High-sensitivity miniature fiber-optic temperature probe based on cholesteric liquid crystal laser emission

This paper presents a method for cholesteric liquid crystal (CLC)-filled miniature optical fiber liquid crystal probes to achieve highly sensitive temperature detection. Due to the periodic structure of CLC, it can function as a resonant microcavity and generate laser light under the gain of the dye, with the laser wavelength shifting with temperature. The temperature response characteristics of several CLCs were studied by observing the variation of CLC laser wavelength with temperature. In order to further improve temperature sensitivity, this paper used a method of linear superimposing the sensitivity of two liquid crystals. Finally, the sensitivity of the fiber-optic temperature sensing probe produced in this paper reached 7.41 nm/°C. This high sensitivity was achieved by linearly combining the temperature sensitivities of CLC2 (2.77 nm/°C) and CLC4 (-4.64 nm/°C).