Patent ID: 6191890
Filing Date: 2001-02-20
Classification: G02B,H01S

Abstract:
A system for transferring a beam of electromagnetic radiation having a vacuum wavelength, said system comprising:a first dielectric medium with a first refractive index n.sub.1 wherein said beam can propagate;a second dielectric medium with a second refractive index n.sub.2 ; anda dielectric region in between said first and said second medium, characterized in that said region has a periodicity of the dielectric properties parallel to said region, said periodicity having a period that is smaller than the wavelength of the electromagnetic radiation in said second dielectric medium, said dielectric properties and said periodicity of said dielectric region further being chosen such that the average refractive index of said dielectric region is not greater than said first refractive index n.sub.1 and not less than said second refractive index n.sub.2 and that the dielectric region establishes that said beam when incident on said dielectric region is reflected more than 90% into the specular zero-order reflection, said dielectric region further characterized in that said region has a sufficiently large variation of said dielectric properties within one repetition of said period such that said beam when incident on said dielectric region excites at least two modes propagating within said dielectric region along a direction normal thereto, and wherein at least one of the propagating modes is of higher order.