“…Semiconductor Optical Amplifier-based Mach-Zehnder Interferometers (SOA-MZIs) have been widely used in the past years as all-optical high speed switches for signal conditioning and signal processing, mainly due to their low switching power requirements and their potential for integration (Maxwell, 2006). Using this type of switch, a set of processing operations ranging from demultiplexing (Duelk et al,1999) to regeneration ) and wavelength www.intechopen.com Advances in Optical Amplifiers 54 conversion (Nielsen et al 2003) to optical sampling (Fischer et al 2001) and optical flip-flops (Hill et al 2001, Pleros et al 2009) has been demonstrated, highlighting multi-functionality as an additional advantage of SOA-MZI devices. Within the same frame, SOA-MZI devices have proven very efficient in dealing with packet-formatted optical traffic allowing for their exploitation in several routing/processing demonstrations for optical packet or burst switched applications, performing successfully in challenging and demanding functionalities like packet envelope detection (Stampoulidis et al, 2007), packet clock recovery (Kanellos et al, 2007a), label/payload separation (Ramos et al, 2005), burst-mode reception (Kanellos et al, 2007a(Kanellos et al, , 2007b and contention resolution (Stampoulidis et al, 2007).A brief description of the most important SOA-MZI signal processing applications and their principle of operation is provided in the following paragraphs.…”