Freeform GRIN Optics for Illumination Design

Background

Lens made from homogeneous materials and refractive optics have intrinsic limitations in their ability to manipulate optical fields. In some settings, these limitations have practical consequences. For example, the prescribed illumination pattern of laser headlights requires multiple bulky reflective elements. To achieve desired resolution in cell-phone cameras lens stacks with 7 up to seven lenses are required which limits the thickness of the camera portion of the cell phone. Large telescopic photographic lenses also include many heavy optical lenses.

Technology Overview

GRIN optics have opened new doors for optical manipulation not possible with traditional optics. Prescribed illumination patterns such as are used in automobile headlights can be achieved with a single transmissive optic using our technology. The number of lenses in imaging stacks such as for cell phones can be reduced by 50% with no reduction in image quality.

Prescribed illumination patterns can be achieved in a single optical element by exploiting flexibility in the material index of refraction. The number of lens elements in an optical lens stack can be reduced by incorporating a GRIN field correction element as the last element in an optical stack.

Benefits

Laser-based automobile headlights can be reduced to a single optic element in front of the source. Architectural lighting can be structured so that light isn’t sent in directions which are not useful (such as skyward), reducing lumen requirements in the source as well as light pollution.

The number of lenses in a cell phone optical stack can be reduced (with no reduction in resolution) to just a few in number by incorporating a 3D GRIN field correction element before the sensor. Telescopic photography lenses can be reduced in weight and complexity in the same manner.

 

URV Reference Number: 2-21004
Patent Information:
Category(s):
Optics
For Information, Contact:
Curtis Broadbent
Licensing Manager
University of Rochester
585.273.3250
curtis.broadbent@rochester.edu
Inventors:
Greg Schmidt
David Lippman
Keywords:
Optical Element