Ultra-high speed all-optical shift registers and their applications in OTDM networks

• Published in: Optical and quantum electronics Vol. 36; no. 11; pp. 1005 - 1053
• Main Authors: ZOIROS, K. E, HOUBAVLIS, T, KALYVAS, A. N. D. M
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.09.2004
• Subjects: Applied sciences; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Optical computers, logic elements, interconnects, switches; neural networks; Optical elements, devices, and systems; Optical telecommunications; Optics; Physics; Telecommunications; Telecommunications and information theory; Optical logic; Bit error rate; Optical memory; Non linear optics; Wavelength division multiplexing; Optical gating; Experimental study; Ultrafast optics; All optical circuit; Semiconductor optical amplifiers; Optical communication equipment; Shift register; Sagnac interferometer; Signal to noise ratio
• ISSN: 0306-8919; 1572-817X
• DOI: 10.1007/s11082-004-2040-9

All-optical shift registers are basic building modules for the development of ultra-high speed optical time division multiplexing networks. In this paper, we review the progress that has been made in this cutting-edge technology, focusing on implementations that exploit the attractive features of semiconductor optical amplifier (SOA)-based interferometric configurations. We present regenerative storage performed with an all-optical recirculating shift register with an inverter at 10 Gb/s using a SOA-assisted Sagnac switch and a second SOA to provide feedback. We demonstrate also an all-optical memory based on the SOA-assisted Ultrafast Nonlinear Interferometer capable of reading/writing 20 Gb/s packets of variable length without data inversion. These registers can find application in the development of two nontrivial complex all-optical circuits of enhanced functionality. The first is an all-optical pseudorandom binary sequence generator for which we describe an efficient design algorithm and propose ways for monitoring and verification. The second is an all-optical error counter for which we address the error detection and evaluation issues using a novel sampling technique. These circuits are key elements for the implementation of a high-speed, all-optical bit error rate tester (BERT), which has the potential to outperform its electronic equivalent and constitute a possible new product for the telecommunications industry.