On-chip correlation-based Brillouin sensing: design, experiment and simulation

TL;DR

This paper demonstrates on-chip Brillouin sensing using BOCDA to detect local geometrical features in silicon-chalcogenide waveguides, supported by simulations of mode interactions and spectrum analysis.

Contribution

It introduces a novel on-chip Brillouin sensing method with experimental validation and detailed simulation of mode effects on the spectrum.

Findings

Detection of 200μm features along waveguides

Analysis of mode interactions affecting Brillouin spectrum

Experimental and simulation validation of sensing technique

Abstract

Wavelength-scale SBS waveguides are enabling novel on-chip functionalities. The micro- and nano-scale SBS structures and the complexity of the SBS waveguides require a characterization technique to monitor the local geometry-dependent SBS responses along the waveguide. In this work, we experimentally demonstrate detection of longitudinal features down to 200$\mu$m on a silicon-chalcogenide waveguide using the Brillouin optical correlation domain analysis (BOCDA) technique. We provide simulation and analysis on how multiple acoustic and optical modes and geometrical variations influence the Brillouin spectrum.