Measurement of fluorescence spectra and quantum yields of 193 nm ArF laser photoablation of the cornea and synthetic lenticules

摘要

Abstract: Photorefractive keratomileusis procedures are currently being evaluated for both direct ablation of the human cornea and for the shaping of synthetic lenticules, with the ArF excimer laser offering the promise of reduced photochemical damage of underlying tissues due to the non-penetrative nature of 193 nm radiation. In order to better consider the possible effects of any secondary luminescence produced by the interaction of 193 nm radiation with these materials, an optical system based on a gated diode array spectrometer was constructed and used to record their fluorescence spectra at known laser fluences. A broadband fluorescence peak centered around 290-330 nm was observed upon irradiation of corneal buttons and collagen-based biopolymers. The optical efficiency of the fluorescence cell was calibrated by the use of a scattering material of known reflectivity allowing estimates of the fluorescence quantum yield of this process to be made.!26