An elongated LED lighting arrangement comprises an elongated light pipe with homogeneous optical material between first and second ends. In an exemplary embodiment, an LED provides blue light to the light pipe via a first dichroic mirror tuned to pass blue light. Down-converting means on sidewall of the light pipe, tuned to receive blue light, absorbs blue light from the LED and to emit lower-energy light outside of the light pipe at respectively higher wavelengths. Light-extracting means on the sidewall extract from the light pipe some blue light without changing the wavelengths of the foregoing light. Light from the down-converting means and the light-extracting means are combined to provide a composite color. The first dichroic mirror receives some light emitted by the down-converting means and reflects back into the light pipe more than 80 percent of the light received by the mirror.

Elongated LED lighting arrangement

A polarization based diagnostic device ( 200 ) for optically examining the medical condition of tissue ( 290 ) comprises an illumination optical system ( 205 ), comprising a light source ( 220 ) and beam shaping optics. An optical detection system ( 210 ) comprises imaging optics and an optical detector array, which detects light from the tissue. Polarizing optics provided in both the illumination optical system and the optical detection system are crossed and pass orthogonal polarization states. Iterative rotational means rotate the orthogonal polarization states relative to the tissue being examined. Image enhancement means includes image processing, sequential multi-spectral illumination and imaging, and image focus control to facilitate quality imaging at varying depths within the tissue. A controller ( 215 ) operates the light source, the detector array, the multi-spectral illumination and imaging, image focus control, and image processing.

Wound healing monitoring and treatment

An integrating rod ( 200 ) for use with a multiple segment dynamic filter, such as a spiral dichroic color wheel having three or more narrow filters adjacent to the exit face ( 206 ) to enable the integrating rod to recapture light rejected by a given segment of the dynamic filter. The rejected light travels back through the integrating rod where a majority of the light strikes the mirrored entrance face ( 202 ). Light reflected by the mirrored entrance face, or light exiting through the entrance aperture ( 204 ) and returning to the integrating rod after being reflected by the lamp reflector, once again travels to the exit face ( 206 ) of the integrating rod ( 200 ). After exiting through the exit face ( 206 ) of the integrating rod ( 200 ) a second time, the recycled light has a good chance of striking a different filter segment of the dynamic filter and being used by the display system.

Rod integrators for light recycling

In an illumination system the radiation from one or more laser arrays is directed into a light pipe. The light pipe mixes the individual radiation contributions from the laser arrays and forms a uniform illumination line. The pointing direction of each of the laser arrays is monitored and controlled to preserve the brightness of the composite illumination line.

Apparatus and method for illumination of light valves

A polarization based medical device for optically stimulating the formation of collagen in tissue comprises a light source for providing a beam of light. A polarizer polarizes the beam of light. A first beam shaping optics directs the polarized beam of light to a spatial light modulator. A second beam shaping optics directs the polarized beam from the spatial light modulator to an area of interest within the tissue. A spatially controlled pattern of polarized light is directed onto the tissue, thereby affecting the orientation of formation of collagen within the tissue.

Device for optically stimulating collagen formation in tissue

A recirculating light polarizer utilizes a reflective polarizer on the exit face of a light integrator, such as a light pipe or light tunnel. Light is provided to the light integrator and light of one polarization is transmitted through the polarizer, the remaining light being reflected back into the integrator. The back-reflected light accumulates polarization shift before it eventually is reflected back to the polarizer. The reflected light is further homogenized on its trip back to the polarizer. This process is typically repeated several times to enhance the light output from the light pipe assembly, with some light being lost in each cycle due to various loss mechanisms. A polarization state modifier, such as a retarder plate or phase-shifting coatings, may be included in the recirculating light path to enhance polarization shift.

Edward S. Sherman

Papers

Polarizing light pipe