Thermo-switchable multi-wavelength laser emission from a dye-doped nematic liquid-crystal device

A sandwich-type laser device with a surface-relief grating inside was infiltrated with dye-doped nematic liquid-crystals which functioned as gain media. The surface-relief grating was fabricated by soft lithographic technique on a sol–gel derived zirconium-doped hybrid film using a polydimethyl–siloxane replica. The optical properties of the distributed feedback (DFB) resonator were modified by introducing a high refractive index layer consisting of niobium pentoxide subsequently. Thermal induced shift of amplified spontaneous emission spectrum, switching of multi-wavelength DFB laser emission and occurrence of random lasing were demonstrated.