Performance analysis of a liquid lens for laser ablation using OCT imaging

• Chunqi Zhang, Xu Tang, Mingxuan Yang, Han Zhao, and Dong Sun
• received 03/28/2024; accepted 05/02/2024; posted 05/02/2024; Doc. ID 525094
• Abstract: Laser ablation has been used in different surgical procedures to perform precise treatments. Compared with previousfree-beam laser delivery systems, flexible optical fiber-based systems can deliver laser energy to a curved space, avoidingthe requirement of a straight working path to the target. However, the fiber tip maintains direct contact with the tissue toprevent laser divergence, resulting in fiber damage, uneven ablation, and tissue carbonization. Here, a liquid lens is usedto address the problem of laser defocusing when radiating targets at different depths for flexible optical fiber-basedsystems. The liquid lens focuses a laser with a maximum power of 3 W onto a medium-density fiberboard at a focal lengthof 40 mm-180 mm. The relationships between the ablation crater diameter and depth with the radiation time and laserpower have been quantitatively evaluated through OCT (optical coherence tomography) imaging. Experimentsdemonstrate that the liquid lens can continuously focus the high-power laser to different depths, with the advantages ofcompact size, fast response, light weight, and easy operation. This study explores liquid lens-based focused laser ablation,which can potentially improve the performance of future medical image-guided laser ablation.