National Kaohsiung Normal University, Department of Optoelectronics & Communication Engineering, Kaohsiung 802, Taiwan.
J Biomed Opt. 2014 Feb;19(2):21110. doi: 10.1117/1.JBO.19.2.021110.
A swept source (SS)-based circular-state (CS) polarization-sensitive optical coherence tomography (PS-OCT) constructed entirely with polarization-maintaining fiber optics components is proposed with the experimental verification. By means of the proposed calibration scheme, bulk quarter-wave plates can be replaced by fiber optics polarization controllers to, therefore, realize an all-fiber optics CS SSPS-OCT. We also present a numerical dispersion compensation method, which can not only enhance the axial resolution, but also improve the signal-to-noise ratio of the images. We demonstrate that this compact and portable CS SSPS-OCT system with an accuracy comparable to bulk optics systems requires less stringent lens alignment and can possibly serve as a technology to realize PS-OCT instrument for clinical applications (e.g., endoscopy). The largest deviations in the phase retardation (PR) and fast-axis (FA) angle due to sample probe in the linear scanning and a rotation angle smaller than 65 deg were of the same order as those in stationary probe setups. The influence of fiber bending on the measured PR and FA is also investigated. The largest deviations of the PR were 3.5 deg and the measured FA change by ~12 to 21 deg. Finally, in vivo imaging of the human fingertip and nail was successfully demonstrated with a linear scanning probe.
一种完全基于保偏光纤光学元件的扫频源（SS）-圆偏振态（CS）偏振敏感光相干断层扫描（PS-OCT）系统被提出并进行了实验验证。通过所提出的校准方案，可以用光纤偏振控制器代替块状 quarter-wave 板，从而实现全光纤 CS SSPS-OCT。我们还提出了一种数值色散补偿方法，不仅可以提高轴向分辨率，还可以提高图像的信噪比。我们证明，这种紧凑便携的 CS SSPS-OCT 系统具有与块状光学系统相当的精度，需要的镜头对准精度更低，并且可以作为一种实现用于临床应用（例如内窥镜）的 PS-OCT 仪器的技术。在线性扫描中，由于样品探头引起的相位延迟（PR）和快轴（FA）角度的最大偏差以及小于 65 度的旋转角度与固定探头设置的偏差相同。还研究了光纤弯曲对测量的 PR 和 FA 的影响。PR 的最大偏差为 3.5 度，测量的 FA 变化约为 12 到 21 度。最后，成功地用线性扫描探头对人指尖和指甲进行了体内成像。
