Analysis of mode characteristics for hexagonal resonator lasers  

作　　者：吴文广 王加贤 黄永箴 

机构地区：[1]College of Information Science and Engineering,Huaqiao University [2]State Key Laboratory on Integrated Optoelectronics,Institute of Semiconductors,Chinese Academy of Sciences

出　　处：《Optoelectronics Letters》2010年第4期256-260,共5页光电子快报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.60838003);the Natural Science Foundation of FujianProvince (No. 2009J01291)

摘　　要：Mode characteristics of hexagonal resonators are numerically simulated by the two-dimensional(2-D) finite-difference time-domain(FDTD) technique.For the hexagonal resonator with the side length of 3 μm and the refractive index of 3.2,the mode quality(Q) factors decrease from 104 to 102 as the resonant wavelength increases from 1.1 to 3.2 μm.The modes have a relatively high Q factor as their even and odd states have different mode wavelengths and different Q factors,i.e.,they are accidentally degenerate modes.The azimuthal mode numbers obtained from mode field distribution for the accidentally degenerate modes satisfy the mode number relation derived from the symmetry characteristics for the split of double-degenerate modes.Furthermore,the numerical results indicate that an output waveguide parallel to one of the sides is the better scheme for directional emission.For the hexagonal resonator with 3 μm side length and 0.3 μm wide output waveguide,the Q factor of 5.05×103 and output efficiency of 33% are obtained at the mode wavelength of 1.29 μm.Mode characteristics of hexagonal resonators are numerically simulated by the two-dimensional（2-D） finite-difference time-domain（FDTD） technique.For the hexagonal resonator with the side length of 3 μm and the refractive index of 3.2,the mode quality（Q） factors decrease from 10^4 to 10^2 as the resonant wavelength increases from 1.1 to 3.2 μm.The modes have a relatively high Q factor as their even and odd states have different mode wavelengths and different Q factors,i.e.,they are accidentally degenerate modes.The azimuthal mode numbers obtained from mode field distribution for the accidentally degenerate modes satisfy the mode number relation derived from the symmetry characteristics for the split of double-degenerate modes.Furthermore,the numerical results indicate that an output waveguide parallel to one of the sides is the better scheme for directional emission.For the hexagonal resonator with 3 μm side length and 0.3 μm wide output waveguide,the Q factor of 5.05×103 and output efficiency of 33% are obtained at the mode wavelength of 1.29 μm.

关 键 词：模式特性 谐振腔 激光器 有限差分时域 谐振波长 输出波导 FDTD法 数值模拟 

分 类 号：TN248[电子电信—物理电子学]