Anomalous dispersion

{
  "id": "MLC-T-CHM-000634",
  "term": "Anomalous dispersion",
  "field": "Chemistry",
  "definition": "The phenomenon where the refractive index of a medium decreases with increasing frequency (decreasing wavelength) of electromagnetic radiation in a specific absorption region. This behavior is contrary to normal dispersion, where the refractive index increases with frequency. It is observed near absorption bands of a material.",
  "subject": "Analytical Chemistry",
  "see_also": [
    "normal dispersion of the refractive index",
    "wavenumber in vacuum"
  ],
  "references": [
    "PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 738 (https://doi.org/10.1515/pac-2019-0203)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/anomalous-dispersion/"
}