Plane of polarization: Difference between revisions

Revision as of 22:35, 29 August 2017

Revision as of 03:06, 1 September 2017

Line 4:

 

'''This page is underUNDER constructionCONSTRUCTION. Beware of loose bricks.'''

 

Line 32:

| [[Birefringence]]

| [[Diffraction]]

| [[Fresnel–Arago laws]]

| [[Fresnel equations]]

| [[Fresnel integral]]s

| [[Fresnel lens]]

| [[Fresnel number]]

Line 49 ⟶ 50:

}}

'''Augustin-Jean Fresnel''' ({{IPAc-en|f|r|eɪ|ˈ|n|ɛ|l}} {{respell|fray|NEL|'}}; {{IPA-fr|ɔ.ɡy.stɛ̃ ʒɑ̃ fʁɛ.nɛl|lang}}; 10 May 1788 – 14 July 1827) was a [[France|French]] civil [[engineer]] and [[physicist]] whose research in [[optics]] led to the almost universal acceptance of the wave theory of light, and the rejection of any remnant of [[Isaac Newton|Newton]]'s [[corpuscular theory of light|corpuscular theory]], from the 1830s{{r|darrigol-<ref>Darrigol, 2012|p=, pp.&nbsp;220–23}}</ref> until the end of the 19th century.

But 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 [[lighthouse|lighthouses]], saving unknown numbers of lives at sea. The simpler ''dioptric'' (purely refractive) stepped lens, first proposed by [[Georges-Louis Leclerc, Comte de Buffon|Count Buffon]]{{r|chisholm-1911-lighthouse}} and independently reinvented by Fresnel, is used in screen [[magnifying glass|magnifiers]] and in condenser lenses for [[overhead projector|overhead projectors]].

By expressing [[Christiaan Huygens|Huygens]]' principle of secondary waves and [[Thomas Young (scientist)|Young]]'s principle of [[interference (wave propagation)|interference]] in quantitative terms, and supposing that simple colors consist of ''[[sine wave|sinusoidal]]'' waves, Fresnel gave the first satisfactory explanation of [[diffraction]] by straight edges, including the first explanation of rectilinear propagation that would satisfy a modern physicist.{{r|darrigol-<ref>Darrigol, 2012|, p=.205}}</ref> By further supposing that light waves are purely ''[[transverse wave|transverse]]'', he explained the nature of [[polarization]] and lack thereof, the mechanism of ''chromatic polarization'' (the colors produced when polarized light is passed through a slice of doubly-refractive crystal followed by a second polarizer), and the [[transmission coefficient|transmission]] and [[reflection coefficient]]s at a boundary between transparent [[isotropy|isotropic]] media (including [[Brewster's angle]]). Then, by generalizing the relationship between wave speed and polarization for [[calcite]], he accounted for the directions and polarizations of the refracted rays in [[birefringence|doubly-refractive]] crystals of the ''biaxial'' class (those for which Huygens' secondary wavefronts are not axisymmetric). The period between the first publication of his pure-transverse-wave hypothesis and the presentation of his solution to the biaxial problem was less than a year. Later, by allowing the reflection coefficient to be ''[[complex number|complex]]'', he accounted for the change in polarization due to [[total internal reflection]], as exploited in the [[Fresnel rhomb]]. Defenders of the established corpuscular theory could not match his quantitative explanations of so many phenomena on so few assumptions.

Fresnel's legacy is the more remarkable in view of his lifelong battle with [[tuberculosis]], to which he succumbed at the age of 39. Although he did not become a public celebrity in his short lifetime, he lived just long enough to receive due recognition from his peers, including (on his deathbed) the [[Rumford Medal]] of the [[Royal Society of London]], and his name recurs frequently in the modern terminology of optics and waves.

Line 62 ⟶ 63:

=== Family ===

Augustin-Jean Fresnel (also called Augustin Jean or simply Augustin), born in [[Broglie, Eure|Broglie]], [[Normandy]], on 10&nbsp;May 1788, was the second of four sons of the architect Jacques Fresnel (1755–1805){{r|favre}} and his wife Augustine, ''née'' Mérimée (1755?–1833).{{r|jeanelie}} In 1790, following the [[French Revolution|Revolution]], Broglie became part of the [[Departments of France|département]] of [[Eure]]. The family moved twice — in 1790 to [[Cherbourg-Octeville|Cherbourg]],<ref>Levitt, 2013, p.23.</ref> and in 1794{{r|silliman-2008|p=166}} to Jacques' home town of [[Mathieu, Calvados|Mathieu]], where Madame Fresnel remained as a widow,{{r|boutry|p=590}} outliving two of her sons.

