Temporally stable and continuously tunable laser device fabricated using polymerized cholesteric liquid crystals

We realized the fabrication of a temporally stabilized continuously tunable laser device using a UV-curable polymerized dye-doped cholesteric liquid crystal wedge cell. The spatial tuning resolution was less than 1 nm over a 70 nm spectral range. The continuous tuning behavior of the polymerized wedge cholesteric liquid crystal (CLC) cell is due to the fact that the concentration of the pitch gradient matches the helical pitch determined by the cell thickness. After about 1 year had elapsed, the spectral range of continuous laser tuning was nearly maintained in the polymerized CLC wedge cells. This scheme raises the possibility of practical applications of the CLC laser device, which allows for a wide tunability of single-mode laser emissions.