Electro-tunable liquid crystal laser based on high-Q Fabry-Pérot microcavity

We demonstrate an electro-tunable laser based on a plano-concave (p-c) Fabry-Pérot (FP) microcavity filled with dye-doped liquid crystal (LC) gain material. Owing to the high Q-factor of the p-c FP microcavity, the lasing threshold of the LC laser is as low as 0.58 µJ/mm². The single-mode emission wavelength can be easily tuned by varying applied voltage, which induces the reconfiguration of LC molecules. Furthermore, this lasing platform operates at room temperature, thanks to the wide temperature range of the nematic LC. We believe that our LC laser is widely applicable to light sources of various micro total analysis systems.