Laser tissue coagulation and concurrent optical coherence tomography through a double-clad fiber coupler

Double-clad fiber (DCF) is herein used in conjunction with a double-clad fiber coupler (DCFC) to enable simultaneous and co-registered optical coherence tomography (OCT) and laser tissue coagulation. The DCF allows a single channel fiber-optic probe to be shared: i.e. the core propagating the OCT signal while the inner cladding delivers the coagulation laser light. We herein present a novel DCFC designed and built to combine both signals within a DCF (>90% of single-mode transmission; >65% multimode coupling). Potential OCT imaging degradation mechanisms are also investigated and solutions to mitigate them are presented. The combined DCFC-based system was used to induce coagulation of an ex vivo swine esophagus allowing a real-time assessment of thermal dynamic processes. We therefore demonstrate a DCFC-based system combining OCT imaging with laser coagulation through a single fiber, thus enabling both modalities to be performed simultaneously and in a co-registered manner. Such a system enables endoscopic image-guided laser marking of superficial epithelial tissues or laser thermal therapy of epithelial lesions in pathologies such as Barrett's esophagus. (C) 2015 Optical Society of America

在此，双包层光纤（DCF）与双包层光纤耦合器（DCFC）结合使用，以实现光学相干断层扫描（OCT）和激光组织凝固的同步且配准的操作。双包层光纤允许共享单通道光纤探头：即纤芯传输OCT信号，而内包层传输凝固激光。在此我们介绍一种新型的双包层光纤耦合器，其设计和制造用于在双包层光纤内合并两种信号（单模传输>90%；多模耦合>65%）。还研究了可能导致OCT成像质量下降的机制，并提出了缓解这些问题的解决方案。基于双包层光纤耦合器的组合系统被用于诱导离体猪食管的凝固，从而能够实时评估热动力学过程。因此，我们展示了一种基于双包层光纤耦合器的系统，该系统通过单根光纤将OCT成像与激光凝固相结合，从而能够以同步且配准的方式实现两种模式。这样的系统能够在内窥镜图像引导下对浅表上皮组织进行激光标记，或者对诸如巴雷特食管等病症中的上皮病变进行激光热疗。（C）2015美国光学学会