Aperture-Scalable High Performance Diffraction Gratings

b. Aperture-Scalable High Performance Diffraction Gratings Diffraction gratings are employed in high energy laser systems in several ways, including pump wavelength stabilization, spectral beam combining, pulse compression, and near-field spatial filtering. These components are of critical importance in enabling high average power petawatt-class laser systems. Traditional surface-etched gratings, while aperture scalable, suffer from poor diffraction efficiency and high loss. Volumetric gratings deliver high diffraction efficiencies with excellent spectral and angular selectivity but suffer from poor uniformity when scaling to large apertures needed in high energy laser systems. Grant proposals are sought which will enable scaling of dispersive optical elements to large apertures (greater than 10 cm x 10 cm) while maintaining excellent uniformity (5% minimum, with >10% preferred), high diffraction efficiency (>95% minimum at 1 micron or >90% minimum at 10 microns), and high optical damage threshold (>0.5 J/cm2 at 1 ps or >10 J/cm2 at 1 ns). Proposals that include work to develop new grating substrate technologies (e.g., ceramics with or without embedded cooling) that are capable of very high average power operation (>1 kW average) are encouraged. Of particular interest are technologies which enable such improvements while reducing the cost of such components. Questions Contact: Eric Colby, eric.colby@science.doe.gov