向列相液晶染料可调谐激光器的研究

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

对向列相液晶染料的可调谐激光器进行了光学特性研究.以650 nm为中心波长设计了SiO_2和TiO_2多层膜的一维光子晶体,以激光染料与向列相液晶的混合物作为增益介质层,制备了波长可调谐激光器.用Nd:YAG倍频脉冲激光器输出的532 nm激光抽运所制备的激光器样品得出如下光学特性:激光发射波长随温度调谐范围为605.5—639.8 nm,达到34.3 nm,随电压调谐范围为634.5—619.5 nm,达到15 nm.发射激光每脉冲的阈值能量为12.3μJ,激光线宽小于1 nm.

We investigate the optical characteristics of the tunable laser of a one-dimensional photonic crystal（ID PC） containing Dye-doped nematic liquid crystal（NLC）.The dielectric multilayer consisting of an alternating stack of SiC〉2 and TiO2 layers is used as the ID 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 12.3μJ/pulse,and the linewidth of the emission peak was less than 1 nm.