downconversion

https://doi.org/10.1351/goldbook.DT07362
Process by which a photon with frequency ν1 interacts with a non-linear medium and splits into two simultaneously emitted photons with frequencies ν2 and ν3 so that the energy is conserved: ν1=ν2+ν3
Notes:
  1. Also known as a parametric downconversion.
  2. The efficiency of the conversion process depends on the parametric gain in the non-linear material. This in turn depends on the power of the incident radiation, the photon frequencies, their indices of refraction in the material, and the non-linear 'hyper-susceptibility' of the material.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 326 [Terms] [Paper]