Possibilities for organizing feedback on the Doppler backscattering signal in surgical СО2 lasers

Generation characteristics and possibilities of autodyne reception in single-mode CO2 lasers with pulse-periodic pumping of the active medium used in laser medical installations were studied. The objects of study were the following CO2 lasers: Diamond C-30 by Coherent (USA); 48-2W by Synrad (USA); D-30 by Davi (China). It is shown that the СО2 laser D-30 has the highest long-term radiation stability with significantly low short-term radiation stability (39 ± 10%). The CO2 laser 48-2W has the highest short-term radiation stability (0.62%). The amplitude-frequency characteristics and features of autodyne reception of backscattered radiation for these lasers were studied. The possibility of registration of backscattered radiation by autodyne detection in the process of laser dissection of fat and muscle tissue of a pig in vitro was studied. The obtained results can be used for the development of smart laser surgical systems with feedback.