A high-precision temperature monitoring system based on GaAs dual-mechanism collaborative demodulation

Abstract This paper proposes a high-precision GaAs-based optical fiber temperature monitoring system that synergistically integrates two demodulation mechanisms. The system employs interference spectroscopy for precise temperature measurement and simultaneously uses absorption edge reflection spectroscopy to localize the temperature range, effectively overcoming the ambiguity caused by overlapping interference spectra in wide-range measurements. Within the temperature range of -20 °C to 150 °C, the system achieves a wavelength demodulation resolution of 0.1 pm, an average temperature error of ±0.1607 °C, and an absorption edge sensitivity of 0.36 nm/°C. Experimental results demonstrate its capability for high-precision, wide-range measurements, enabling applications in aerospace engine monitoring and medical diagnostics. This work provides a robust solution for temperature sensing in complex environments.