Editing Optical rotation (section)

== History ==
{{See also|Physical crystallography before X-rays#Rotary polarization}}
[[Image:TartrateCrystal.svg|thumb|The two asymmetric crystal forms, dextrorotatory and levorotatory, of [[tartaric acid]].]]
[[Image:Sucrose solution and polaroid (optical activity).jpg|thumb|Sucrose solution concentration measuring experiment, demonstrating optical rotation.]]
The rotation of the orientation of [[linear polarization|linearly polarized]] light was first observed in 1811 in [[quartz]] by French physicist [[François Arago]].<ref>Arago (1811) [https://babel.hathitrust.org/cgi/pt?id=ucm.5326746608;view=1up;seq=103 "Mémoire sur une modification remarquable qu'éprouvent les rayons lumineux dans leur passage à travers certains corps diaphanes et sur quelques autres nouveaux phénomènes d'optique"] (Memoir on a remarkable modification that light rays experience during their passage through certain translucent substances and on some other new optical phenomena), ''Mémoires de la classe des sciences mathématiques et physiques de l'Institut Impérial de France'', 1st part : 93–134.</ref> In 1820, the English astronomer [[John Herschel|Sir John F.W. Herschel]] discovered that different individual quartz crystals, whose crystalline structures are mirror images of each other (see illustration), rotate linear polarization by equal amounts but in opposite directions.<ref>Herschel, J.F.W. (1820) [https://babel.hathitrust.org/cgi/pt?id=nyp.33433004518324;view=1up;seq=87 "On the rotation impressed by plates of rock crystal on the planes of polarization of the rays of light, as connected with certain peculiarities in its crystallization,"] ''Transactions of the Cambridge Philosophical Society'', '''1''' :  43–51.</ref> [[Jean Baptiste Biot]] also observed the rotation of the axis of polarization in certain liquids<ref>Biot, J. B. (1815) [https://www.biodiversitylibrary.org/item/26553#page/196/mode/1up "Phenomene de polarisation successive, observés dans des fluides homogenes"] (Phenomenon of successive polarization, observed in homogeneous fluids), ''Bulletin des Sciences, par la Société Philomatique de Paris'', 190–192.</ref> and vapors of organic substances such as [[turpentine]].<ref>Biot (1818 & 1819) "Extrait d'un mémoire sur les rotations que certaines substances impriment aux axes de polarisation des rayons lumineux" (Extract from a memoir on the [optical] rotations that certain substances impress on the axes of polarization of light rays), ''Annales de Chimie et de Physique'', 2nd series, '''9''' :  [https://babel.hathitrust.org/cgi/pt?id=hvd.hx3dvg;view=1up;seq=384 372–389]; '''10''' :  [https://babel.hathitrust.org/cgi/pt?id=ien.35556014127617;view=1up;seq=67 63–81]; for Biot's experiments with turpentine vapor (''vapeur d'essence de térébenthine''), see pp. 72–81.</ref> In 1822, [[Augustin-Jean Fresnel]] found that optical rotation could be explained as a species of [[birefringence]]: whereas previously known cases of birefringence were due to the different speeds of light polarized in two perpendicular planes, optical rotation was due to the different speeds of right-hand and left-hand circularly polarized light.<ref name=fresnel-1822z>A. Fresnel, "Mémoire sur la double réfraction que les rayons lumineux éprouvent en traversant les aiguilles de cristal de roche suivant les directions parallèles à l'axe", read 9&nbsp;December 1822; printed in H.&nbsp;de Senarmont, E.&nbsp;Verdet, and L.&nbsp;Fresnel (eds.), ''Oeuvres complètes d'Augustin Fresnel'', vol.&nbsp;1 (1866), pp.{{nnbsp}}731–751; translated as "Memoir on the double refraction that light rays undergo in traversing the needles of quartz in the directions parallel to the axis", {{Zenodo|4745976}}, 2021 (open&nbsp;access); especially §13.</ref> Simple [[polarimeter]]s have been used since this time to measure the concentrations of simple sugars, such as [[glucose]], in solution. In fact one name for <small>D</small>-glucose (the biological isomer), is ''dextrose'', referring to the fact that it causes linearly polarized light to rotate to the right or [[wiktionary:dexter|dexter]] side. In a similar manner, levulose, more commonly known as [[fructose]], causes the [[plane of polarization]] to rotate to the left. Fructose is even more strongly levorotatory than glucose is dextrorotatory. [[Inverted sugar syrup|Invert sugar syrup]], commercially formed by the [[hydrolysis]] of [[sucrose]] syrup to a mixture of the component simple sugars, fructose, and glucose, gets its name from the fact that the conversion causes the direction of rotation to "invert" from right to left.

