In a new paper published in Light: Advanced Manufacturing, a team of scientists, led by Professor Yufei Ma from National Key Laboratory of Science and Technology on Tunable Laser, Department of Aerospace, Harbin Institute of Technology, China, and co-workers have developed a F–P-based phase demodulation of heterodyne LITES (H-LITES). The F–P cavity is comprised of an end-face of a single-mode fibre and a side of a prong of the QTF. When the QTF vibrates due to the effect of light-induced thermoelastic, the F–P cavity length varies; thus the phase changes. Because the vibration of the QTF is proportional to the gas concentration, the concentration can be inverted linearly by demodulating phase.
Compared to the H-LITES signal obtained directly from the electrical signal, the signal based on FPI had a greater SNR. The phase demodulation method can produce better detection performance, linear response, and long-term stability than the intensity demodulation method. Using the phase demodulation method, the signal peak-to-peak values are independent from power and wavelength. The phase demodulation method is immune to interference from the laser source and wavelength, and can resolve the issue of Q-point drifting due to ambient interference.
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References
DOI
Original Source URL
https://doi.org/10.37188/lam.2023.023
Funding information
This work was supported by the National Natural Science Foundation of China under Grant Nos. 62275065, 62022032, 61875047and 61505041; the Key Laboratory of Opto-Electronic Information Acquisition and Manipulation (Anhui University), the Ministry of Education (Grant No. OEIAM202202), and the Fundamental Research Funds for Central Universities.
About Light: Advanced Manufacturing
The Light: Advanced Manufacturing is a new, highly selective, open-access, and free of charge international sister journal of the Nature Journal Light: Science & Applications. It will primarily publish innovative research in all modern areas of preferred light-based manufacturing, including fundamental and applied research as well as industrial innovations.