All-Optical Digital Circuits Exploiting SOA-Based Loop Memories

• Published in: IEEE journal of selected topics in quantum electronics Vol. 18; no. 2; pp. 847 - 858
• Main Authors: Berrettini, G., An Truong Nguyen, Lazzeri, E., Meloni, G., Scaffardi, M., Potì, L., Bogoni, A.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-03-2012; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Buffer memories; linear feedback shift register; Optical attenuators; Optical buffering; Optical feedback; Optical packet switching; Optical saturation; Random access memory; semiconductor optical amplifier; shift register
• ISSN: 1077-260X; 1558-4542
• DOI: 10.1109/JSTQE.2011.2138120

All-optical digital circuits based on loop memories are demonstrated. These circuits are a variable optical buffer, an optical random access memory, an optical shift register, and an optical linear feedback shift register. Buffers are employed in network nodes to solve the contentions without loosing information. Shift registers are used for error detection and correction techniques. Linear feedback shift registers are employed for generation of pseudo-random bit sequences, data scrambling, and encryption/decryption of information in secure communication systems. Since the role of optical processing is gradually increasing within the communication systems, the possibility to store information directly in the optical domain can lead to a systems simplification and to a performance improvement. In order to make the schemes suitable for practical applications, optical integration is necessary. The use of semiconductor optical amplifier as gain element into the memory loop allows all the proposed schemes to be integrated.