Optical Fiber Gas Sensor Based on CLC Laser Emission

This paper investigates the spectral response characteristics of cholesteric liquid crystal (CLC) lasers in acetone gas detection and explores the effects of liquid crystal film thickness on gas sensing performance. In gas sensing, the laser wavelength exhibits a blue shift as the acetone gas concentration increases, indicating the broad application potential of liquid crystal materials in environments with varying temperatures and gases. Experimental analysis of the spectral response of different liquid crystal film thicknesses <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$30 \mu \mathrm{m},\ 50 \mu \mathrm{m},\ 85 \mu \mathrm{m}$</tex> in acetone gas shows that thinner liquid crystal films are the most sensitive to acetone, displaying a larger wavelength shift. However, as the film thickness increases, the wavelength shift decreases, though the response maintains good linearity. These findings provide new insights for designing high-sensitivity gas sensors, with CLC materials demonstrating significant potential for applications in environmental monitoring, industrial safety detection, and air quality control.