GaN Photonic Crystal Laser Numerical Simulation

As the development of modern society, people’s demand of high intensity storage is growing higher. It is the era of blue disc. What matters the most in the blu-ray storage industry is the fabrication of semiconductor laser at blue wavelength. It is the goal of all researches over the world to achieve high quality, tiny scale blu-ray semiconductor laser. Photonic crystal has been taken vast range of application since its birth at the beginning of1980s. Defect photonic crystal cavity takes lots of outstanding advantages to fabricate the semiconductor laser. Comparing with the traditional semiconductor laser, photonic crystal laser has advantages of low threshold energy, tiny scale, high efficiency, controllable mode distribution.Firstly, we establish a three dimension photonic crystal structure for simulation by computer. At the same time, we get the photonic crystal cavity by removing the cell in the center of the photonic crystal structure.Secondly, we calculate the Q factor of photonic crystal cavity with different lattice constants.Thirdly, the lattice constant is changed to get the equal resonance frequency to GaN spontaneous emitting. We get the highest Q factor of2329of hexagonal photonic crystal structure.Moreover, in order to optimize the photonic crystal cavity, we add a circle of smaller air holes inside. After adding the smaller air hole, the Q factor is improved from2329to3067, almost enhanced31.7%.Finally, we sweep inner air hole radius to search the optimized parameter. It turns out that the Q factor reaches the maximum of4560, when (r/a) equals0.183. Comparing the results, the final result improves the Q factor of95.8%than the structure without inner air holes and48.7%than the unoptimized air holes.