Wavelength dependence of femtosecond laser ablation threshold of corneal stroma.
We measure the surface ablation threshold fluence of porcine corneal stroma for 100 fs laser pulses, with wavelengths between 800 nm and 1450 nm, generated by a Ti:sapphire-pumped optical parametric amplifier. The ablation threshold was found to vary only slightly within this wavelength range, between 1.5 and 2.2 J/cm(2). The data suggest a rapid increase of the ablation threshold for wavelengths up to about 1000 nm, followed by a plateau for longer wavelengths. This behavior is partly confirmed by a simple theoretical model of the ablation process. The influence of the wavelength on the physics of surface ablation is discussed on the basis of the model.
Institut National de la Recherche Scientifique - Energie, Matériaux et Télécommunications,1650, boulevard Lionel-Boulet, Varennes, QC, J3X 1S2, Canada.
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Olivié
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Giguère
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Vidal
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Ozaki
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Kieffer
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Nada
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Brunette
D000818:Animals; D003198:Computer Simulation; D003319:Corneal Stroma / Q000033:anatomy & histology / Q000502:physiology* / Q000601:surgery*; D048988:Corneal Surgery, Laser / Q000379:methods*; D004056:Differential Threshold / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D066298:In Vitro Techniques; D008954:Models, Biological; D011829:Radiation Dosage; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013552:Swine