In 1849, [[Louis Pasteur]] resolved a problem concerning the nature of [[tartaric acid]].<ref>Pasteur, L. (1850) [https://babel.hathitrust.org/cgi/pt?id=hvd.hx3dy7;view=1up;seq=66 "Recherches sur les propriétés spécifiques des deux acides qui composent l'acide racémique"] (Researches on the specific properties of the two acids that compose the racemic acid), ''Annales de chimie et de physique'', 3rd series, '''28''' :  56–99; see also appendix, pp. 99–117.</ref> A solution of this compound derived from living things (to be specific, [[Lees (fermentation)|wine lees]]) rotates the plane of [[Polarization (waves)|polarization]] of light passing through it, but tartaric acid derived by [[chemical synthesis]] has no such effect, even though its reactions are identical and its elemental composition is the same. Pasteur noticed that crystals of this compound come in two asymmetric forms that are mirror images of one another. Sorting the crystals by hand gave two forms of the compound: Solutions of one form rotate polarized light clockwise, while the other form rotate light counterclockwise.  An equal mix of the two has no polarizing effect on light. Pasteur deduced that the molecule in question is asymmetric and could exist in two different forms that resemble one another as would left- and right-hand gloves, and that the organic form of the compound consists of purely the one type.

In 1874, [[Jacobus Henricus van 't Hoff]]<ref>van 't Hoff, J.H. (1874) [https://babel.hathitrust.org/cgi/pt?id=hvd.32044106337231;view=1up;seq=479 "Sur les formules de structure dans l'espace"] (On structural formulas in space),  ''Archives Néerlandaises des Sciences Exactes et Naturelles'', '''9''' :  445–454.</ref> and [[Joseph Achille Le Bel]]<ref>Le Bel, J.-A. (1874) [https://babel.hathitrust.org/cgi/pt?id=hvd.hc1j13;view=1up;seq=345 "Sur les relations qui existent entre les formules atomiques des corps organiques et le pouvoir rotatoire de leurs dissolutions"] (On the relations that exist between the atomic formulas of organic substances and the rotatory power of their solutions), ''Bulletin de la Société Chimique de Paris'', '''22''' : 337–347.</ref> independently proposed that this phenomenon of optical activity in carbon compounds could be explained by assuming that the 4 saturated chemical bonds between carbon atoms and their neighbors are directed towards the corners of a regular tetrahedron. If the 4 neighbors are all different, then there are two possible orderings of the neighbors around the tetrahedron, which will be mirror images of each other. This led to a better understanding of the three-dimensional nature of molecules.<ref name="meso"> Note: In accordance with this theory, because there are two asymmetric carbon centers in tartaric acid, there is a third ''meso'' form, which has no optical activity. See the tartaric acid article for more. </ref>

