Fresnel lens in the context of "Dioptrics"

Augustin-Jean Fresnel (10 May 1788 – 14 July 1827) was a French civil engineer and physicist whose research in optics led to the almost unanimous acceptance of the wave theory of light, fully supplanting Newton's corpuscular theory, from the late 1830s  until the end of the 19th century. He is perhaps better known for inventing the catadioptric (reflective/refractive) Fresnel lens and for pioneering the use of "stepped" lenses to extend the visibility of lighthouses, saving countless lives at sea. The simpler dioptric (purely refractive) stepped lens, first proposed by Count Buffon  and independently reinvented by Fresnel, is used in screen magnifiers and in condenser lenses for overhead projectors.

Fresnel gave the first satisfactory explanation of diffraction by straight edges, including the first satisfactory wave-based explanation of rectilinear propagation. By further supposing that light waves are purely transverse, Fresnel explained the nature of polarization. He then worked on double refraction.

A compact linear Fresnel reflector (CLFR) – also referred to as a concentrating linear Fresnel reflector – is a specific type of linear Fresnel reflector (LFR) technology. It is named for its similarity to a Fresnel lens, in which many small, thin lens fragments are combined to simulate a much thicker simple lens. These mirrors are capable of concentrating the sun's energy to approximately 30 times its normal intensity.

Linear Fresnel reflectors use long, thin segments of mirrors to focus sunlight onto a fixed absorber located at a common focal point of the reflectors. This concentrated energy is transferred through the absorber into some thermal fluid (this is typically oil capable of maintaining a liquid state at very high temperatures). The fluid then goes through a heat exchanger to power a steam generator. As opposed to traditional LFRs, the CLFR utilizes multiple absorbers within the vicinity of the mirrors.

Coast Guard Station Eatons Neck is a United States Coast Guard station located on the northern tip of Eatons Neck on Long Island, New York. It is the oldest Coast Guard Station in New York and the fourth oldest in the United States. It was founded in 1849 by the New York Lifesaving Benevolent Association.

The Eatons Neck Lighthouse is on the grounds of the station. Eatons Neck Lighthouse is the second oldest lighthouse on Long Island and the sixth oldest in the United States. First established in 1799, the present tower on a bluff stands 126 feet above sea level and shows a fixed white light from its Third Order Fresnel lens. The tower was placed on the National Register of Historic Places in 1973.