The first son, Louis (1786–1809), was admitted to the [[École Polytechnique]], became a lieutenant in the artillery, and was killed at [[Jaca]], [[Spain]], the day before his 23rd birthday.{{r|jeanelie}} The third, Léonor (1790–1869),{{r|favre}} followed Augustin into civil [[engineer]]ing, succeeded him as Secretary of the Lighthouse Commission,<ref>Levitt, 2013, p.99.</ref> and helped to edit his collected works (Fresnel, ''Oeuvres complètes'', 1866–70). The fourth, [[Fulgence Fresnel]] (1795–1855), became a noted linguist, diplomat, and orientalist, and occasionally assisted Augustin with negotiations.<ref>Levitt, 2013, p.72.</ref>

Their mother's brother Léonor Mérimée (1757–1836),{{r|jeanelie}} father of the writer [[Prosper Mérimée]] (1803–1870), was a painter who studied the chemistry of painting. He became the Permanent Secretary of the [[École des Beaux-Arts]] (School of Fine Arts) and a professor at the École polytechnique, and was the initial point of contact between Augustin and the French scientific establishment (see below).

=== Education ===

Augustin and his brothers were initially home-schooled by their

mother. Augustin was considered the slow one, not beginning to read

until the age of eight. At ten he was undistinguished except for his

ability to turn tree-branches into toy bows and cannon that were too

dangerous to play with, provoking a crackdown from his elders.

e have a tradition that, at the age of eight

could not read well and had difficulty in remembering new words.

There was no laziness there : all his life, Fresnel was to loath

the simplest exercises of memory

591: It seems he

went on experimenting in ballistics till his weapons became so

effective that a deputation of frenzied farmers had to wait upon the

schoolmaster ; the supposedly slow-witted boy was then aged ten.

In October 1803, Louis is

examined in the annual competition for entry into the École Poly-

technique and accepted : we shall not hear again of poor Louis,

who perishes at twenty-two under Badajoz. In 1804, Augustin in

his turn is accepted. In some subjects he has barely passed, but

in Geometry his answers have surprised and delighted the examiner,

already a well-known man : Legendre.

592: Since the École's records, still preserved, begin in 1808, we know

next to nothing of Fresnel's life there. Health didn't improve

though it does not appear he ever had to stop attending.

seems to have excelled in the graphic arts and geometry. few or no friends.

His early progress in learning was slow, and when eight years old he was still unable to read. At the age of thirteen he entered the École Centrale in Caen, and at sixteen and a half the École Polytechnique, where he acquitted himself with distinction. Thence he went to the École des Ponts et Chaussées. He served as an engineer successively in the departments of Vendée, Drôme and Ille-et-Vilaine; but his espousal of the cause of the Bourbons in 1814 occasioned, on Napoleon’s reaccession to power, the loss of his appointment. On the second restoration he obtained a post as engineer in Paris.{{r|chisholm-1911-fresnel}}

Line 76 ⟶ 112:

Fresnel's parents were [[Catholic Church|Roman Catholics]] of the [[Jansenism|Jansenist]] sect, characterized by an extreme [[Augustine of Hippo|Augustinian]] view of [[original sin]]. In the early home-schooling that the four boys received from their mother, religion took first place. In 1802, Mme&nbsp;Fresnel wrote to Louis concerning Augustin:

{{quote|I pray God to give my son the grace to employ the great talents, which he has received, for his own benefit, and for the God of all. Much will be asked from him to whom much has been given, and most will be required of him who has received most.{{r|kneller-1911|p=147}} }}

