Patent ID: 7787729
Filing Date: 2010-08-31
Classification: G02B,G02F,H01S

Abstract:
1. An optical fiber for propagating lower order modes, having order N or less and having a wavelength, λ,while limiting propagation of all higher order modes with order greater than N by providing said all higher order modes with a higher loss than said lower order modes at said wavelength, λ, said optical fiber comprising: a first cladding region comprising a plurality of lower-index cladding features, each of said plurality of lower-index cladding features having a refractive index lower than a refractive index of said first cladding region, said plurality of lower-index cladding features arranged in no more than two layers; and a core region surrounded by said first cladding region, said core region substantially surrounded by each layer of said no more than two layers, said plurality of lower-index cladding features configured to substantially confine propagation of said lower order modes to said core region, said core region having a width of at least about 20 micrometers, wherein said order N is less than or equal to 20, and wherein said core region is configured to provide a loss for said all higher order modes of at least about 0.5 dB.