较高掺杂浓度下CdSe/ZnS量子点光纤光致荧光光谱

制备了一种较高浓度掺杂的CdSe/ZnS量子点掺杂光纤.测量了不同掺杂浓度和不同光纤长度下的量子点光纤光致荧光光谱,得剑了荧光峰值增益最大时的量子点掺杂浓度和光纤长度.与低浓度掺杂光纤相比,较高掺杂浓度光纤中的荧光峰值光强明显提高.荧光峰值光强随光纤长度的变化在短距离内(L<1 cm)急剧上升,之后缓慢均匀下降.波长473 nm激励光强随光纤}乏度的变化呈指数形式衰减,消光系数为0.26～1.02 cm-1.在给定激励光强和激励波长的条件下,光纤中可达到最大荧光辐射的晕子点总数为一恒量.光纤中的荧光峰值波长存在红移,红移大小约8～15 nm,红移量与掺杂浓度以及光纤长度有关.这些实验结果可为今后量子点光纤放大器的研制提供参考.

Photoluminescence Spectra of CdSe/ZnS-Quantum Dot Doped Fiber with High Doping Concentrations

Optical fibers doped with highly concentrated CdSe/ZnS quantum dot (QD) are prepared, and their photoluminescence (PL) spectra are measured. The doping concentration and the fiber length, corresponding to the maximum PL peak, are determined by analyzing the respective PL spectrum. Compared with low doping concentrations, the observed peak intensities enhance greatly within 1 cm fiber length, and decrease gradually as the fiber length increases. The exciting intensity at 473 nm shows an exponential attenuation with an extinction coefficient of 0.26～1.02 cm~(-1). Given the exciting intensity and the exciting wavelength, the total amount of QD that can be added to obtain the maximum PL emission is a constant. A red shift of the PL-peak wavelength reaches to 8～15 nm, depending on the doping concentration and the fiber length. These results provide a reference in the development of possible quantum dot-doped fiber amplifiers in the future.