Augustin Fresnel indeed regarded his intellectual talents as a gift from God, and considered it his duty to use them for the benefit of others. Plagued by poor health, and determined to do his duty before death thwarted him, he shunned pleasures and worked himself to exhaustion.{{r|silliman-2008|p=166}} According to his fellow engineer Alphonse Duleau, who helped to nurse him through his final illness, Fresnel saw the study of nature as the study of the power and goodness of God. He placed virtue above science and genius. Yet in his last days he needed "strength of soul"," not against death alone, but against "the interruption of discoveries… of which he hoped to derive useful applications."{{r|kneller-1911|p=148–9n}} Although Jansenism is considered [[heresy|heretical]] by the Roman Catholic Church, the brief article on Fresnel in the ''[[Catholic Encyclopedia]]'' (v.6, 1909) does not mention his Jansenism, but simplydescribes acknowledgeshim hisas deep"a religiositydeeply religious man and "remarkable" for his keen sense of duty."{{r|brock-1909}}

== Engineering assignments ==

Line 160 ⟶ 196:

=== Prior art ===

Fresnel was not the first person to focus a lighthouse beam using a lens. That distinction apparently belongs to the London glasscutter Thomas Rogers, who proposed the idea to [[Trinity House]] in 1788.{{r|tag-2017aprior}} The first Rogers lenses, 53cm in diameter and 14cm thick at the center, were installed at the [[Old Lower Lighthouse]] at [[Portland Bill]] in 1789.{{r|levitt-<ref>Levitt, 2013|, p=.57}}.</ref> Further samples followed at [[Baily Lighthouse|Howth Baily]], [[North Foreland]], and at least four other locations.{{r|tag-2017aprior}} But much of the light was wasted by absorption in the glass.

[[File:Fresnel lens.svg|thumb|upright|1: Cross-section of Buffon/Fresnel lens. 2:&nbsp;Cross-section of conventional [[Lens (optics)#Types of simple lenses|plano-convex lens]] of equivalent power. (Buffon's version was [[Lens (optics)#Types of simple lenses|biconvex]].{{r|levitt-<ref>Levitt, 2013|, p=.59}}.</ref>)]]

Nor was Fresnel the first to suggest replacing a convex lens with a series of concentric annular prisms, to reduce weight and absorption. In 1748, [[Georges-Louis Leclerc, Comte de Buffon|Count Buffon]] proposed grinding such prisms as steps in a single piece of glass.{{r|chisholm-1911-lighthouse}} In 1790{{r|condorcet-1790}} (although secondary sources give the date as 1773{{r|appleton-1861|p=609}} or 1788{{r|tag-2017}}), the [[Marquis de Condorcet]] suggested that it would be easier to make the annular sections separately and assemble them on a frame; but even that was impractical at the time.{{r|tag-2017bfres}}{{r|levitt-<ref>Levitt, 2013|, p=.71}}.</ref> These designs were intended not for lighthouses,{{r|chisholm-1911-lighthouse}} but for [[burning glass|burning glasses]].{{r|appleton-1861|p=609}} Brewster, however, proposed a system similar to Condorcet's in 1811,{{r|chisholm-1911-lighthouse|ripley-dana-1879|tag-2017}} and by 1820 was advocating its use in British lighthouses.{{r|chisholm-1911-brewster}}

=== Prototypes ===

Meanwhile, in June 1819, Fresnel was engaged by the ''Commission des phares'' (Commission of Lighthouses) on the recommendation of Arago (a member of the Commission since 1813), to review possible improvements in lighthouse illumination.{{r|tag-2017bfres}} The Commission had been established by Napoleon in 1811, and placed under the ''Corps des ponts'' — Fresnel's employer.{{r|levitt-<ref>Levitt, 2013|p=, pp.&nbsp;49–50}}.</ref>

