Angular filters for optical tomography of highly scattering media
OwnerGlenn Harrison Chapman, Bozena Kaminska +3inventors
InventorsGlenn Harrison Chapman, Bozena Kaminska, Paulman Konn Yan Chan, Fartash Vasefi, Nicholas Pfeiffer
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Abstract
An angular filter is provided, including a straight tunnel within a material, the tunnel having a roughened surface. When scattered light enters the tunnel, and strikes the roughened surface at a shallow angle, the scatter light is further scattered within the tunnel, striking the surface of the tunnel a multiplicity of times. Each such strike partially absorbs the light ray, such that the intensity of the scattered light exiting the tunnel is minimized.
Claims29
An angular filter, comprising:
- a straight tunnel within a material, said tunnel having an entrance, an exit and a surface;
- wherein at least a portion of said surface of said tunnel is roughened;
- and wherein when said entrance to said tunnel receives a plurality of light rays, said light rays including ballistic light rays and scattered light rays, said ballistic light rays pass through said tunnel to said exit, and a plurality of scattered light rays, strike said roughened surface, and scatter within said tunnel and are absorbed by said material.
An angular filter comprising a plurality of parallel tunnels within a material, each of said tunnels having an entrance, an exit and a surface, wherein at least a portion of said surface of each of said tunnels is roughened;
- and wherein when each of said entrances to said tunnels receives a plurality of light rays, said light rays including ballistic light rays and scattered light rays, said ballistic light rays pass through said tunnel to said exit, and a plurality of scattered light rays, strike said roughened surface of said tunnel, and scatter within said tunnel and are absorbed by said material.
A system for creating a two dimensional image of a scattering medium comprising:
- a. a light source on a first side of said scattering medium;
- b. an angular filter comprising a plurality of parallel tunnels within a material, each of said tunnels having an entrance, an exit and a surface, wherein at least a portion of said surface of each of said tunnels is roughened;
- and wherein when each of said entrances to said tunnels receives a plurality of light rays, said light rays including ballistic light rays and scattered light rays, said ballistic light rays pass through said tunnel to said exit, and a plurality of scattered light rays, strike said roughened surface of said tunnel, and are reflected within said tunnel and absorbed by said material;
- said entrances to said tunnels facing said scattering medium on an opposite side of said scattering medium;
- and
- c. an imaging pixel array detector facing said exits of said angular filter.
A method of filtering light comprising:
- (a) providing a plurality of light rays, including ballistic light rays and scattered light rays, to an entrance to a tunnel within a material, said tunnel having an exit and a surface, wherein at least a portion of said surface of said tunnel is roughened;
- (b) said ballistic light rays passing through said tunnel to said exit;
- and
- (c) a plurality of said scattered light rays, striking said roughened surface at a shallow angle, are scattered within said tunnel and absorbed by said material.
A method of roughening a surface of a tunnel, said surface made of silicon, by altering said surface to scatter light at shallow angles into a plurality of directions.
Dependencies are inferred from the claim text.