【作者】 陈金强；

【导师】 薄报学；

【作者基本信息】 长春理工大学 ， 光学， 2008， 硕士

【摘要】 在光电子通讯领域,围绕大功率、近衍射极限半导体激光光源,研究人员设计并制作了多种激光器结构。主振功率光放大器(MOPA),由于其高质量的光束输出,成为研究人员优先考虑的一种典型器件结构。本文针对直腔脊形波导、分布反馈或分布布拉格反馈作为主振半导体激光器与锥形放大器单片集成的主振光放大器的缺点,提出制作出结构简单,制作工艺难度低的半环形半导体激光器与锥形放大器集成的主振功率光放大器,有利于避免主振半导体激光器对光放大器的影响,同时保证激光的输出模式质量、稳定性、可靠性。本文从泊松方程、载流子连续性方程、薛定谔方程及亥姆霍兹方程出发,通过数值求解得出激光器的阈值电流。简单分析了曲率半径对阈值电流密度的影响。为了实现较低的阈值电流,要求半环形腔的曲率半径选择在150μm左右。同时通过对弯曲波导方程的求解,简单分析了曲率半径对基侧模光场分布的影响。最后,针对传统湿法腐蚀存在的一些不足,本文提出采用光辅助刻蚀方法来实现脊形条的垂直刻蚀。用UV-LED作为光源并通过改变电压实现了n型衬底的边向角刻蚀θ的可控,也实现了p型衬底(110)—B面的垂直刻蚀,并采用光化学液相次序选择腐蚀的新方法,提高了表面的均匀性。更多还原

【Abstract】 Various laser diodes have been designed and developed for high-power,near diffraction-limit laser output in the field of optoelectronics.Master Oscillator Power Amplifiers(MOPA) are typical devices adopt by researchers for its high quality laser beam output potential.To overcome the drawback of distributed feedback laser diodes(DFB-LDs) used as the master oscillator(MO) laser,half-ring cavity is proposed as the MO for its simple fabrication process and potential to prevent interfering with each other of MO and PA. High quality of output beam,high reliability may be realized with the new designed MOPA.In this paper,we have analyzed the properties of the half-ring cavity laser with the Poisson equation,the electron and hole rate equation,the Schr(?)dinger equation and the Helmholtz equation.The threshold current of the half-ring laser was computed and the relationship between the curvature radius and the threshold current densities was analyzed. The curvature radius was set around 150μm for a low threshold current density.Meanwhile, we have solved the Helmholtz equation in the curved waveguides and analyzed the relationship between the curvature radius and the optical field-intensity of the fundamental lateral mode.A light-assisted etching method was adopted to realize vertical etching.We can control the sidewall angleθin n-type bulk GaAs by changing the operation voltage of UV-LED, and realize vertical etching along(110)—B plane in p-type bulk GaAs.Furthermore,a laser-assisted wet order-selective-etching new method is proposed,which smoothes the etched surface effectively.更多还原