title: Laser ablation of discs of agar gel.
abstract: Discs of agar gel mixed with ink were used to study ablation effects with an argon laser as a light source. Varying amounts of ink were added resulting in a variation of the attenuation coefficient between 0.45 and 6.3 mm-1. For laser beam irradiation horizontally incident on a vertical sample, the average velocity of ablation was found to be approximately constant for thicknesses up to 1.7 mm. When the laser beam was directed vertically on a sample held horizontally, the vaporized debris present in the beam attenuated the incident laser energy to such a degree that the average ablation velocity decreased by a factor of approximately five. Horizontal beam experiments for various attenuation coefficients showed that an attenuation coefficient of about 1.7 mm-1 is optimal for fast penetration of discs thicker than 4 mm. Thus, based upon the optical properties of a given tissue, there may exist an optimum laser wavelength to maximise ablation velocity.
authors.affiliation: Biomedical Engineering Program, University of Texas at Austin 78712.
authors.forename: S
authors.initials: S
authors.lastname: Rastegar
authors.forename: M J
authors.initials: MJ
authors.lastname: van Gemert
authors.forename: A J
authors.initials: AJ
authors.lastname: Welch
authors.forename: L J
authors.initials: LJ
authors.lastname: Hayes
mesh_terms: D000362:Agar; D001161:Arteriosclerosis / Q000601:surgery; D006801:Humans; D053685:Laser Therapy; D008954:Models, Biological; D013927:Thrombosis / Q000601:surgery
chemical_list: D000362:Agar