光泵浦低阈值聚合物激光器

Low Threshold Polymer Lasers Under Optical Pumping

高阈值是实现直接电驱动聚合物激光器的主要障碍。本文采用性能优异的蓝光材料-聚芴(PFO)作为激光增益介质,根据腔量子电动力学原理,设计出结构合理的平面光学微腔,通过减薄聚合物层厚度的方法进一步降低有源层材料自吸收;采用两种不同材料体系的分布布拉格反射镜(DBR)构筑光学微腔,减小顶部DBR制备过程中引入的额外光损耗,获得了低损耗、高Q值的光学谐振腔;有效调控PFO的自发发射和受激发射特性,最终实现了峰值波长位于443 nm、阈值仅为30 mW/cm^2的光泵浦低阈值聚合物激光器。

High threshold is the main obstacle to achieving direct electrically pumped polymer lasers.In this paper,high-performance blue light material,polyfluorene(PFO)is used as a laser gain medium.A planar optical microcavity with appropriate structure is designed based on cavity quantum electrodynamics principle.The self-absorption of active layer material is further reduced by lowing the thickness of polymer layer.Optical microcavity is constructed by DBRs with two different material system.The extra optical loss is cut down in the preparation process of top DBR,and the optical resonator with low loss and high Q value is finally obtained.An optically pumped low threshold polymer laser with a peak wavelength of 443 nm and a threshold of only 30 mW/cm^2 is realized by effectively controlling the spontaneous emission and stimulated emission characteristics of PFO.