与CT等传统医学诊断技术相比，光学相干层析（OCT）成像技术能够获得更高的空间分辨率，但也存在穿透深度不足的问题。近年来，长波长1.7µm超连续谱光源的出现增加了穿透深度，然而这类光源难以应用于扫频OCT系统，无法发挥扫频OCT对深层组织探测时的高灵敏度优势。针对这一问题，并考虑到现有扫频OCT光源的增益介质辐射波长受限的问题，项目利用硒化铅（PbSe）胶体量子点辐射波长调谐灵活、增益带宽大、制备成本低等多项优势，提出基于PbSe胶体量子点的长波长全光纤扫频OCT光源。采用数值模拟与实验研究相结合的思路，①探明光源的快速调谐动力学过程、明确谐振腔参数与光源输出特性的依赖关系，准确建立数值计算模型，为今后PbSe胶体量子点在全光纤扫频OCT光源领域的应用提供理论基础；②产生1.7µm宽带快速可调谐激光，可望用于OCT深层组织探测研究中。

Compared with computed tomography (CT) or other conventional medical diagnostic technologies, optical coherence tomography (OCT) offers the much higher spatial resolution, although its penetration depth is at present insufficient. Recently, the penetration depth of OCT has been improved through using supercontinuum source operating at a long wavelength of 1.7 µm, however, this sort of light source is not compatible with swept-source OCT (SS-OCT) systems. In this case, the SS-OCT ability of detecting deep tissues at a high sensitivity, is unavailable. To address this problem and another that the wavelengths emitted from frequency-swept laser sources are limited by their gain media, a long-wavelength operated all-fiber frequency-swept light source based on a gain medium of lead selenide (PbSe) colloidal quantum dots (CQDs) is proposed in this project, considering that PbSe CQDs have the advantages of tuning emission wavelength conveniently, broad gain bandwidth, low preparation cost, etc. By means of numerical simulation along with experimental investigation, (1) The dynamics of rapid tuning, as well as the relationship between the resonator parameters and the output properties of the light source, would be illuminated. After that, a mathematical model would be established accurately. These achievements obtained would be served as the theoretical basis while PbSe CQDs would be applied to the region of all-fiber light source of SS-OCT in the future. (2) 1.7 µm operated broadband rapid tunable laser would be obtained, and would be further applied to the field regarding the detection of deep biology tissues.