Optical coherence tomography-surveilled laser ablation using multifunctional catheter and 355-nm optical pulses

An optical coherence tomography (OCT)-monitored laser ablation system is presented in this study. The laser ablation subsystem is constructed using the third harmonic output of a Nd:YAG laser source operating at a 355-nm optical wavelength with a single pulse energy greater than 160 mJ and a 1–10 Hz tunable repetition rate. The imaging subsystem is a typical M-mode swept-source OCT system. Moreover, a type of all-fiber multifunctional integrated catheter is demonstrated. The ablation catheter consists of a fiber bundle including 41 multi-mode fibers with an outer diameter of 0.9 mm. A forward-viewing OCT imaging probe is inserted into the ablation catheter for M-mode imaging. The performance of the system is demonstrated by OCT surveillance of the laser ablation process using expanded polystyrene foam as the sample. The OCT system can be used to record the ablation process and simultaneously count the laser ablation duration. This study proposes an effective potential technique to surveil material laser ablation processes, especially in situations where bulky optics are prohibited and all-fiber devices are required.