Real-time delivery and monitoring of endoscopic laser therapy using a double clad fiber in an optical coherence tomography system

We present a system for the real-time delivery and monitoring of laser therapy using an optical coherence tomography system with a double clad fiber (DCF). The therapy laser, guided through the DCF outer cladding, is used to coagulate the tissue of interest, while the single-mode core is used to perform real-time cross-sectional monitoring of the therapy. The therapy monitoring is based on the analysis of the temporal fluctuation of the OCT intensity speckle pattern. A novel intensity-based analysis of the OCT signal is robust against phase instability and motion artifacts of endoscopic systems, while the integrated DCF enables a straightforward implementation in catheter probes.