OCT超宽带窄瞬时线宽扫频方法研究

项目名称： OCT超宽带窄瞬时线宽扫频方法研究

项目编号： No.61308115

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 陈明惠

作者单位： 上海理工大学

项目金额： 27万元

中文摘要： 针对现有OCT扫频光源的单个调谐滤波器自由光谱范围和光谱分辨率互相权衡、互相制约的问题，本项目提出组合调谐滤波技术，研究OCT扫频光源同时获得超宽带、高光谱分辨率(窄瞬时线宽)的线性扫频方法,实现高轴向分辨率大成像深度的光学频域OCT成像。组合调谐滤波方法采用由自由光谱范围宽、光谱分辨率低的低刻线光栅/多面镜调谐滤波器和工作在非谐振条件下的自由光谱范围窄、光谱分辨率高的法布里珀罗调谐滤波器级联而成。设计组合型调谐滤波器，兼备宽的自由光谱范围和高光谱分辨率双重优势。研究动态模式激光振荡机制，解决瞬态激光建立振荡的关键技术问题。基于组合型调谐滤波器的1300 nm 波段的OCT扫频激光光源系统可实现扫频光谱范围为170 nm以上，瞬时线宽可达到0.03 nm以上，基于该扫频光源平台的OCT成像可望达到组织轴向分辨率为4.6 μm。

中文关键词： 光学相干层析成像；光学频域成像；扫频光源；组合型调谐滤波器；激光

英文摘要： Reviewing existing tunable filters, there is a trade-off between the bandwidth and the instantaneous line-width in a single tunable filter. In this study, a novel ultra-broad tunable bandwidth and narrow instantaneous line-width swept laser source using combined tunable filters for high axial resolution and large imaging range optical coherence tomography（OCT）is proposed. The combined tunable filters are realized by cascading two filters including a fiber Fabry-Perot tunable filter driven at a non-resonant frequency and a tunable filter based on low groove density grating with scanning polygon mirror. In this way,the broad bandwidth and the narrow instantaneous line-width can be obtained simultaneously. The mechanism of laser oscillation in the dynamic mode and the key technique in establishment of transient laser oscillation is investigated. The swept laser based on combined tunable filters working at 1300 nm wavelength can provide a tuning range of 170 nm resulting in an axial resolution of 4.6 μm in tissue. The instantaneous line-width can be smaller than 0.03 nm.

英文关键词： optical coherence tomography；optical frequency domain imaging；swept source；combined tunable filters；laser