Laser-tissue interaction with a high-power 2-μm fiber laser: Preliminary studies with soft tissue

Background and Objective: Recent developments in fiber laser technology have introduced highly efficient, compact sources with high output beam quality. The first laser-tissue interaction studies with a high-power 2-μm fiber laser were conducted. Study Design/Materials and Methods: Chicken breast and porcine muscle tissue samples were subjected to continuous wave (cw) irradiation at 800-mW and 5-W output power levels, with spot sizes of approximately 150 μm. After laser irradiation, samples were inspected with an optical microscope and prepared for histologic processing. Results: Evaluation of surface changes in tissue samples indicated an interaction similar in nature to those previously demonstrated with other cw lasers, but with photothermal ablation characteristics typical of strongly absorbed lasers operating in the infrared wavelength region. An ablation velocity of 0.27 mm·sec^-1 in porcine tissue was determined at 800-mW incident power. Histopathologic analysis demonstrated the formation of lesions with minimal damage at boundaries and no evidence of carbonization. Conclusions: Results indicate that this fiber laser has the potential to fulfill applications in the medical field.