Abstract: A laser beam is generated and transmitted within an enclosed pathway through at least one crystal optic at a power density that progressively degrades transmissivity of the crystal optic with accumulating fluence. The crystal optics are cooled below normal operating temperatures to slow the progressive degradation in the transmissivity of the crystal optics with the accumulating fluence or to accommodate a higher power density without correspondingly increasing the progressive degradation in transmissivity.

Abstract: The invention is directed to large LCD image masks having a final flatness of less than 40 nm and a method of making such LCD image masks by utilizing subaperture deterministic grinding/lapping/polishing. In one preferred embodiment the final flatness is <20 ?m. In another the final flatness is <10 nm. The LCD image masks have a length and width that are each, independently of the other, greater than 400 mm and a thickness that is less than 20 mm. In at least one preferred embodiment the ICD image masks have a length and width that are each, independently, greater than 100 mm and the thickness is <15 mm. The glass LCD image masks can be of any glass materials suitable for LCD image masks. The method of the invention can be used with all such glasses. Exemplary LCD image mask glasses include fused silica, high purity fused silica and silica-titania containing 5-10 wt. % titania.

Abstract: A crystal optical material is illuminated at a wavelength of light that does not ionize the crystal optical material. Birefringence is measured between a plurality of voxels within the crystal optical material having spatial dimensions small enough to distinguish optical propagations of the light encountering boundary regions between subgrains of the crystal mosaic from optical propagations of the light through the subgrains themselves. The measured birefringence is evaluated for quantifying a characteristic of the crystal matrix. Metrics describing the crystal matrix are associated with performance of the crystal optical material.