Graded index structure for optical components with reduced polarization aberrations

Abstract

Methods, devices and systems are described that reduce polarization aberrations in waveguides used in a variety of applications, such as augmented or virtual reality. An example waveguide device includes a cladding with a first index of refraction, and a core with a plurality of layers that can maintain propagation of the polarized beam with multiple total internal reflections (TIRs). Each layer of the core has an index of refraction that is larger than the first index of refraction, and the core has a graded index profile that varies from a higher index at an inner core location to a lower index at an outer location of the core. The core has a predetermined number of layers such that a polarization retardance of the polarized beam for a range of angles of incidence spanning at least 6 degrees, and after a plurality of TIRs, remains less than 10 degrees.