Nonreciprocity in Integrated Optical and Microwave Optomechanical Based Systems
Abstract
During this program, we reported acousto-optic modulation of a silicon nitride micro-resonator utilizing high-overtone bulk acoustic wave resonances (HBAR), where the acoustic wave penetrates vertically towards the substrate. Although HBAR is frequently used in contemporary communication, sensors, and superconducting circuits, this was the first time it was used on a photonic integrated chip. To enhance the electromechanical and optomechanical coupling efficiency, we focused our efforts on fabricating hybrid integrated released MEMS-photonic devices. This was achieved by releasing Si substrate below the actuators, leaving a thin acoustic cavity mainly consisting of the silicon oxide cladding embedding the silicon nitride waveguides, which led to the demonstration of magnet-free optical isolation via angular momentum biasing. Secondly, we have recently proposed and comprehensively analyzed a new kind of transducer harnessing the strong piezoelectric coupling of microwave signals to a mechanical excitation, a high overtone bulk acoustic resonance (HBAR), parametrically interacting with optical super-modes of optically coupled ring cavities to realize a coherent microwave-optical conversion. This device takes advantage of the high-quality factors of silicon nitride waveguides fabricated using the photonic damascene process. The integration of micro-electro-mechanical (MEMS) actuators on top of these waveguides allows for modulation using stress-optical phenomena, namely the moving boundaries and photoelastic effects. An important step in the modular approach to quantum computing can be made possible by improvements to these transducers, such as grounding for cryogenic compatibility and release process optimization, which would also make it much easier to build up quantum networks.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 12, 2023
- Accession Number
- AD1226625
Entities
People
- Tobias Kippenberg