Winston cone

A Winston cone is a non-imaging light collector in the shape of an off-axis parabola of revolution{{cite web|url=http://www.ericweisstein.com/research/thesis/node21.html|title=Winston Cone|author=Eric W. Weisstein|year=1996}}{{cite web|url=https://indico.fnal.gov/getFile.py/access?contribId=66&sessionId=14&resId=0&materialId=slides&confId=5276|title=Winston Cones for a Cylindrical WCD|author=Stefano Perasso|date=2012-06-16}} with a reflective inner surface.

It concentrates the light passing through a relatively large entrance aperture through a smaller exit aperture. The collection of incoming rays is maximized by allowing off-axis rays to make multiple reflections before reaching the exit aperture. Winston cones are used to concentrate light from a large area onto a smaller photodetector or photomultiplier. They are widely used for measurements in the far infrared portion of the electromagnetic spectrum in part because there are no suitable materials to form lenses in the range.

Winston cones were invented by physicist Roland Winston.{{cite journal |title=Efficient Light Coupler for Threshold Čerenkov Counters |first1=H. |last1=Hinterberger |first2=R. |last2=Winston |work=Rev. Sci. Instrum. |volume=37 |pages=1094–1095 |year=1966 |doi=10.1063/1.1720428}}{{cite journal |title=Light Collection within the Framework of Geometrical Optics |first=Roland |last=Winston |work=J. Opt. Soc. Am. |volume=60 |issue=2 |pages=245-247 |year=1970 |doi=10.1364/JOSA.60.000245}}{{cite conference |first=Roland |last=Winston |title=How nonimaging optics began |publisher=SPIE, the International Society for Optics and Photonics |volume=9955 |conference=Nonimaging Optics: Efficient Design for Illumination and Solar Concentration XIII—Commemorating the 50th Anniversary of Nonimaging Optics |pages=995502 |date=8 September 2016 |editor-first1=Roland |editor-last1=Winston |editor-first2=Jeffrey M. |editor-last2=Gordon |doi=10.1117/12.2239175}}

It is commercialized by companies such as Winston Cone Optics{{Cite web|url=http://winstonconeoptics.com/|title=Welcome to Winston Cone Optics {{!}} Winston Cone Optics|website=winstonconeoptics.com|access-date=2019-03-13}}