Time-domain response to ps optical pulse trigger of an all-optical flip-flop based on semiconductor ring laser

摘要

Monolithic Semiconductor Ring Lasers (SRLs) are promising devices for all-optical memory and all-optical switching applications, as they can operate in a directional bistable regime where only one directional mode (clockwise or anticlockwise) is active at one time. The unidirectional bistable regime can be naturally associated to a binary logic, and the SRL represents an elementary digital memory cell that can be written ail-optically, realising the function of an all-optical flip-flop. In fact, the direction of operation can be switched by injecting an external optical signal pulse into the SRL through one of the 4 input/output ports.Directional switching of the SRL-based all-optical flip-flop has been demonstrated by injecting optical pulses with 5 ps duration into one of the four input/output ports. The required switching energy is around 100 fJ, and the swiching time is between 100 and 200 ps. The same function has been demonstrated by injecting 400 ps pulses as optical trigger.