Investigation of the tunable laser of one-dimensional photonic crystal with dye-doped nematic liquid crystal defect layer

Abstract

We investigate the optical characteristics of the tunable laser of a one-dimensional photonic crystal (1D PC) containing Dye-doped nematic liquid crystal (NLC). The dielectric multilayer consisting of an alternating stack of SiO2 and TiO2 layers is used as the 1D PC whose defect layer is filled with the laser dye and NLC. The central wavelength of the stop band of the 1D PC is 650 nm. A second-harmonic light of a Q-switched Nd: YAG laser has a wavelength of 532 nm, and is used for excitation. With the temperature increasing from 25.5 ℃ to 48 ℃, the emission wavelength of the tunable laser is continuously shifted from 605.5 to 639.8 nm, the total wavelength shifts is 34.4 nm. With the external voltage increasing from 0 to 2.86 V, the emission wavelength of the tunable laser is shifted from 634.5 to 619.5 nm, the total wavelength shifts are 15 nm. The lasing threshold was about 12.3 J/pulse, and the linewidth of the emission peak was less than 1 nm.