Hold on characteristics of amplified recirculating structures

Summary form only given. A function that is becoming interesting in photonic processing is the generation of a step-like signal under the trigger of an optical pulse. Such a function, for instance, could be the basis for the re-generation of a short-cw signal in optical header processing or it could be useful for creating an optical gate for sampling operations. A step-like signal is achievable by amplified recirculating structures through their hold-on characteristic. The aim of this communication is to present analysis and experimentation of the performances of recirculating structures amplified by two types of active devices: EDFA and SOA. The general scheme of the recirculating structure contains an optical amplifier and two ports for the entrance of two different pulses, the set signal for the hold-on function and the reset signal for the output switching. The hold-on function is activated directly by the set optical pulse and is obtained by overlapping the same pulse recirculating in the structure. Its duration is upper limited by the evolution of the SNR in the circuit. The switch-off is achieved by deploying the amplifier gain compression induced by the reset optical pulse.