Patent ID: 7522270

Claim:
A method of determining an extent of irreversible radiation damage of an optical material, said method comprising the steps of: a) irradiating an optical material to be tested with ultraviolet radiation at a wavelength below 250 nm and determining non-intrinsic fluorescence intensity at a wavelength of 740 nm; b) irradiating the optical material to be tested with laser light and measuring a change in respective absorptions at a wavelength of 385 nm before and after irradiation; and c) irradiating the optical material to be tested with an energetic radiation source until saturation is achieved and measuring a difference of respective surface integrals of corresponding absorption spectra in ultraviolet spectral and/or visible spectral regions before and after irradiation with said energetic radiation source; wherein said energetic radiation source is an X-ray source or a radioactive source.