Temperature alterations of infrared light absorption by cartilage and cornea under free-electron laser radiation.
Like pure water, the water incorporated into cartilage and cornea tissue shows a pronounced dependence of the absorption coefficient on temperature. Alteration of the temperature by radiation with an IR free-electron laser was studied by use of a pulsed photothermal radiometric technique. A computation algorithm was modified to take into account the real IR absorption spectra of the tissue and the spectral sensitivity of the IR detector used. The absorption coefficients for several wavelengths within the 2.9- and 6.1-microm water absorption bands have been determined for various laser pulse energies. It is shown that the absorption coefficient for cartilage decreases at temperatures higher than 50 degrees C owing to thermal alterations of water-water and water-biopolymer interactions.
Institute of Laser and Information Technologies of the Russian Academy of Sciences, Troitsk 14210, Russia. sobol@laser.ru
Emil N
EN
Sobol
Alexander P
AP
Sviridov
Moishe S
MS
Kitai
Glenn S
GS
Edwards
D000818:Animals; D002356:Cartilage / Q000528:radiation effects*; D002417:Cattle; D003315:Cornea / Q000528:radiation effects*; D007259:Infrared Rays; D007834:Lasers; D013696:Temperature