On 29&nbsp;August 1819, unaware of the Buffon-Condorcet-Brewster proposal,{{r|ripley-dana-1879|tag-2017bfres}} Fresnel presented his first report, in which he recommended what he called ''lentilles à échelons'' (lenses by steps) to replace the reflectors then in use, which reflected only about half of the incident light.{{r|levitt-<ref>Levitt, 2013|p=, pp.&nbsp;56,58}}.</ref> One of the assembled commissioners, [[Jacques Charles]], recalled Buffon's suggestion. Fresnel was disappointed to discover that he had again "broken through an open door".{{r|levitt-<ref>Levitt, 2013|, p=.59}}.</ref> But, whereas Buffon's version was [[Lens (optics)#Types of simple lenses|biconvex]] and in one piece, Fresnel's was [[Lens (optics)#Types of simple lenses|plano-convex]] and made of multiple prisms for easier construction. With an official budget of 500 francs, Fresnel approached three manufacturers. The third, François Soleil, found a way to remove defects by reheating and remolding the glass. Arago assisted Fresnel with the design of a modified [[Argand lamp]] with concentric wicks (a concept that Fresnel attributed to [[Benjamin Thompson|Count Rumford]]{{r|fresnel-1822-phares|p=11}}), and accidentally discovered that fish glue was heat-resistant, making it suitable for use in the lens. The prototype, with a lens panel 55cm square, containing 97 polygonal (not annular) prisms, was finished in March 1820 — and so impressed the Commission that Fresnel was asked for a full eight-panel version. Completed a year later, largely at Fresnel's personal expense, this model had panels 72cm square. In a public spectacle on the evening of 13&nbsp;April 1821, it was demonstrated by comparison with the most recent reflectors, which it suddenly rendered obsolete.{{r|levitt-<ref>Levitt, 2013|p=, pp.&nbsp;59–66}}.</ref>

(Fresnel acknowledged the British lenses and Buffon's invention in a memoir published in 1822.{{r|fresnel-1822-phares|p=2–4}}. The date of that memoir may be the source of the claim that Fresnel's lighthouse advocacy began two years later than Brewster's;{{r|chisholm-1911-brewster}} but the text makes it clear that Fresnel's involvement began no later than 1819.{{r|fresnel-1822-phares|p=1}})

Line 178 ⟶ 214:

=== Fresnel's innovations ===

Fresnel's next lens, was a rotating apparatus with eight "bull's-eye" panels made in annular arcs by [[Saint-Gobain]],{{r|levitt-<ref>Levitt, 2013|, p=.71}} was a rotating apparatus with eight "bull's-eye" panels.</ref>, giving eight rotating beams, to be seen by mariners as a periodic flash. Above and behind each main panel was a smaller, sloping bull's-eye panel of trapezoidal outline, refractingwith trapezoidal elements.{{r|gombert-2017}} This refracted the light to a sloping plane mirror, which then reflected it horizontally, 7&nbsp;degrees ahead of the main beam, increasing the duration of the flash.{{r|fresnel-1822-phares|p=13,25}} Below the main panels were 128 small mirrors arranged in four rings, stacked like the slats of a [[louver]] or [[Venetian blind]]. Each ring, shaped like a [[frustum]] of a [[cone]], reflected the light to the horizon, giving a fainter steady light between the flashes. The official test, conducted on the ''[[Arc de Triomphe]]'' on 20&nbsp;August 1822, was witnessed by the Commission — and by [[Louis XVIII of France|Louis XVIII]] and his entourage — from 32km away. The apparatus was stored at [[Bordeaux]] for the winter, and then installedreassembled at [[Cordouan Lighthouse]] under Fresnel's supervision. On 25&nbsp;July 1823, the world's first lighthouse Fresnel lens was lit.{{r|levitt-<ref>Levitt, 2013|p=, pp.&nbsp;72–3}}.</ref> It was about this time that Fresnel started coughing up blood.{{r|levitt-<ref>Levitt, 2013|, p=.97;}}{{r|watson-2016|p=146}}

In 1824, Fresnel designed the first ''fixed'' lens — for spreading light evenly around the horizon{{r|tag-2017bfres}} while minimizing waste above or below. This had the familiar reflecting (''catoptric'') rings above and below the refracting (''dioptric'') panels. But the curved refracting surfaces were segments of toroids about a common vertical axis, so that the dioptric panel looked like a cylindrical drum and the entire apparatus looked like a beehive.

