08575 IUPAC Gold Book - Bragg filter 10.1351/goldbook.08575 08575 current 1 Optical filter used, for example, to attenuate Rayleigh scattering while transmitting light subject to Raman shift. Historically, a Bragg filter was a colloidal dispersion of spheres in a regular close packed array, which selectively diffracts/reflects wavelengths that satisfy the Bragg diffraction criterion for the lattice but transmits all other wavelengths. Now largely superseded by Volume Bragg Gratings, where photo-induced modulation of the refractive index of the filter medium is used to form a volume phase hologram with reflecting planes separated by a well-defined spacing. In each case, angle tuning is used to match the laser wavelength to the Bragg diffraction condition. The filter can be manufactured either as a notch filter, which transmits wavelengths either side of the laser line, or as an edge filter, which only transmits wavelengths longer than the laser line (i.e., Raman light subject to Stokes scattering). Raman shift https://goldbook.iupac.org/terms/view/08668 Stokes scattering https://goldbook.iupac.org/terms/view/08683 light https://goldbook.iupac.org/terms/view/08264 wavelengths https://goldbook.iupac.org/terms/view/08300 PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 739 (https://doi.org/10.1515/pac-2019-0203) https://goldbook.iupac.org/terms/view/08575/html https://goldbook.iupac.org/terms/view/08575/json https://goldbook.iupac.org/terms/view/08575/plain Citation: 'Bragg filter' 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.08575 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. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . 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. 2026-06-29T22:04:10+00:00