Over-wavelength pitch sized diffraction gratings for augmented reality applications
Valter Drazic, Oksana Shramkova, Bobin Varghese, Laurent Blondé, Vincent Brac De La Perrière, Jesse Schiffler, Patrice Twardowski, Sylvain Lecler, Benjamin Walter, Estelle Mairiaux, Fuanki Bavedila, Marc Faucher, Valérie Allié
Abstract
Waveguide based optical combiners for augmented reality (AR) glasses are integrating several surface relief gratings (SRG) whose pitch sizes can be as small as 200 nm for the blue wavelength. All SRG components exploit the first diffraction order to couple in and out or to deviate the light. We present SRG using higher diffraction orders featuring over-wavelength pitch sizes. Our gratings use the edge wave (EW) diffraction phenomenon to steer light in the preferred far field direction.
Topics & Concepts
DiffractionOpticsDiffraction efficiencyDiffraction gratingMaterials scienceOptoelectronicsAugmented realityNear and far fieldWaveguideHolographyField (mathematics)Physical opticsSurface (topology)Spatial frequencyLight fieldFresnel diffractionPtychographyTotal internal reflectionFabricationLight intensityEnhanced Data Rates for GSM EvolutionRefractive indexNear-field opticsHolographic displayPhysicsRigorous coupled-wave analysisAcousto-opticsIntegrated opticsGratingLight beamOptical Coatings and GratingsAdvanced Optical Imaging TechnologiesPhotorefractive and Nonlinear Optics