Realization of all-optical wavelength converter based on directionally coupled semiconductor optical amplifiers

We propose a novel all-optical wavelength converter based on directionally coupled (DC) semiconductor optical amplifiers (SOA) and simulate its charac teristics using a simple model to find out such advantages as extinction en hancement and digital response. We then fabricate devices in the 1.55-mu m band, and successfully demonstrate the wavelength conversion operation with the above-mentioned advantages, Very compact size and no need of active/pa ssive integration are other significant merits of DC SOA's.