All-optical Switching Networks Research Articles

Nanosecond tunable laser for the all-optical switching network.

The optically switched network can offset the increasing gap between datacenter traffic growth and electrical switch capacity due to the slowdown of Moore's law. Ultra-high-speed wavelength tunable lasers are especially vital for the high integration and performance improvement of the all-optical switching system. In this paper, a fast tunable laser based on a laser array is realized. The 2×8 matrix structure of the laser array is fabricated by the reconstruction-equivalent-chirp (REC) technique. Aiming at the 2×8 array, a drive control system is designed to provide stable and fast switching, to achieve high-speed switching of the laser wavelength, and to keep the wavelength stable after switching. The simulation and experimental results show that the switching time between any two wavelength channels of the laser is less than 10ns. The switching time of any two channels of the laser can be reduced by 2-3ns after the pre-emphasis processing of the electrical signal.

Wavelength Selective Switch-Based Clos Network: Blocking Theory and Performance Analyses

A Clos network is a classical switching network often used in conventional electrical switches. In a Wavelength Selective Switch (WSS) based Clos all-optical switching network, the wavelength dimension needs to be additionally considered. However, the conventional blocking theory of the Clos network may not be valid in this scenario and it may be necessary to conduct a theoretical study specifically for the WSS-based Clos all-optical switching network. In this paper, we derive the strictly non-blocking conditions for the WSS-based Clos network for the cases where there is no wavelength conversion, partial wavelength conversion, and full wavelength conversion. For the situation where there is service blocking, we also formulate probabilistic analytical models to estimate the blocking performance for the three types of WSS-based Clos networks. The gain of transceiver utilization achieved by the WSS-based Clos network with wavelength conversion is evaluated and compared with that of one without wavelength conversion. We also evaluate the impact of partial wavelength conversion capability on the blocking performance of a WSS-based Clos network.

A Research on Key Technologies in All-Optical Label Switching Networks

With the rapid development of Internet technology, the capacity of communication system is increasing rapidly and traditional switching technology based on optical-electrical-optical (O/E/O) conversion cannot satisfy requirements for information exchange. Construction of a high-speed, large-capacity, high-bandwidth all-optical switching network will be the future direction of communication systems. In this paper, the key technologies in all-optical label switching networks are investigated. First, five kinds of optical label technologies are studied. The principles and implementation methods of them are analyzed and compared. Then, optical switching fabrics based on different kinds of optical switches are discussed. Next, a 160Gb/s Optical Time Division Multiplexing (OTDM) signal 1 × 8 packet switching experiment is introduced. Finally, the research work is summarized, and the design of core nodes in optical packet switching network is prospected.

Adaptive Policies for Scheduling With Reconfiguration Delay: An End-to-End Solution for All-Optical Data Centers

All-optical switching networks have been considered a promising candidate for the next generation data center networks thanks to its scalability in data bandwidth and power efficiency. However, the bufferless nature and the nonzero recon- figuration delay of optical switches remain great challenges in deploying all-optical networks. This paper considers the end-to- end scheduling for all-optical data center networks with no in- network buffer and nonzero reconfiguration delay. A framework is proposed to deal with the nonzero reconfiguration delay. The proposed approach constructs an adaptive variant of any given scheduling policy. It is shown that if a scheduling policy guarantees its schedules to have schedule weights close to the MaxWeight schedule (and thus is throughput optimal in the zero reconfiguration regime), then the throughput optimality is inherited by its adaptive variant (in any nonzero reconfiguration delay regime). As a corollary, a class of adaptive variants of the well known MaxWeight policy is shown to achieve throughput optimality without prior knowledge of the traffic load. Further- more, through numerical simulations, the simplest such policy, namely the Adaptive MaxWeight (AMW), is shown to exhibit better delay performance than all prior work.

A novel wavelength conversion scheme based on a single SOA inserted MZI for all-optical switching network

A novel scheme of wavelength conversion based on single semiconductor optical amplifier (SOA) inserted Mach---Zehnder-interferometers (MZI) is proposed to resolve the optical packet contending in the paper. A signal phase adjuster is designed for MZI lower arms to change the optical signal phase difference between MZI upper arms and lower arms accurately. The SOA and input optical signal parameters are discussed and analyzed to optimize the scheme wavelength conversion performance for all-optical switching networks. Numerical analysis and simulation show that more than 20 dB contrast ratio can be achieved for the wavelength conversion at 40 Gbps. In addition, the system is simple structure, stable and photonic integratable.

A novel node architecture for all-optical switching networks

A novel node architecture for all-optical switching networks

Design of packet-switched network using optical signal processing techniques

In this paper, we design an optical packet-switched network with an optical ring resonator (ORR), a delay line decoder (DLD), and an optical address translator (OATR). The ORR can discriminate the header/payload directly in the optical domain. The DLD, together with the optical threshold device, can be used as an optical correlator for the routing control signal. The OATR uses time-slot-interchange (TSI) technology to translate the optical address for the next optical switching stages. These optical signal processing techniques can be applied to future high-speed all-optical switching networks. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 23: 104–109, 1999.