Light-diffusing optical elements having cladding with scattering centers
AssigneeCorning Incorporated
InventorStephan Lvovich Logunov
Life of this patent
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Abstract
A light-diffusing optical element with efficient coupling to light sources with high numerical aperture. The light-diffusing optical element includes a higher index core surrounded by a lower index cladding. The cladding includes scattering centers that scatter evanescent light entering the cladding from the core. The scattered light exits the element to provide broad-area illumination along the element. Scattering centers include dopants, nanoparticles and/or internal voids. The core may also include scattering centers. The core is glass and the cladding may be glass or a polymer. The element features high numerical aperture and high scattering efficiency.
Claims30
A light-diffusing element comprising:
- a glass core, said glass core having a diameter greater than 65 μm;
- and
- a cladding surrounding said glass core, said cladding having a lower refractive index than said glass core, said cladding including first scattering centers, said first scattering centers having a cross-section with a dimension of at least 25 nm;
- wherein said element exhibits light scattering losses of at least 0.1 dB/m.
An illumination system comprising:
- a light source optically coupled to a light-diffusing element, said light-diffusing element comprising:
- a glass core, said glass core having a diameter greater than 65 μm;
- and
- a cladding surrounding said glass core, said cladding having a lower refractive index than said glass core, said cladding including first scattering centers, said first scattering centers having a cross-section with a dimension of at least 25 nm;
- wherein said element exhibits light scattering losses of at least 0.1 dB/m.
A method for forming a light-diffusing element comprising:
- forming a core, said core comprising glass;
- forming a cladding in direct contact with said core, said cladding including first scattering centers, said first scattering centers having a cross-section with a dimension of at least 25 nm.
A method for forming a light-diffusing element comprising:
- forming a core, said core comprising glass, said forming core including drawing a glass preform;
- forming a cladding on said core, said cladding including first scattering centers, said first scattering centers having a cross-section with a dimension of at least 25 nm, said forming cladding including applying a curable composition to said core and curing said curable composition in the presence of a void-producing gas.
Dependencies are inferred from the claim text.