Pulsed ultraviolet laser ablation: Theoretical considerations and applications in medicine
Date
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Pulsed ultraviolet lasers can be used to induce clean etching in organic and some inorganic materials. This effect is called photoablation or ablative photodecomposition. Although the precise cause remains unknown, this phenomenon is becoming of vital importance in micromachining, materials processing, and medicine.
To better understand the photoablation process, a theoretical description of the process has been developed. This description is based on a treatment of the radiation transport of intense ultraviolet light pulses through absorbing organic material. The theory predicts deviations from Beer's Absorption Law at high intensities which are in fact observed. These discrepancies are due to three main effects: saturation of the finite number of chromophores in the material, multiphoton absorption, and attenuation of laser light by ablation products. Using the analysis to model the ablation process it is possible to describe observed ablation behaviors for a variety of synthetic and biological substrates.
Excimer laser photoablation has also been studied experimentally as a means of removing occlusive arterial thrombi. Thrombi induced in canine coronary arteries were removed with XeF excimer laser light (351 nm) delivered via flexible optical fiber. The results of this study indicated that it was possible to remove significant thrombi (27 mg mass) within 3 minutes, without causing injury to the adjacent arterial wall. In addition, the ablation products consisted of a minute volume of gas and small particulate debris ($>$100
Description
Advisor
Degree
Type
Keywords
Citation
Pettit, George H.. "Pulsed ultraviolet laser ablation: Theoretical considerations and applications in medicine." (1990) Diss., Rice University. https://hdl.handle.net/1911/16381.