Si microring resonator optical switch based on optical phase shifter with ultrathin-InP/Si hybrid metal-oxide-semiconductor capacitor

Abstract

We propose a microring resonator (MRR) optical switch based on III-V/Si hybrid metal-oxide-semiconductor (MOS) optical phase shifter with an ultrathin InP membrane. By reducing the thickness of the InP membrane, we can reduce the insertion loss of the phase shifter, resulting in a high-quality-factor (Q-factor) MRR switch. By optimizing the device structure using numerical analysis, we successfully demonstrated a proof-of-concept MRR optical switch. The optical switch exhibits 0.3 pW power consumption for switching, applicable to power-efficient, thermal-crosstalk-free, Si programmable photonic integrated circuits (PICs) based on wavelength division multiplexing (WDM).

Si Microring Resonator Crossbar Array for On-Chip Inference and Training of the Optical Neural Network

“…Supposing that the PIC is controlled with conventional electrical hardware, the clock frequency for MVM was assumed to be 3 GHz. At this clock frequency, high-speed III–V/Si hybrid metal-oxide-semiconductor (MOS) optical phase shifters can be used to replace the slow TO phase shifters used in this proof-of-concept demonstration. − Hybrid MOS phase shifters also eliminate the thermal crosstalk of TO phase shifters, thereby significantly simplifying the control of the MRRs. Previously, we have fabricated MRR switches based on the III–V/Si hybrid MOS phase shifter using a 30 nm thick III–V membrane .…”

“…Previously, we have fabricated MRR switches based on the III−V/Si hybrid MOS phase shifter using a 30 nm thick III−V membrane. 54 For a 100 × 100 MRR crossbar array, the computation speed is expected to be approximately 60 TOPS. We further evaluate the power consumption for static inference tasks, where the weights can be considered constant.…”

An Electro-Photonic System for Accelerating Deep Neural Networks

“…In the opposite case, no voltage is applied to the MRR so the optical signal is coupled and routed through the bypass waveguide with no phase shifter (see Fig. MRR switches can be reprogrammed at tens of Gb/s with a much smaller optical loss compared to high-bandwidth phase shifters for single-bit operation [34]. This enables us to use low-bandwidth low-loss phase shifters [3] and leverage data reuse while achieving high speed.…”

“…Once the values in the phase shifters are settled, one RNS-MMVM operation is completed every 0.1 ns (10 Giga MVMs per second). This operation rate is based on the modulation bandwidth of the MRRs [34]. ADCs [56] achieve ≥10 GS/s sampling rate so they do not cause a latency overhead when the operations are pipelined.…”

“…The 25 µm actuation length of the phase shifter causes 0.04 dB loss and can achieve 5.65π radian phase shift [3]. Each MRR has a radius of 10 µm and a total (insertion and propagation) loss of 0.2 dB when coupled [34]. MRRs use electro-optical tuning that does not suffer from thermal crosstalk and has a very small power consumption of 0.3 pW for switching [34].…”