正三角形及正方形微光学腔模式特性研究

微谐振腔模式特性研究是利用微腔研制新型光电器件的基础．为了研制出能采用平面工艺制作的定向输出的微腔激光器，文章采用解析和数值模拟方法深入研究了正三角形及正方形光学微腔的模式特性，并得到与数值模拟结果符合非常好的解析场分布及模式波长．对正方形光学微腔，把模式组合成满足正方形对称性的场分布，发现其类WG模式只存在品质因子比它小一个数量级以上的偶然简并模式，因此正方形微腔有利于实现真正的单模工作．     

Analysis of Mode Quality Factors for Equilateral Triangle Semiconductor Microlasers with Rough Sidewalls

The eigenmode characteristics for equilateral triangle resonator (ETR) semiconductor microlasers are analysed by the finite-difference time-domain technique and the Pade approximation.The random Gaussian correlation function and sinusoidal function are used to model the side roughness of the ETR.The numerical results show that the roughness can cause the split of the degenerative modes,but the confined modes can still have a high quality factor.For the ETR with a 3μm side length and the sinusoidal fluctuation,we can have a quality factor of 800 for the fundamental mode in the wavelength of 1500nm,as the amplitude of roughness is 75nm.     

Experimental study of mode characteristics for equilateral triangle semiconductor microcavities

Equilateral triangle semiconductor microcavities with tensile-strained InGaAsP multi-quantum-well as the active region are fabricated by the inductively coupled plasma (ICP) etching technique. The mode characteristics of the fabricated microcavities are investigated by photoluminescence, and enhanced peaks of the photoluminescence spectra corresponding to the fundamental transverse modes are observed for microcavities with side lengths of 5 and 10μm. The mode wavelength spacings measured experimentally coincide very well with those obtained by the theoretical formulae.