18 research outputs found
Design and fabrication of an all-dielectric grating with top-hat high diffraction efficiency over a broad spectral range
Between 98% and 100% flat top efficiency –1st order TE diffraction over a 40 nm wavelength range centered at 800 nm can be obtained by an all-dielectric grating structure where the corrugation is etched in a high index layer unlike in the state of the art. 98% maximum efficiency and a wide-band top-hat diffraction efficiency spectrum are demonstrated experimentally opening to high efficiency femtosecond pulse compression for high average power laser machining
Diffraction from a stratified periodical medium by the true modal method
International audienc
Modal phenomenology of arbitrarily narrow reflection at high-contrast binary gratings
International audienc
Holistic fabrication of stitchingless subwavelength cylindrical gratings by phase-mask coordinate transform
International audienceA periodic grating with integer number of periods is fabricated at the resist-coated wall of a cylinder by exposing a circularly symmetrical planar high-index phase-mask to a cylindrical wave. This allows a transposition of the spatial coherence features easily achieved in a planar 2D space to the 3D space of cylindrical waves and elements
Subwavelength cylindrical grating by holistic phase-mask coordinate transform
International audienc
Resonant grating pulse compression element with 99% flat top efficiency for high average power femtosecond laser machining
International audienceTop hat diffraction efficiency in an all-dielectric SiO2/HfO2grating femtosecond pulse compression grating is demonstrated with a close to 100% flat top over more than 20 nm around 800 nm wavelength. New perspectives are open for high average power femtosecond laser machinin