Ahsen Osman O, Tao Yuankai K, Potsaid Benjamin M, Sheikine Yuri, Jiang James, Grulkowski Ireneusz, Tsai Tsung-Han, Jayaraman Vijaysekhar, Kraus Martin F, Connolly James L, Hornegger Joachim, Cable Alex, Fujimoto James G
Department of Electrical Engineering & Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA.
Opt Express. 2013 Jul 29;21(15):18021-33. doi: 10.1364/OE.21.018021.
We demonstrate high speed, swept source optical coherence microscopy (OCM) using a MEMS tunable vertical cavity surface-emitting laser (VCSEL) light source. The light source had a sweep rate of 280 kHz, providing a bidirectional axial scan rate of 560 kHz. The sweep bandwidth was 117 nm centered at 1310 nm, corresponding to an axial resolution of 13.1 µm in air, corresponding to 8.1 µm (9.6 µm spectrally shaped) in tissue. Dispersion mismatch from different objectives was compensated numerically, enabling magnification and field of view to be easily changed. OCM images were acquired with transverse resolutions between 0.86 µm - 3.42 µm using interchangeable 40X, 20X and 10X objectives with ~600 µm x 600 µm, ~1 mm x 1 mm and ~2 mm x 2 mm field-of-view (FOV), respectively. Parasitic variations in path length with beam scanning were corrected numerically. These features enable swept source OCM to be integrated with a wide range of existing scanning microscopes. Large FOV mosaics were generated by serially acquiring adjacent overlapping microscopic fields and combining them in post-processing. Fresh human colon, thyroid and kidney specimens were imaged ex vivo and compared to matching histology sections, demonstrating the ability of OCM to image tissue specimens.
我们展示了一种使用微机电系统（MEMS）可调谐垂直腔面发射激光器（VCSEL）光源的高速扫频源光学相干显微镜（OCM）。该光源的扫描速率为280 kHz，提供双向轴向扫描速率为560 kHz。扫描带宽为117 nm，中心波长为1310 nm，对应于空气中13.1 µm的轴向分辨率，在组织中对应于8.1 µm（光谱整形后为9.6 µm）。通过数值补偿不同物镜的色散失配，使得放大倍数和视野能够轻松改变。使用可互换的40X、20X和10X物镜分别以0.86 µm - 3.42 µm之间的横向分辨率采集OCM图像，视野分别为600 µm x 600 µm、1 mm x 1 mm和~2 mm x 2 mm。通过数值校正光束扫描时路径长度的寄生变化。这些特性使扫频源OCM能够与广泛的现有扫描显微镜集成。通过连续采集相邻重叠的微观视野并在后期处理中进行组合，生成了大视野镶嵌图。对新鲜的人类结肠、甲状腺和肾脏标本进行了离体成像，并与匹配的组织学切片进行了比较，证明了OCM对组织标本成像的能力。