In May of the same year,{{r|ripley-dana-1879}} Fresnel was promoted to Secretary of the ''Commission des phares'', becoming the first member of that body to draw a salary.{{r|levitt-<ref>Levitt, 2013|, p=.82}}.</ref> He was also an examiner at the École Polytechnique (since 1821),{{r|brock-1909}} but poor health soon induced him to resign that post and save his energy for his lighthouse work.{{r|levitt-<ref>Levitt, 2013|, p=.97}}.</ref> The following year he unveiled the ''Carte des phares'' (Lighthouse Map), calling for a system of 51 lighthouses plus smaller harbor lights, in a hierarchy of lens sizes (called ''orders'', the first order being the largest), with different characteristics to facilitate recognition: a constant light (from a fixed lens), one flash per minute (from a rotating lens with eight panels), and two per minute (sixteen panels). On 1&nbsp;February 1825, the second lighthouse Fresnel lens entered service: a third-order fixed lens at Dunkirk.{{r|levitt-<ref>Levitt, 2013|p=, pp.&nbsp;83–4}}.</ref>

Also in 1825, Fresnel extended his fixed design by adding a rotating array outside the fixed array.{{r|tag-2017bfres}} Each panel of the rotating array refracted part of the fixed light from a horizontal fan into a narrow beam.

[[File:MuseeMarine-phareFresnel-p1000466.jpg|thumb|left|First-order rotating catadioptric Fresnel lens, made indated 1870, on display at the ''[[Musée national de la Marine]]'', Paris. In this case the dioptric prisms (inside the bronze circles) and catadioptric prisms (outside) are arranged to give a purely flashing light with four flashes per rotation. The assembly stands 2.54 metres tall and weighs about 1.5 tonnes.]]

To reduce the loss of light in the reflecting elements, Fresnel proposed to replace the mirrors with ''catadioptric'' prisms, through which the light would pass by two refractions and one [[total internal reflection]].{{r|levitt-<ref>Levitt, 2013|p=, pp.&nbsp;79–80}}.</ref> The result was the lighthouse lens as we now know it. In 1826 he assembled a small model for use on the [[Canal Saint-Martin]],{{r|musee-2017}} but he did not live to see a full-sized version.

The first large catadioptric lenses were made in 1842 for the lighthouses at Gravelines and [[Île Vierge]]; these were fixed third-order lenses whose catadoptric rings (made in segments) were one metre in diameter.{{r|levitt-2013|p=109}} The first-order [[Skerryvore]] lens, installed in 1844, was only partly catadoptric; it was similar to the Cordouan lens except that the lower slats were replaced by French-made catadioptric prisms, while mirrors were retained at the top.{{r|levitt-2013|p=108–10}} The first ''fully'' catadioptric first-order lens, installed at Ailly in 1852, also gave eight rotating beams plus a fixed light at the bottom; but its top section had eight catadioptric panels focusing the light about 4 degrees ahead of the main beams, in order to lengthen the flashes. The first fully catadioptric lens with ''purely revolving'' beams — also of first order — was installed at [[Saint-Clément-des-Baleines]] in 1854, and marked the completion of Fresnel's original ''Carte des phares''.{{r|levitt-<ref>Levitt, 2013|p=, pp.&nbsp;108–10, 113–16}}.</ref>

[[File:Flat flexible plastic sheet lens.JPG|thumb|Close-up view of a thin plastic Fresnel lens.]]

Line 197 ⟶ 233:

Production of one-piece stepped lenses (roughly as envisaged by Buffon) eventually became profitable. By the 1870s, in the USA, such lenses were made of pressed glass and used with small lights on ships and piers.{{r|ripley-dana-1879}} Similar lenses, with finer steps, serve as condensers in [[overhead projector|overhead projectors]]. Still finer steps can be found in low-cost plastic "sheet" [[magnifying glass|magnifiers]].

{{clear}}

== Honors ==

Line 212 ⟶ 250:

In 1827 he received the [[Rumford Medal]].{{r|rines-1919|chisholm-1911-fresnel}}

In 1824,{{r|levitt-<ref>Levitt, 2013}}, p.77.</ref> he was made a ''chevalier de la Légion d'honneur'' (Knight of the [[Legion of Honour]]).{{r|academie-2017}}

== Decline and death ==

[[File:Tombe d'Augustin Fresnel - Père Lachaise.JPG|thumb|Fresnel's grave at [[Père Lachaise Cemetery]], Paris, photographed in 2014. The inscription on the headstone is partly [https://[commons.wikimedia.org/wiki/Category:Grave_of_Augustin_Fresnel_category:Grave of Augustin Fresnel (P%C3%A8rePère-Lachaise,_division_14) division 14)|eroded away.] ].]]

