# Optical downconverter

Optical DownConverter (ODC) is an example of a non-linear optical process, in which two beams of light of different frequencies ${\displaystyle \omega _{1}}$ and ${\displaystyle \omega _{2}}$ interact, creating microwave with frequency ${\displaystyle \omega _{3}=\omega _{1}-\omega _{2}}$. It is a generalization of microwave. In the latter, ${\displaystyle \omega _{1}=\omega _{2}}$, both of which can be provided by a single light source. From a quantum mechanical perspective, ODC can be seen as result of deferencing two photons to produce a microwave. Since the energy of a photon is given by
${\displaystyle E_{\nu }=\hbar \omega ,}$
the frequency summing ${\displaystyle \omega _{3}=\omega _{1}-\omega _{2}}$ is simply a statement that energy is conserved.