Work

Precise Temperature Measurement Through Wavelength Modulation Heterodyne Phase-Sensitive Dispersion Spectroscopy

Year: 2025

Type: article

Abstract: This work proposes a precise temperature measurement method based on wavelength modulation heterodyne phase-sensitive dispersion spectroscopy (WM-HPSDS). Before the light intensity of the laser was modulated by an electro-optic modulator to generate a three-tone beam, the laser produced additional wavelength modulation by superimposing a high-frequency sinusoidal waveform on a slow sawtooth wave. The second harmonic peak value of the H2O dispersion phase at 7185.59 cm−1 and 7182.94 cm−1 was used to extract temperature through two-line thermometry. The experiment was carried out on a water-based thermostat and an acoustically excited Bunsen burner. The extracted temperatures of the thermostat agreed well with the reference temperature, and the deviation was within 1.5 °C. The measurement stability of the Bunsen burner flame was approximately 10.4 dB higher than that of direct HPSDS. Furthermore, measuring the peak values under varying laser powers demonstrated that WM-HPSDS was immune to optical power fluctuations. Therefore, this method has potential for measuring temperature in harsh environments.

Source: Photonics

DOI: 10.3390/photonics12060537

Authors: Guoquan Wang, Rende Wang, Weiqian Zhao

Institutions: Beijing Institute of Technology, China Electronics Technology Group Corporation, Beihang University

Language: English

Topic: Spectroscopy and Laser Applications

Subfield: Spectroscopy

Field: Chemistry

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,896

Funder: National Key Research and Development Program of China