In 1898, [[Jagadish Chandra Bose]] described the ability of twisted artificial structures to rotate the polarization of [[microwave]]s.<ref>{{Cite journal|last = Bose| first =Jagadis Chunder| title =On the Rotation of Plane of Polarisation of Electric Waves by a Twisted Structure| year =1898| doi =10.1098/rspl.1898.0019| jstor =115973|journal = Proceedings of the Royal Society|volume = 63| issue =389–400| pages =146–152| s2cid =89292757}}</ref> In 1914, [[Karl F. Lindman]] showed the same effect for an artificial [[Composite material|composite]] consisting of randomly-dispersed left- or right-handed wire [[Helix|helices]] in cotton.<ref>{{cite journal |last1=Lindman |first1=Karl F. |title=Om en genom ett isotropt system av spiralformiga resonatorer alstrad rotationspolarisation av de elektromagnetiska vågorna |journal=Öfversigt af Finska Vetenskaps-Societetens Förhandlingar |date=1914 |volume=57 | issue=3 |url=https://commons.wikimedia.org/wiki/File:%C3%96fversigt_af_Finska_vetenskaps-societetens_f%C3%B6rhandlingar_(IA_fversigtaffins57suom).pdf |language=Swedish}}</ref><ref>{{cite journal |last1=Lindman |first1=Karl F. |title=Über eine durch ein isotropes System von spiralförmigen Resonatoren erzeugte Rotationspolarisation der elektromagnetischen Wellen |date=1920 |volume=368 |issue=23 |pages=621–644 |doi=10.1002/andp.19203682303 | journal=[[Annalen der Physik]] |bibcode=1920AnP...368..621L |language=German}}</ref><ref>{{cite journal |last1=Lindman |first1=Karl F. |title=Über die durch ein aktives Raumgitter erzeugte Rotationspolarisation der elektromagnetischen Wellen |date=1922 |volume=374 |issue=20 |pages=270–284 |doi=10.1002/andp.19223742004 | journal=[[Annalen der Physik]] |bibcode=1922AnP...374..270L |language=German}}</ref><ref>{{cite journal |last1=Lindell |first1=I. V. |last2=Sihvola |first2=A. H. |last3=Kurkijarvi |first3=J. |title=Karl F. Lindman: the last Hertzian, and a harbinger of electromagnetic chirality |journal=IEEE Antennas and Propagation Magazine |date=June 1992 |volume=34 |issue=3 |pages=24–30 |doi=10.1109/74.153530 |bibcode=1992IAPM...34...24L |url=https://ieeexplore.ieee.org/document/153530|url-access=subscription }}</ref> Since the early 21st century, the development of artificial materials has led to the prediction<ref>{{Cite journal| last = Svirko| first =Y.|author2=Zheludev, N. I. |author3=Osipov, M.| title =Layered chiral metallic microstructures with inductive coupling| journal =[[Applied Physics Letters]]| volume =78| page =498| year =2001| issue =4| doi =10.1063/1.1342210| bibcode =2001ApPhL..78..498S}}</ref> and realization<ref>{{Cite journal| last = Kuwata-Gonokami| first =M.|author2=Saito, N. |author3=Ino, Y. |author4=Kauranen, M. |author5=Jefimovs, K. |author6=Vallius, T. |author7=Turunen, J. |author8=Svirko, Y. | title =Giant Optical Activity in Quasi-Two-Dimensional Planar Nanostructures| journal =Physical Review Letters| volume =95| page =227401| year =2005| issue =22| doi =10.1103/PhysRevLett.95.227401| pmid =16384264| bibcode =2005PhRvL..95v7401K}}</ref><ref>{{Cite journal| last = Plum| first =E.|author2=Fedotov, V. A. |author3=Schwanecke, A. S. |author4=Zheludev, N. I. |author5=Chen, Y. | title =Giant optical gyrotropy due to electromagnetic coupling| journal =Applied Physics Letters| volume =90| page =223113| year =2007| issue =22| doi =10.1063/1.2745203| bibcode =2007ApPhL..90v3113P}}</ref> of chiral metamaterials with optical activity exceeding that of natural media by orders of magnitude in the optical part of the spectrum. Extrinsic chirality associated with oblique illumination of metasurfaces lacking two-fold rotational symmetry has been observed to lead to large linear optical activity in transmission<ref>{{Cite journal| last = Plum| first =E.|author2=Fedotov, V. A. |author3=Zheludev, N. I.  | title =Optical activity in extrinsically chiral metamaterial| journal =Applied Physics Letters| volume =93| page =191911| year =2008| issue =19| doi =10.1063/1.3021082 | arxiv =0807.0523| bibcode =2008ApPhL..93s1911P| s2cid =117891131| url =https://eprints.soton.ac.uk/65831/1/4221.pdf}}</ref> and reflection,<ref>{{Cite journal| last = Plum| first =E.|author2=Fedotov, V. A. |author3=Zheludev, N. I.  | title =Specular optical activity of achiral metasurfaces| journal =Applied Physics Letters| volume =108| page =141905| year =2016| issue =14| doi =10.1063/1.4944775 | bibcode =2016ApPhL.108n1905P| hdl =10220/40854| url =https://eprints.soton.ac.uk/389739/1/specular%2520optical%2520activity%25207rev.pdf}}</ref> as well as nonlinear optical activity exceeding that of lithium iodate by 30 million times.<ref>{{Cite journal| last = Ren| first =M.|author2=Plum, E. |author3=Xu, J. |author4=Zheludev, N. I. | title =Giant nonlinear optical activity in a plasmonic metamaterial| journal =Nature Communications| volume =3| page =833| year =2012| doi =10.1038/ncomms1805 | pmid =22588295| bibcode =2012NatCo...3..833R| doi-access =free}}</ref>