Rumford medal, which was

presented to him upon his deathbed by his friend

and collaborator Arago.{{r|ripley-dana-1879}}

{{clear}}

== Unfinished business ==

Line 230 ⟶ 270:

== Legacy ==

[[File:Cordouan6.jpg|thumb|The lantern room of the [[Cordouan Lighthouse]], in which the first Fresnel lens entered service in 1823. The current fixed catadioptric "beehive" lens replaced Fresnel's original rotating lens in 1854.{{r|phare-2017pharedeC}}]]

With a century after Fresnel's initial proposal, more than 10,000 lights with Fresnel lenses marked coastlines around the world.{{r|levitt-<ref>Levitt, 2013|, p.19}}.</ref> The numbers of lives saved can only be guessed at. Concerning the other benefits, science historian Theresa H. Levitt has remarked:

{{quote|Everywhere I looked, the story repeated itself. The moment a Fresnel lens appeared at a ___location was the moment that region becamed linked into the world economy.{{r|levitt-<ref>Levitt, 2013|8}}, p.8.</ref>}}

In the history of physical optics, Fresnel's successful revival of the wave theory seems to identify him as the pivotal figure between Newton, who held that light consisted of corpuscles, and [[James Clerk Maxwell|Maxwell]], who established that light waves are electromagnetic. Whereas [[Albert Einstein|Einstein]] described Maxwell's work as "the most profound and the most fruitful that physics has experienced since the time of Newton,"{{r|jamesCMF}} commentators of the era between Fresnel and Maxwell made similarly strong statements about Fresnel:

Line 249 ⟶ 289:

Although Fresnel did not know that light waves are electromagnetic, he managed to construct the world's first coherent theory of light. In retrospect, this shows that his methods are applicable to multiple types of waves. And although light is now known to have both wavelike and particle-like aspects, it is the wavelike aspect that more easily explains the phenomena studied by Fresnel. In these respects, Fresnel's theory has stood the test of time, and Whewell's premature triumphalism contains an abiding truth.

{{clear}}

== References ==

Line 254 ⟶ 296:

{{Reflist|30em|refs=

<ref name=academie-2017>Académie des sciences, ''Membres…'' [http://www.academie-sciences.fr/pdf/dossiers/Fresnel/Fresnel_oeuvre.htm "Augustin Fresnel"], accessed 21&nbsp;August 2017; [https://web.archive.org/web/20170215201835/http://www.academie-sciences.fr/pdf/dossiers/Fresnel/Fresnel_oeuvre.htm archived] 15&nbsp;February 2017.</ref>

<ref name=appleton-1861>D. Appleton &amp; Co., "Sea-lights", ''Dictionary of Machines, Mechanics, Engine-work, and Engineering'', 1861, [https://archive.org/details/appletonsdiction02appl v.2].</ref>

Line 270 ⟶ 312:

<ref name=condorcet-1790>Nicolas de Condorcet, [https://books.google.com.au/books?id=o99ZAAAAcAAJ ''Éloge de M.&nbsp;le Comte de Buffon''], Paris: Chez Buisson, 1790, pp.&nbsp;11–12.</ref>

<ref name=favre>J.H. Favre, "Augustin Fresnel", gw.geneanet.org, accessed 30&nbsp;August 2017.</ref>

<ref name=crew-1900>H. Crew (ed.), [https://archive.org/details/wavetheoryofligh00crewrich ''The Wave Theory of Light: Memoirs by Huygens, Young and Fresnel''], American Book Co., 1900.</ref>

<ref name=fresnel-1819b>A. Fresnel, "Mémoire sur la diffraction de la lumière" (deposited 1818, "crowned" 1819), in ''Oeuvres complètes'', [https://books.google.com/books?id=1l0_AAAAcAAJ v.1], pp.&nbsp;247&ndash;364; partly translated as "Fresnel's prize memoir on the diffraction of light", in H.&nbsp;Crew&nbsp;(ed.), [https://archive.org/details/wavetheoryofligh00crewrich ''The Wave Theory of Light: Memoirs by HuygensCrew, Young and Fresnel''1900], American Book Co., 1900, pp.&nbsp;81&ndash;144. (Not to be confused with the earlier memoir of the same title in ''Annales de Chimie et de Physique'', 1:239&ndash;81, 1816.)</ref>

