Simple method for microwave photonic temperature interrogation with high resolution and sensitivity

Opt Lett. 2022 Sep 15;47(18):4750-4753. doi: 10.1364/OL.465656.

Abstract

We propose a microwave photonic temperature interrogation system with high resolution and sensitivity based on temperature-to-time mapping with a simple structure. In this work, a bidirectional chirped optical signal is constructed, and the temperature information is mapped to the time interval change of the output pulses by filtering the bidirectional chirped optical signal using the transmission spectrum of a Fabry-Perot filter. Only a low-speed oscilloscope is required to extract the time interval of the output pulses in the proposed scheme, and complex data processing as well as synchronizing processes are avoided. In a proof-of-concept experiment, a high temperature interrogation sensitivity of 18.24 µs/°C and a high resolution of 0.035°C are realized, demonstrating good potential for practical applications.