Fresnel lens

American  

noun

1. Optics. a large lens with a surface of concentric grooves of prismatic profile, used in automobile headlights, searchlights, spotlights, etc.

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Fresnel lens British  

noun

1. a lens consisting of a number of smaller lenses arranged to give a flat surface of short focal length

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Fresnel lens Scientific  

/ frə-nĕl′ /

1. A thin optical lens consisting of concentric rings of segmental lenses and having a short focal length. Placing a light source at the focal point of the lens gives rise to a strong beam of nearly parallel rays. Fresnel lenses are used primarily in spotlights, lighthouses, and the headlights of motor vehicles.

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Etymology

Origin of Fresnel lens

First recorded in 1840–50; fresnel

Example Sentences

This is called a 'Fresnel lens' or 'zone plate lens', and it focuses light using diffraction rather than refraction.

From Science Daily

Before the 11 a.m. boat ride back to the mainland, Dre Elmore likes to show off the retired Fresnel lens and the array of still-working machinery in the fog signal building.

From Los Angeles Times

Notable for the eponymous 1898 lighthouse — the tallest in Washington state — visitors can climb the 135 steps to the lantern room, where the original Fresnel lens still signals the Gray’s Harbor entrance.

From Seattle Times

The next morning, I went to the visitor station, in the recently refurbished fog signal building, to see the lighthouse’s original, first-order — as the biggest versions are called — Fresnel lens on display.

From New York Times

Plenty of interactive exhibits brings the voyage to life, including hands-on experimentation with a chronometer and Fresnel lens, outtakes from the duo’s journal, and short films.

From Seattle Times