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

Abstract

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.Key words: all-optical bit error rate tester, all-optical error counter, all-optical pseudorandom binary sequence, all-optical shift register, semiconductor optical amplifier (SOA), SOA-assisted interferometric switch

All-optical Multiplication with the help of Semiconductor Optical Amplifier—assisted Sagnac Switch

“…Unsaturated small amplifier gain (G ss ) of SOA is related with injection current (I ) and carrier lifetime (τ e ) by the formula [27]:…”

“…Application of TOAD in ultrafast all-optical switching has received a great deal of interest in the last few years because of its simplicity and low switching energy [19][20][21][22][23][24][25][26][27][28][29][30][31][32]. Sokoloff et al demonstrated a new device, the terahertz optical asymmetric demultiplexer (TOAD) capable of demultiplexing data at 50 Gbits/s [4].…”

High Speed All-Optical Logic Gate Using QD-SOA and its Application

“…It thus received wide application, including in simulation of noise in signal transmission, data encryption/decryption, and in bit error rate testers (BERT) [34]. The recent achievements in photonics signal processing spurred more interest towards realizing high speed all-optical PRBS generation.…”

On the Feasibility of 320 Gb/S All-Optical and Gate Using Quantum-Dot Semiconductor Optical Amplifier-Based Mach-Zehnder Interferometer

“…In particular the AND gate is indispensable for achieving this goal as it is involved in the accomplishment of numerous tasks in the optical domain both in fundamental and system-oriented level, such as buffering [2], address comparison [3], add-drop multiplexing [4], packet clock and data recovery [5], packet header and payload separation [6], binary pattern recognition [7], binary counting [8], analog-to-digital conversion [9], digital encoding and comparison [10], data regeneration [11], waveform sampling [12], half addition [13], multiplication [14], construction of other logic gates [15] and of combinational logic circuits [16]. Given its important, multi-lateral role the AND gate has attracted intense research interest and among the technological options that exist for its implementation those that exploit a semiconductor optical amplifier (SOA) are well established [17].…”