中国激光, 2009, 36 (2): 503, 网络出版: 2009-02-23
20 kHz扫频光学相干层析系统
Development of 20 kHz Swept Source Optical Coherence Tomography System
医用光学与生物技术 光学相干层析成像 扫频光源 波数校正 分辨率 medical optics and biotechnology optical coherence tomography swept source wave number caliberation resolution
摘要
研制了扫频光学相干层析技术(SS-OCT)系统。该系统基于快速扫频激光光源,将轴向扫描频率由原来时域光学相干层析技术(OCT)系统的500 Hz提高到20 kHz。采用了基于OCT系统本身的预标定方法,实现了波数空间的线性校正。针对扫频光源光谱的非高斯型分布,对干涉光谱实施了基于窗口函数的光谱整形。对于干涉光谱中的直流项和自相关项,除了采用平衡探测共模抑制外,还运用了减除平均值的软件处理方法。系统纵向分辨率14 μm,横向分辨率12 μm,在空气介质中的成像深度3.9 mm,利用研制的SS-OCT系统,成功实现了手指组织样品的快速OCT成像。
Abstract
The self-developed swept source optical coherence tomography (SS-OCT) system is reported. Based on a high speed scanning laser source, the system realizes high speed A-scan rate of 20 kHz from 500 Hz A-scan rate of time-domain OCT. To realize linear calibration of wave number space, a pre-calibration method based on the SS-OCT system is used. Because of the non-Gaussian spectrum output of the swept source, a method based on window function is used for spectrum reshaping in the spectrum domain. To eliminate the direct current(DC) and auto-correlation term in the interference spectrum, the common-rejection of balanced detection, and a software method of subtract the mean value were used. The axial and lateral resolution of the SS-OCT system achieves 14 μm and 12 μm, respectively. The ranging depth of the SS-OCT achieves 3.9 mm. High speed optical coherence tomography images of finger-pad organism using the SS-OCT system wera obtained.
吴彤, 丁志华. 20 kHz扫频光学相干层析系统[J]. 中国激光, 2009, 36(2): 503. Wu Tong, Ding Zhihua. Development of 20 kHz Swept Source Optical Coherence Tomography System[J]. Chinese Journal of Lasers, 2009, 36(2): 503.