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AssigneeThe United States of America as represented by the United States Department of Energy
InventorsMark A. Summers, Wilhelm F. Hagen, Robert D. Boyd
Estimating the term…
A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.
A harmonic conversion device for converting a single input laser beam at a fundamental frequency to a single output laser beam at a harmonic frequency, said device being for use in a large aperture laser system, said device being comprised of a plurality of crystals which are fitted together to form a single conversion device of diameter sufficient for use in a large aperture laser system, a grid of divider elements provided between said crystals, said grid elements constituting optical discontinuities that produce diffraction peaks as a single laser beam is passed through all of the crystals of the conversion device, said device further comprising:
Dependencies are inferred from the claim text.