https://doi.org/10.1351/goldbook.U06574
The process by which two photons with frequencies \(\nu _{2}\) and \(\nu _{3}\) combine in a non-linear medium to produce a higher energy photon with frequency \(\nu _{1}\) such that \(\nu _{1}=\nu _{2}+\nu _{3}\).
Notes:
- Also known as a parametric upconversion or sum frequency generation. Upconversion is the reverse process of @DT07362@.
- The efficiency of the conversion process depends on the parametric gain in the non-linear material. This in turn depends on the @P04792@ of the incident radiation, the photon frequencies, their indices of refraction in the material, and the non-linear 'hyper-susceptibility' of the material.