{"term":{"id":"08655","title":"ordinary wave","longtitle":"IUPAC Gold Book - ordinary wave","doi":"10.1351\/goldbook.08655","code":"08655","status":"current","synonym":"<em>synonym<\/em>: ordinary ray","definitions":[{"id":1,"text":"In a uniaxial crystal electromagnetic radiation with electric vector perpendicular to the optic axis and which obeys the normal laws of refraction.","notes":{"1":"In uniaxial crystals the optic axis coincides with the symmetry axis. The refractive index of the crystal is the same in all directions perpendicular to the optic axis but is different along the optic axis. Consequently, electromagnetic rays or waves that do not travel along the optic axis experience different refractive indices in different directions perpendicular to their direction of propagation. Two waves result, one has its electric vector perpendicular to the optic axis and forms the ordinary wave. The other is the extraordinary wave."},"links":[{"term":"electromagnetic radiation","url":"https:\/\/goldbook.iupac.org\/terms\/view\/08242"},{"term":"extraordinary wave","url":"https:\/\/goldbook.iupac.org\/terms\/view\/08600"}],"sources":["PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 758 (https:\/\/doi.org\/10.1515\/pac-2019-0203)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/08655\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/08655\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/08655\/plain"},"citation":"Citation: 'ordinary wave' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351\/goldbook.08655","license":"The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/) for individual terms.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.","accessed":"2026-07-27T02:03:27+00:00"}}