<ref name=darrigol-2012>O. Darrigol, ''A History of Optics: From Greek antiquity to the nineteenth century'', Oxford, 2012.</ref>

<ref name=fresnel-1819b>A. Fresnel, "Mémoire sur la diffraction de la lumière" (deposited 1818, "crowned" 1819), in ''Oeuvres complètes'', [https://books.google.com/books?id=1l0_AAAAcAAJ v.1], pp.&nbsp;247&ndash;364; partly translated as "Fresnel's prize memoir on the diffraction of light", in H.&nbsp;Crew&nbsp;(ed.), [https://archive.org/details/wavetheoryofligh00crewrich ''The Wave Theory of Light: Memoirs by Huygens, Young and Fresnel''], American Book Co., 1900, pp.&nbsp;81&ndash;144. (Not to be confused with the earlier memoir of the same title in ''Annales de Chimie et de Physique'', 1:239&ndash;81, 1816.)</ref>

<ref name=fresnel-1822-phares>A. Fresnel, "Mémoire sur un nouveau système d'éclairage des phares", read at the Académie des Sciences, 29&nbsp;July 1822; translated by T.&nbsp;Tag as [http://uslhs.org/sites/default/files/attached-files/Fresnel%27s%20Memoire%20-%20Translation.pdf "Memoir Upon A New System Of Lighthouse Illumination"], U.S. Lighthouse Society, accessed 26&nbsp;August 2017; [https://web.archive.org/web/20160819111647/http://uslhs.org/sites/default/files/attached-files/Fresnel's%20Memoire%20-%20Translation.pdf archived] 19&nbsp;August 2016.</ref>

<ref name=gombert-2017>D. Gombert, [https://www.flickr.com/photos/gebete29/32970312394/in/photostream/ photograph of the ''Optique de Cordouan''] in the [http://www.pnr-armorique.fr/Visiter/Musees-maisons-a-themes/Musee-des-Phares-et-Balises/collection-du-musee collection of the ''Musée des Phares et Balises''], [[Ushant|Ouessant]], France, 23&nbsp;March 2017.</ref>

<ref name=fresnel-oc>A. Fresnel (ed. H. de Senarmont, E.&nbsp;Verdet, L.&nbsp;Frenel), ''Oeuvres complètes d'Augustin Fresnel'' (3 vols.), Paris: Imprimerie impériale, 1866&ndash;70; [https://books.google.com/books?id=1l0_AAAAcAAJ v.1&nbsp;(1866)], [https://archive.org/details/oeuvrescompltes00fresgoog v.2&nbsp;(1868)], [https://archive.org/details/oeuvrescompltes01fresgoog v.3&nbsp;(1870)].</ref>

<ref name=jamesCMF>James Clerk Maxwell Foundation, [http://www.clerkmaxwellfoundation.org/html/about_maxwell.html "Who was James Clerk Maxwell?"], accessed 6&nbsp;August 2017; [https://web.archive.org/web/20170630003106/http://www.clerkmaxwellfoundation.org/html/about_maxwell.html archived] 30&nbsp;June 2017.</ref>

<ref name=jeanelie>'jeanelie' (author), "Augustine Charlotte Marie Louise Merimee" and "Louis Jacques Fresnel", gw.geneanet.org, accessed 30&nbsp;August 2017.</ref>

<ref name=kneller-1911>K.A. Kneller (tr. T.M. Kettle), [https://archive.org/details/christianitylead00knelrich ''Christianity and the Leaders of Modern Science: A contribution to the history of culture in the nineteenth century''], Freiburg im Breisgau: B.&nbsp;Herder, 1911, pp.&nbsp;147–9.</ref>

<ref name=levitt-2013>T.H. Levitt, ''A Short Bright Flash: Augustin Fresnel and the Birth of the Modern Lighthouse'', New York: W.W.&nbsp;Norton, 2013.</ref>

<ref name=lloyd-1834>H. Lloyd, "Report on the progress and present state of physical optics", [https://books.google.com/books?id=mtU4AAAAMAAJ ''Report of the Fourth Meeting of the British Association for the Advancement of Science''] (held at Edinburgh in 1834), London: J.&nbsp;Murray, 1835, pp.&nbsp;295–413.</ref>