In 1945, Charles William Bunn<ref>{{cite book |last=Bunn |first= C. W.|year=1945 |title=Chemical Crystallography |location=New York |publisher=Oxford University Press |page=88}}</ref> predicted optical activity of achiral structures, if the wave's propagation direction and the achiral structure form an experimental arrangement that is different from its mirror image. Such optical activity due to [[Chirality (electromagnetism)#Extrinsic 3d chirality|extrinsic chirality]] was observed in the 1960s in liquid crystals.<ref>{{cite journal|author=R. Williams|doi=10.1103/PhysRevLett.21.342|title=Optical Rotatory Effect in the Nematic Liquid Phase of p-Azoxyanisole|journal=Physical Review Letters|volume=21|page=342|year=1968|issue=6|bibcode=1968PhRvL..21..342W }}</ref><ref>{{cite journal|author=R. Williams|doi=10.1063/1.1671194|title=Optical-rotary power and linear electro-optic effect in nematic liquid crystals of p-azoxyanisole|journal=Journal of Chemical Physics|volume=50|page=1324|year=1969|issue=3|bibcode=1969JChPh..50.1324W }}</ref>

In 1950, [[Sergey Vavilov]]<ref>{{cite book |last=Vavilov |first= S. I.|year=1950 |title=Mikrostruktura Sveta (Microstructure of Light) |location=Moscow |publisher=USSR Academy of Sciences Publishing }}</ref> predicted optical activity that depends on the intensity of light and the effect of nonlinear optical activity was observed in 1979 in [[lithium iodate]] crystals.<ref>{{Cite journal| last = Akhmanov| first =S. A.|author2=Zhdanov, B. V. |author3=Zheludev, N. I. |author4=Kovrigin, A. I. |author5=Kuznetsov, V. I. | title =Nonlinear optical activity in crystals| journal =JETP Letters| volume =29| page =264| year =1979}}</ref>

Optical activity is normally observed for transmitted light. However, in 1988, M. P. Silverman discovered that polarization rotation can also occur for light reflected from chiral substances.<ref>{{Cite journal| last = Silverman| first =M.|author2=Ritchie, N. |author3=Cushman, G. |author4=Fisher, B. | title =Experimental configurations using optical phase modulation to measure chiral asymmetries in light specularly reflected from a naturally gyrotropic medium | journal =Journal of the Optical Society of America A| volume =5| page =1852| year =1988| issue =11| doi =10.1364/JOSAA.5.001852 | bibcode =1988JOSAA...5.1852S}}</ref> Shortly after, it was observed that chiral media can also reflect left-handed and right-handed circularly polarized waves with different efficiencies.<ref>{{Cite journal| last = Silverman| first =M.|author2=Badoz, J. |author3=Briat, B.| title =Chiral reflection from a naturally optically active medium  | journal =Optics Letters| volume =17| page =886| year =1992| issue =12| doi =10.1364/OL.17.000886 | pmid =19794663| bibcode =1992OptL...17..886S}}</ref> These phenomena of specular circular birefringence and specular circular dichroism are jointly known as specular optical activity. Specular optical activity is very weak in natural materials.