An efficient phase analysis-based wavenumber linearization scheme for swept source optical coherence tomography systems
An efficient phase analysis-based wavenumber linearization scheme for swept source optical coherence tomography systems
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DOI：
10.1088/1612-2011/12/5/055601
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发表时间：
2015-05-01
影响因子：
1.7
通讯作者：
Seah, L. K.
中科院分区：
文献类型：
--
作者：
Meleppat, R. K.;Matham, M. V.;Seah, L. K.
本文报道了一种有效的基于相位分析的直接时域重采样方案，用于扫描源光学相干层析成像（SS-OCT）系统。从Mach-Zehnder干涉仪产生的校准信号中提取出代表激光非线性扫频的解包裹相位值。等距波数空间是通过将得到的相位值归一化，然后缩放到最大采样点数来计算的。为了消除现有基于相位的时域重采样方法中使用的多项式拟合方法，直接从线性器坐标中计算出与均匀分布的相位值相对应的非均匀分数阶时间指标值。与现有的主要线性化方案相比，所提出的线性化方案在精度和速度方面都有了显著的提高。该算法的鲁棒性，以及它对分辨率和灵敏度的影响，通过内部开发的SS-OCT系统，并通过对人类指甲和眼睛模型进行成像作为测试样本来说明。
This letter reports an efficient phase analysis-based direct time domain resampling scheme for swept source-based optical coherence tomography (SS-OCT) systems. The unwrapped phase values, representing non-linear frequency sweeping of the laser, are extracted from the calibration signal generated by a Mach-Zehnder interferometer. Equidistant wavenumber spaces are calculated by normalizing obtained phase values followed by scaling to the maximum number of sampling points. The non-uniform fractional time index values corresponding to the uniformly distributed phase values are computed directly from the linearizer coordinates in order to eliminate the use of the polynomial fitting approach that is used in existing phase-based time domain resampling methods. This proposed linearization scheme shows a significant improvement in performance in terms of accuracy and speed in comparison with the major existing schemes. The robustness of the algorithm, as well as its impact on the resolution and sensitivity, are illustrated using an in-house-developed SS-OCT system and by performing imaging of a human finger nail and an eye model as test samples.