介电体超晶格的研究

Dielectric superlattices

介电体超晶格是一种新型的有序微结构材料.它具有通常均质材料所不具有的独特优异性能,展现出重要的应用前景.文章介绍了南京大学研究组关于介电体超晶格研究所取得的进展,如将多个光参量过程集成于一块介电体超晶格之中获得了多波长激光同时输出,研制成超晶格全固态三基色激光器原型,在介电体超晶格中将拉曼散射强度增强到104—105倍,用超晶格研制的器件填补了体波超声器件从几百MHz到几千MHz的空白频段,发现了微波与超晶格振动的强烈耦合以及极化激元(polariton)的激发与传播等.

A dielectric superlattice is a type of material with an ordered microstructure. A series of results in this field have been obtained by our research group in Nanjing University. We proposed the theory of multiple quasi-phase-matching （QPM） , developed all-solid-state lasers operating at multi-frequencies as well as white-light lasers, discovered a QPM enhanced optical scattering effect, and a new mechanism for optical bistability. We have also studied piezoelectric ultrasonic excitation and prepared bulk prototype ultrasonic devices working at frequencies from several hundreds megahertz to a few gigahertz, discovered the strong coupling between superlattice vibrations and microwaves, and investigated the excitation and propagation of polaritons.