrated photonics (formerly 3.15)

△ [21p-A205-13] High-responsivity, Low-capacitance Si Slot Hybrid Waveguide Photodetector using Ultrathin InGaAs Membrane

〇Tomohiro Akazawa¹, Dongrui Wu¹, Kei Sumita¹, Naoki Sekine¹, Makoto Okano², Kasidit Toprasertpong¹, Shinichi Takagi¹, Mitsuru Takenaka¹ (1.The Univ. of Tokyo, 2.AIST)

Keywords:Silicon Photonics, Photodetector

Optical interconnects have been widely implemented into shorter scales such as rack-to-rack communications in a data center due to their high-speed performance, but the power consumption of the receiver system has become an issue. Since the receiver system consists of a photodetector (PD) and TIA and consumes a large amount of power due to the electrical amplification, a "receiver-less" method which directly converts photocurrent to voltage signals with a high load resistance has been proposed. However, to achieve RC bandwidth more than 10 GHz while maintaining sufficient voltage swing, the PD capacitance must be on the order of 1 fF. Although a PD with high responsivity and low capacitance using InP photonic crystals has been reported, its integration with a Si photonics platform remains to be difficult. In this study, we report a Si hybrid PD consisting of an ultrathin InGaAs membrane bonded onto a Si slot waveguide, which enables high responsivity and low capacitance.