SOA tutorial

tutorialSOAs offer a key technology for amplification, switching, wavelength conversion, and regeneration in optical networks.tral active layer is based on aseparate confinement het-erostructure (SCH) and consists ofa 0.2-µm-thick tensile bulk activelayer embedded between two 0.1-µm-thick quaternary layers. It is tapered over alength of 150 µm, which allows optical cou-pling to an underlying passive waveguide. Thistype of structure provides a high optical confine-ment factor because of index mismatch between theBy Jean-Jacques Bernardlayers in the gain section, together with a large spot sizeand Monique Renaud, Alcatelat the facets for achieving a high chip-to-fiber couplings bandwidth demand rises, the con- efficiency.struction of optical packet-switchingAnodes targeting optical routers would The key parameters required for an SOA include:-4benefit from fast optical switches. Semiconductor- • residual reflectivity of less than 10 to ensure a gain rippleoptical-amplifier (SOA) technology provides this high-speed below 0.5 dBswitching capability as well as gain, high extinction ratio, and • low optical loss to achieve a net gain as high as 30 dBhigh integration potential. Moreover, it is a key technology for • high material gain to allow low-drive current operation (20 toseveral other functions, including all-optical wavelength con- 30 dB fiber-to-fiber gain for a 100-mA drive current)version, regeneration, wavelength selection, booster and ...