半导体量子点与石英光纤集成的宽谱光放大器研究

In order to solve problem of narrow gain band width, regular gain wavelength, slow response speed and long active optical fiber of the existing fiber amplifier doped of rare earth,this project proposes coating taper region of optical fiber coupler with semiconductor quantum dot doped material to realize a kind of wide spectrum optical amplifier through the evanescent field excitation, which integrated by semiconductor quantum dot and the quartz optical fiber. Main research contents include: physical model of integrated semiconductor quantum dot optical fiber amplifier; sol-gel doping technique of semiconductor quantum dots; coating process and structure optimization design of thin films doped of quantum dot in the fused-tapered zone; wide spectrum and high speed response characteristics of semiconductor quantum dots fiber amplifier. Semiconductor quantum dot has quantum size effect. It can realize functions of wide spectrum, tunalbe wavelength and high speed optical amplification. Optical fiber coupler based on the common quartz optical fiber has low loss. Therefore, the project based on mixing semiconductor quantum dot and common quartz fiber material, explores a novel optical fiber amplifier technology, to meet the needs of broadband, high speed communication and optical access network development.

本项目提出将半导体量子点掺杂材料涂覆于石英光纤耦合器的锥区，通过渐逝波场激发量子点，实现一种半导体量子点与石英光纤集成的宽谱光放大器，拟解决现有稀土掺杂光纤放大器放大谱宽窄、增益波段固定、响应速度慢、有源光纤长等问题。项目主要研究内容包括：集成半导体量子点光纤放大器的物理模型；半导体量子点的溶胶-凝胶掺杂技术；量子点掺杂薄膜在熔锥区的涂覆工艺和结构优化设计；半导体量子点光纤放大器的宽光谱、高速响应特性。半导体量子点具有量子尺寸效应，可实现宽光谱、波段可调、高速响应的光放大功能；光纤耦合器是基于常规石英光纤，具有低损耗的光传输性能，因此，本项目基于这种将半导体量子点与常规石英光纤材料进行混合集成的思想，探索一种新型光纤放大技术，以满足宽带、高速光纤通信和光接入网发展的需求。

本项目提出了将PbS半导体量子点掺杂溶胶凝胶涂覆于熔锥光纤锥区，通过渐逝波场激发量子点，实现了一种半导体量子点与石英光纤集成的宽谱光放大器，该放大器具有增益带宽宽、单位增益高、结构紧凑等优点。项目主要取得了如下成果：建立了量子点锥形光纤放大器的理论模型，并对量子点锥形光纤放大器的结构设计和性能进行了理论分析；研究了基于溶胶-凝胶PbS量子点合成技术，并通过甲基掺杂实现了降低溶胶折射率、与石英光纤折射率匹配的目的；以980nm半导体激光器作为泵浦光，实现了在1310nm波段的超宽带光放大器，放大器长度约2cm（锥区），放大光谱范围大于200nm，增益达10dB，单位长度增益大于4dB/cm；为了增强渐逝波激发量子点的浓度，提出了熔锥光纤渐逝波光场吸附半导体量子点技术，利用光对微纳粒子的吸附作用，将PbS量子点均匀的吸附在熔锥光纤锥区表面，大大提升了与熔锥光纤渐逝波相互作用的量子点浓度。因此，本项目基于这种将半导体量子点与常规石英光纤材料进行混合集成的思想，探索了一种新型光纤放大技术，以满足宽带、高速光纤通信和光接入网发展的需求。