Megahertz OCT for ultrawide-field retinal imaging with a 1050nm Fourier domain mode-locked laser
Megahertz OCT for ultrawide-field retinal imaging with a 1050nm Fourier domain mode-locked laser
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DOI：
10.1364/oe.19.003044
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发表时间：
2011-02-14
期刊：
影响因子：
3.8
通讯作者：
Huber, Robert
中科院分区：
文献类型：
--
作者：
Klein, Thomas;Wieser, Wolfgang;Huber, Robert
我们演示了使用傅立叶域锁模（FDML）激光器的高速扫频源视网膜OCT成像。该激光器使用半导体光放大器和掺镱光纤放大器的组合，提供超过50mW的输出功率。1050 nm FDML激光器使用标准电信光纤作为公里长的延迟线，而不是两个数量级更昂贵的真实的单模光纤。我们研究了这种“寡模”光纤对FDML激光器性能的影响。研究了每秒684，400次和1，368，700次轴向扫描的两种设计配置，比目前的商业仪器快25倍和50倍，比以前的单点眼科结果快4倍以上。这些高速度使得能够在几秒钟内采集密集采样的视网膜超宽视场数据集。使用不同的设置，仅在3秒和6秒内就可以获得由1900 x 1900 A扫描组成的超宽场数据，其视角类似于70度。这样的OCT数据集，比以前报道的大一倍以上，被折叠成4百万像素的高清晰度眼底图像。我们通过激光输出的硬件光谱整形实现了对脉络膜的良好穿透。在组织中的轴向分辨率为12 μ m（684kHz）和19 μ m（1.37MHz）。一系列新的数据处理和成像提取协议，使超宽场各向同性数据集，提出。密集各向同性采样使得能够实现沿着沿着任意坐标的横截面图像和深度分辨的正面眼底图像。此外，我们研究如何各向同性平均相比，平均横截面沿着慢轴。(C)2011年美国光学学会
We demonstrate ultrahigh speed swept source retinal OCT imaging using a Fourier domain mode locked (FDML) laser. The laser uses a combination of a semiconductor optical amplifier and an ytterbium doped fiber amplifier to provide more than 50mW output power. The 1050nm FDML laser uses standard telecom fiber for the km long delay line instead of two orders of magnitude more expensive real single mode fiber. We investigate the influence of this "oligo-mode" fiber on the FDML laser performance. Two design configurations with 684,400 and 1,368,700 axial scans per second are investigated, 25x and 50x faster than current commercial instruments and more than 4x faster than previous single spot ophthalmic results. These high speeds enable the acquisition of densely sampled ultrawide-field data sets of the retina within a few seconds. Ultrawide-field data consisting of 1900 x 1900 A-scans with similar to 70 degrees degrees angle of view are acquired within only 3 and 6 seconds using the different setups. Such OCT data sets, more than double as large as previously reported, are collapsed to a 4 megapixel high definition fundus image. We achieve good penetration into the choroid by hardware spectral shaping of the laser output. The axial resolution in tissue is 12 mu m (684kHz) and 19 mu m (1.37MHz). A series of new data processing and imaging extraction protocols, enabled by the ultrawide-field isotropic data sets, are presented. Dense isotropic sampling enables both, cross-sectional images along arbitrary coordinates and depth-resolved en-face fundus images. Additionally, we investigate how isotropic averaging compares to the averaging of cross-sections along the slow axis. (C) 2011 Optical Society of America