Electrically interfaced Brillouin-active waveguide for multi-domain transduction

TL;DR

This paper introduces a wide-bandwidth electro-optomechanical waveguide with integrated piezoelectric transducer enabling efficient bidirectional optical-microwave conversion and multi-channel microwave photonic filtering, advancing quantum and classical signal processing.

Contribution

It presents a novel electro-optomechanical waveguide system with integrated piezoelectric transducer for wide-bandwidth, bidirectional microwave-optical transduction and multi-channel filtering, surpassing previous limited-bandwidth approaches.

Findings

Achieved quantum efficiency of up to -54.16 dB in microwave-to-optical conversion.

Demonstrated a wide optical bandwidth (>100 nm) for electro-optomechanical transduction.

Implemented a multi-channel microwave photonic filter using segmented waveguides with distinct resonances.

Abstract

New strategies to convert signals between optical and microwave domains could play a pivotal role in advancing both classical and quantum technologies. Through recent studies, electro-optomechanical systems have been used to implement microwave-to-optical conversion using resonant optical systems, resulting in transduction over limited optical bandwidth. Here, we present an optomechanical waveguide system with an integrated piezoelectric transducer that produces electro-optomechanical transduction over a wide optical bandwidth through coupling to a continuum of optical modes. Efficient electromechanical and optomechanical coupling within this system enables bidirectional optical-to-microwave conversion with a quantum efficiency of up to $-$54.16 dB. When electrically driven, this system produces a low voltage acousto-optic phase modulation over a wide ($>$100 nm) wavelength range. Through optical-to-microwave conversion, we show that the amplitude-preserving nature inherent to forward Brillouin scattering is intriguing and has the potential to enable new schemes for microwave photonic signal processing. We use these properties to demonstrate a multi-channel microwave photonic filter by transmitting an optical signal through a series of electro-optomechanical waveguide segments having distinct resonance frequencies. Building on these demonstrations, such electro-optomechanical systems could bring flexible strategies for modulation, channelization, and spectrum analysis in microwave photonics.