Theoretical Demonstration of 250 Gb/s Ultrafast All-Optical Memory Using Mach-Zehnder Interferometers with Quantum-Dot Semiconductor Optical Amplifiers

Ultrafast all-optical memory at 250 Gb/s using Mach-Zehnder interferometers (MZIs) with symmetrical quantum-dot semiconductor optical amplifiers (QDSOAs), acting as all-optical AND gate and regenerator in a loop configuration, is theoretically demonstrated for 500 loop circulations using a return-to-zero modulated format. The memory operation is examined and evaluated by the quality factor (QF), which is a more sensitive method of measuring memory quality. The obtained numerical results show that the proposed memory can be operated up to 250 Gb/s for 500 circulations with high QF.