Selective collector for the wide-angle portion of a radiation beam

Claim 2

In combination with a radiation source emitting along an axis a relatively concentrated radiation component and a relatively diffuse radiation component, optical means for collecting radiation of the diffuse component while rejecting radiation of the concentrated component, comprising an optical light pipe mounted on the axis and having an end face directed toward the source for receiving radiation of both said components, an optical medium surrounding the light pipe sidewalls in optical contact therewith, and having an index of refraction greater than unity and less than the index of refraction of the light pipe, said indices of refraction being so selected that essentially all radiation of the concentrated component entering the light pipe is totally reflected at the light pipe sidewalls and that a major portion of the radiation of the diffuse component entering the light pipe is transmitted through the light pipe sidewalls into the medium as a generally coaxial annular radiation beam, and optical condensing means for collecting said annular radiation beam.

Claim 3

Optical means as defined in claim 1, and in which the index of refraction of said medium is at least about 0.95 times the index of refraction of the light pipe.

Claim 4

Optical means as defined in claim 1, and in which said medium comprises a transparent liquid contacting the sidewalls of the light pipe and enclosed within a generally coaxial chamber, said optical condensing means including an optical element forming an end wall of the chamber.

Claim 5

Optical means as defined in claim 1, and in which said radiation source comprises fluorescent material having a plane front surface perpendicular to said axis and capable of being energized by relatively concentrated radiation directed along the axis toward said surface, said relatively concentrated emitted radiation component comprising energizing radiation specularly reflected at said surface and said relatively diffuse emitted component comprising fluorescent emission from said material, said combination including means for directing radiation in a relatively concentrated beam toward the other end of said light pipe for transmission along the pipe by total reflection at its sidewalls to energize the radiation source.

Claim 6

In combination, a device for translating a relatively concentrated beam of incident raDiation into a relatively diffuse beam of processed radiation, said device including an aperture for receiving incident radiation and for delivering processed radiation, an optical light pipe having one end face optically directed toward the aperture for radiation interchange with the device, means for directing into the other end of the light pipe incident radiation in a concentrated beam, structure immersing the light pipe sidewalls in an optical medium having an index of refraction greater than unity and less than the index of refraction of the light pipe, said indices of refraction being such that substantially all incident radiation is retained within the light pipe by total reflection at the sidewalls for delivery to the device, and such that a major portion of the diffuse processed radiation delivered through said one end wall to the light pipe from the device is transmitted through the light pipe sidewalls into the medium as a generally coaxial annular radiation beam, and optical condensing means for collecting said annular radiation beam.

Claim 7

In combination, a device for translating a relatively concentrated beam of incident raDiation into a relatively diffuse beam of processed radiation, said device including an aperture for receiving incident radiation and for delivering processed radiation, an optical light pipe having one end face optically directed toward the aperture for radiation interchange with the device, means for directing into the other end of the light pipe incident radiation in a concentrated beam, structure immersing the light pipe sidewalls in an optical medium having an index of refraction greater than unity and less than the index of refraction of the light pipe, said indices of refraction being such that substantially all incident radiation is retained within the light pipe by total reflection at the sidewalls for delivery to the device, and such that a major portion of the diffuse processed radiation delivered through said one end wall to the light pipe from the device is transmitted through the light pipe sidewalls into the medium as a generally coaxial annular radiation beam, and optical condensing means for collecting said annular radiation beam.

Claim 8

The combination defined in claim 5, and in which said radiation-translating device comprises a resonance backscatter cell having a window at said aperture.

Claim 9

The combination defined in claim 6, and in which said window is of such form that substantially all incident radiation that is specularly reflected by the window back into the light pipe is retained therein by total reflection at the sidewalls.

Claim 10

The combination defined in claim 5, and in which the index of refraction of said medium is at least about 0.95 times the index of refraction of the light pipe.