掺杂光子晶体光纤自发辐射与掺杂激活杂质的光增益透射谱研究

Study on the Optical Gain of Photonic Crystals Fiber with Active Impurity

借助光子晶体中二能级原子的自发辐射理论证明缺陷态的局域场存在的必然性以及局域场基本性质,为研究光子晶体光纤掺杂自发辐射的内在规律提供了理论依据。且将自发辐射理论与数值模拟相结合,在缺陷介质中掺激活杂质时,研究了光子晶体光纤的掺杂局域场特征以及受激辐射增强和透射率大于1现象与光子带隙群速度异常和掺杂层复有效折射率成负的虚部之间的内在关系。由此说明光子晶体光纤的缺陷介质中掺入激活杂质时,光子禁带中能出现品质因子非常高的杂质态,具有很大的态密度,较强的受激辐射放大。

Basing on the theory of spontaneous emission from two-level atoms in photonic crystal fibers （PCFs） , we demonstrated the inevitable existence of localized fields of defect modes as well as their basic properties. It provides theoretical proof for inevstingating into the inherent laws of spontaneous radiation from doped media. On the basis, the relation between the enhancement of stimulated emission as well as transmissivity being greater than one and the abnormal group velocity in photonic band gaps as well as negative imaginary part of the complex effective index of refraction of doped defect layer is studied by numerical simulation method. Therefore great amplification of stimulated emission is obtainablel.