摘要
We have investigated the transverse mode pattern and the optical field confinement factor of gallium nitride （GaN） laser diodes （LDs） theoretically. For the particular LD structure, composed of approximate 4 μm thick n-GaN substrate layer, the maximum optical confinement factor was found to be corresponding to the 5^th order transverse mode, the so-called lasing mode. Moreover, the value of the maximum confinement factor varies periodically when increasing the n-side GaN layer thickness, which simultaneously changes and increases the oscillation mode order of the GaN LD caused by the effects of mode coupling. The effects of the thickness and the average composition of Al in the AlGaN/GaN superlat.tice on the optical confinement factor are also presented. Finally, the mode coupling and optimization of the layers in the GaN-based LD are discussed.
We have investigated the transverse mode pattern and the optical field confinement factor of gallium nitride （GaN） laser diodes （LDs） theoretically. For the particular LD structure, composed of approximate 4 μm thick n-GaN substrate layer, the maximum optical confinement factor was found to be corresponding to the 5^th order transverse mode, the so-called lasing mode. Moreover, the value of the maximum confinement factor varies periodically when increasing the n-side GaN layer thickness, which simultaneously changes and increases the oscillation mode order of the GaN LD caused by the effects of mode coupling. The effects of the thickness and the average composition of Al in the AlGaN/GaN superlat.tice on the optical confinement factor are also presented. Finally, the mode coupling and optimization of the layers in the GaN-based LD are discussed.
基金
Project supported by the Wang Faculty Fellowship at Peking University,Beijing,China,2006-2007 through California State University (CSU) International Programs USA
the National Basic Research Program of China (Grant No 2007CB307004)
the National High Technology Research and Development Program of China (Grant No 2006AA03A113)
the National Natural Science Foundation of China (Grant Nos 60276034,60577030 and 60607003)
