离子晶体量子线中的非线性极化激元

NONLINEAR POLARITONS IN A QUANTUM WIRE MADE OF IONIC CRYSTAL

讨论了离子晶体量子线中的非线性极化激元的色散关系 .由于量子线对电磁波场的尺寸限制作用及原胞中离子间的非线性相互作用 ,使离子晶体量子线中的非线性极化激元的色散关系相对于体材料有 2点值得注意 :在ωTO以下及ωL O以上区域 ,在波矢 k小的区域 ,频率值向上移动 ,在原频率禁区ωTO<ω<ωL O中 ,由于非线性效应引起的新的极化激元的频率分支则与体材料基本一致 ,即尺寸效应不显著 ,这意味着在量子线中会有与体材料中相同的光孤立子的传输特性 .

The dispersion relation of nonlinear polaritons in a quantum w ire made of an ionic crystal is discussed. Due to the confinement of the quantum wir e and the nonlinear interactions between ions of a primitive cell, the dispersio n relation of the nonlinear polaritons of the quantum wire will be diffrent from that of a bulk material. Two points should be noted. Firstly, the frequencies o f the polaritons will be larger than that of a linear bulk material below ω TO and over ω LO; secondly, the new frequency branch originated from the nonlinear effects in the region ω TO<ω<ω LO is similar to that of the nonlinear bulk material. Accordingly similar optical solitons can be obtained in a quantum wire.