Distributed temperature sensing on silicon-on-insulator chip by optical frequency domain reflectometry

Abstract

This study introduces a novel distributed temperature sensing (DTS) technique on silicon-on-insulator (SOI) chips by the optical frequency domain reflectometry (OFDR) technology. In contrast to traditional on-chip silicon photonics temperature sensors which rely on transmission spectrum detection, this method is based on Rayleigh backscatter induced by the sidewall roughness of as-fabricated waveguides, eliminating the need for a specially designed structure. On-chip DTS results with a remarkable sensing spatial resolution of 200 μm and a high temperature sensitivity of 88 pm/K are demonstrated within the temperature range from 22.8 ∘C to 200 ∘C. Furthermore, the technology is employed to measure non-uniform temperature distributions along an SOI waveguide generated by integrated heaters. Importantly, this approach offers a straightforward sensing structure, opening new possibilities for investigating temperature profiles and thermal crosstalk across the chip.