Microwave filtering using forward Brillouin scattering in photonic-phononic emit-receive devices

TL;DR

This paper explores using forward Brillouin scattering in photonic-phononic devices to achieve narrow-band microwave filtering, leveraging long-lived acoustic resonances for improved signal processing in communication systems.

Contribution

It introduces a novel microwave filtering approach utilizing photon-phonon emitter-receiver devices based on Brillouin interactions, with theoretical analysis of noise and system optimization.

Findings

Demonstrated narrow-band filtering capabilities using Brillouin interactions.

Analyzed noise characteristics of the microwave-photonic link.

Explored parameter space for device design and optimization.

Abstract

Microwave photonic systems are compelling for their ability to process signals at high frequencies and over extremely wide bandwidths as a basis for next generation communication and radar technologies. However, many applications also require narrow-band $(\sim\text{MHz})$ filtering operations that are challenging to implement using optical filtering techniques, as this requires reliable integration of ultra-high quality factor $(\sim 10^8)$ optical resonators. One way to address this challenge is to utilize long-lived acoustic resonances, taking advantage of their narrow-band frequency response to filter microwave signals. In this paper, we examine new strategies to harness a narrow-band acoustic response within a microwave-photonic signal processing platform through use of light-sound coupling. Our signal processing scheme is based on a recently demonstrated photon-phonon emitter-receiver device, which transfers information between the optical and acoustic domains using Brillouin interactions, and produces narrow-band filtering of a microwave signal. To understand the best way to use this device technology, we study the properties of a microwave-photonic link using this filtering scheme. We theoretically analyze the noise characteristics of this microwave-photonic link, and explore the parameter space for the design and optimization of such systems.