ECCS-EPSRC: Micromechanical Elements for Photonic Reconfigurable Zero-Static-Power Modules

This project focuses on improving silicon photonic integrated circuits (PICs), which have important applications in telecommunications, quantum information, and artificial intelligence. Current methods to adjust or tune these circuits are inefficient, especially in cryogenic environments required for many future applications. Our approach introduces a new type of energy-efficient tuning element that doesn’t require continuous adjustment, inspired by techniques used in electronic memory chips.

This innovation will enable more compact and efficient circuits, overcoming significant barriers in the field. The project will also foster educational growth and diversity by involving graduate students and making the designs freely available to the scientific community.

In silicon photonic circuits that employ microresonators, unavoidable fabrication variations mean the resonant wavelength often needs adjustment, typically through dissipative thermal tuning. In cryogenic settings, this becomes impractical. The goal of this project is to develop a new class of switchable, digital, nonvolatile micromechanical tuning elements for photonic circuits that eliminate the need for persistent, resonator-specific tuning.

This approach harnesses the bistability in micromechanical beams, achieved through geometric engineering or intrinsic film stress with controlled release, enabling predictable beam deflections for controlled phase shifts in microresonators. This digital tuning approach allows for precise and stepwise adjustment of resonant wavelengths in large-scale photonic integrated circuits, without the need for continuous active tuning.

This approach could enable high component density, operational energy efficiency, and compatibility with standard foundry processes.

This collaborative U.S.-Swiss project is supported by the U.S. National Science Foundation (NSF) and the Engineering and Physical Sciences Research Council (EPSRC) of United Kingdom Research and Innovation (UKRI), where NSF funds the U.S. investigator and EPSRC funds the partners in the United Kingdom.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.