Reducing conversion range in wavelength exchange networks

All‐optical cross‐connects need to perform switching not only in the space domain, but also in the wavelength domain. Switching in the wavelength domain requires wavelength converters (WCs), and WCs capable of simultaneously performing multiple wavelength conversions have been invented. We can use multiple stages of such WCs to form a wavelength exchange network to allow an even larger number of simultaneous wavelength conversions. However, WCs with a full conversion range are often difficult to implement. In the paper, we develop new techniques and theories that can reduce the conversion range requirement and still maintain the full connectivity of all‐optical space/wavelength switches.