**2.2 Realization of SOA-based Wavelength Converters**

In packet switching networks, tuneable wavelength converters can be used to resolve packet contention and overcome the optical buffering problem. An example of SOA-based Wavelength Converter is illustrated in Fig. 4. It is referred to as Delayed Interference Signal WCs (DISCs) and has been proposed in (Sakaguchi et al., 2007). DISC employs nonlinear effect in SOA and utilizes an SOA and an OBF placed at the amplifier output. It can be constructed by using commercially available fiber-pigtailed components. It has a simple configuration and allows photonic integration.

Fig. 4. Realization of an all-optical wavelength converter by using a Delayed-Interference Signal Wavelength Converter (DISC).
