Population inversion

{
  "id": "MLC-T-CHM-009276",
  "term": "Population inversion",
  "field": "Chemistry",
  "definition": "A condition in which a higher energy state of an atomic or molecular system has a greater population of particles than a lower energy state. This non-equilibrium distribution is necessary for stimulated emission to dominate over absorption, leading to light amplification. It is a prerequisite for the operation of lasers and masers.",
  "subject": "Organic and Biomolecular Chemistry",
  "references": [
    "PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2266 (https://doi.org/10.1351/pac199668122223)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/population-inversion/"
}