A wavelength converter is a component in optical networks where the light signal of a certain wavelength is converted into another wavelength. As with the mixing of RF signals, the wavelength converter uses the non- linearity of a laser amplifier to transform the optical signals into a different optical wave spectrum.
In the wavelength converter, the optical signal present at the input is mixed with a mixing frequency and thus transferred to another wavelength band. Entire wavelength bands can also be converted to another optical band.
Three different methods are used for wavelength conversion: Cross PhaseModulation(XPM), Cross Gain Modulation(XGM) and Four Wave Mixing( FWM). In addition to the methods mentioned, there is also that of optical-electrical-optical conversion in conjunction with 3R regeneration.