Line 294 ⟶ 334:

<ref name=macCullagh-1830>J. MacCullagh, "On the Double Refraction of Light in a Crystallized Medium, according to the Principles of Fresnel", ''Transactions of the Royal Irish Academy'', v.16&nbsp;(1830), pp.&nbsp;65–78; [http://www.jstor.org/stable/30079025 jstor.org/stable/30079025].</ref>

<ref name=musee-2017>Musée national de la Marine, [http://mnm.webmuseo.com/ws/musee-national-marine/app/collection/record/9067 "Appareil catadioptrique, Appareil du canal Saint-Martin"], accessed 26&nbsp;August 2017; [https://web.archive.org/web/20170826030358/http://mnm.webmuseo.com/ws/musee-national-marine/app/collection/record/9067 archived] 26&nbsp;August 2017.</ref>

<ref name=phare-2017pharedeC>Phare de Cordouan, [http://www.phare-de-cordouan.fr/lighting-systems.html "The lighting systems of the Cordouan Lighthouse"], accessed 26&nbsp;August 2017; [https://web.archive.org/web/20160922153001/http://www.phare-de-cordouan.fr/lighting-systems.html archived] 22&nbsp;September 2016.</ref>

<ref name=rines-1919>G.E. Rines (ed.), "Fresnel, Augustin Jean", ''Encyclopedia Americana'', 1918–20, v.12 (1919), [https://babel.hathitrust.org/cgi/pt?id=wu.89094370657;view=1up;seq=111 p.93]. (''Note:'' This entry inaccurately describes Fresnel as the "discoverer" of polarization of light and as a "Fellow" of the Royal Society, whereas in fact he ''explained'' polarization and was a "Foreign Member" of the Society.)</ref>

Line 306 ⟶ 346:

<ref name=tag-2017>T. Tag, [http://uslhs.org/chronology-lighthouse-events "Chronology of Lighthouse Events"], U.S. Lighthouse Society, accessed 22&nbsp;August 2017; [https://web.archive.org/web/20170408105558/http://uslhs.org/chronology-lighthouse-events archived] 8&nbsp;April 2017.</ref>

<ref name=tag-2017aprior>T. Tag, [http://uslhs.org/lens-use-prior-fresnel "Lens use prior to Fresnel"], U.S. Lighthouse Society, accessed 12&nbsp;August 2017; [https://web.archive.org/web/20170520114102/http://uslhs.org/lens-use-prior-fresnel archived] 20&nbsp;May 2017.</ref>

<ref name=tag-2017bfres>T. Tag, [http://uslhs.org/fresnel-lens "The Fresnel lens"], U.S. Lighthouse Society, accessed 12&nbsp;August 2017; [https://web.archive.org/web/20160722002916/http://uslhs.org/fresnel-lens archived] 22&nbsp;July 2017.</ref>

<ref name=watson-2016>B. Watson, ''Light: A Radiant History from Creation to the Quantum Age'', New York: Bloomsbury, 2016.</ref>

Line 321 ⟶ 361:

== Bibliography ==

<ref* name=crew-1900>H. Crew (ed.), [https://archive.org/details/wavetheoryofligh00crewrich ''The Wave Theory of Light: Memoirs by Huygens, Young and Fresnel''], American Book Co., 1900.</ref>

<ref* name=darrigol-2012>O. Darrigol, ''A History of Optics: From Greek antiquity to the nineteenth century'', Oxford, 2012.</ref>

* A. Fresnel (ed. H. de Senarmont, E.&nbsp;Verdet, L.&nbsp;Frenel), ''Oeuvres complètes d'Augustin Fresnel'' (3 vols.), Paris: Imprimerie impériale, 1866&ndash;70; [https://books.google.com/books?id=1l0_AAAAcAAJ v.1&nbsp;(1866)], [https://archive.org/details/oeuvrescompltes00fresgoog v.2&nbsp;(1868)], [https://archive.org/details/oeuvrescompltes01fresgoog v.3&nbsp;(1870)].

<ref* name=levitt-2013>T.H. Levitt, ''A Short Bright Flash: Augustin Fresnel and the Birth of the Modern Lighthouse'', New York: W.W.&nbsp;Norton, 2013.</ref>

* {{OL author|2296238A}}