Teck Yoong Chai

Switchable and tunable multiwavelength erbium-doped fiber laser with fiber Bragg gratings and photonic crystal fiber

We propose and report on a novel multiwavelength-switchable-tunable erbium-doped fiber laser with excellent stability and uniformity based on four-wave mixing (FWM) in a highly nonlinear photonic crystal fiber. By adjusting the attenuators, the single, dual, or triple wavelengths can be lasing simultaneously. Under the influence of the FWM, the spectrum is stabilized and the uniformity is less than 0.6 dB.

Performance study on a WDM packet switch with limited-range wavelength converters

We consider a slotted WDM packet switch with limited-range wavelength converters. The performance of this switch is studied using simulations with various types of data traffic. Results show that the slotted WDM packet switch with a small range of wavelength conversion capability can achieve a performance close to that of a switch with the full range of wavelength conversion capability.

Efficient heuristic algorithms for light-path routing and wavelength assignment in WDM networks under dynamically varying loads

This paper presents heuristic algorithms that may be used for light-path routing and wavelength assignment in optical WDM networks under dynamically varying traffic conditions. We consider both the situations where the wavelength continuity constraint is enforced or not enforced along a light-path. The performance of these algorithms has been studied through simulations. We also compare their performance with that of a simpler system that uses fixed shortest-path routing. Our proposed algorithms provide lower blocking probabilities and are simple enough to be applied for real time network control and management. The heuristic algorithms are computationally simple and efficient to implement and provide good wavelength utilisation leading to efficient usage of the networks resources.

Operation of WDM networks with different wavelength conversion capabilities

We study the impact of wavelength conversion capability on wavelength routing WDM networks with fixed shortest-path routing. We propose a method for implementing wavelength routing in a WDM network with partial wavelength conversion capability. Simulation results show that such partial wavelength conversion networks provide a performance in between that of wavelength continuous networks and those with full conversion capability. In addition, it can be seen that only limited wavelength conversion capability is enough to provide a performance close to that of a network with full conversion. Analytical and simulation bounding results for the full and no conversion cases have also been provided.

Crosstalk analysis for limited-wavelength-interchanging cross connects

Identifies crosstalk sources in limited-wavelength-interchanging cross connects (L-WIXC) and calculates the power penalty imposed by this. Specifications for the components used in the L-WIXCs can then be determined for obtaining a specified level of system performance.

Inband crosstalk analysis of optical cross-connect architectures

In this paper, inband crosstalk in several important classes of optical cross-connect (OXC) architectures is studied. We derive the expression for the power penalty imposed by crosstalk so that the various OXC architectures can be evaluated in a systematic way. This, in turn, enables us to study the relation between crosstalk and the component requirement.

Array interconnection for rearrangeable 2-D MEMS optical switch

Two-dimensional (2-D) microelectromechanical systems (MEMS) optical switches can be constructed by arranging the MEMS-actuated micromirrors as an array. We consider here the switching capability, routing, and optimization of the rectangular array interconnection on which the capability and efficiency of 2-D MEMS switches depend. The switching capability of a rectangular array is proved analytically. Two routing algorithms, namely, the most-bend routing and the least-bend routing, are developed, which, respectively, maximize and minimize the number of 2 /spl times/ 2 switches in the bend state. A method of counting the number of permutations realizable with a given number of switches in the bend state is proposed to evaluate the performance of both routing schemes. The understanding of the underlying interconnection pattern enables us to study the problem of constructing rearrangeable optical switches of arbitrary size.

Performance analysis under dynamic loading of wavelength continuous and non-continuous WDM networks with shortest-path routing

The performance of WDM networks using shortest path routing is studied under wavelength continuous (WC) and non-continuous (NWC) constraints and dynamic traffic loading. Approximate analytical models are presented for the performance studies of such systems. Results of numerical calculations based on these models and simulations are given for different network topologies for the purposes of comparison. These analytical and simulation results are used to study the performance of these WDM networks under dynamic traffic loading. Copyright

The impact of number of transceivers and their tunabilities on WDM network performance

For all-optical WDM networks, we study the impact of the number of transceivers and their tunabilities on network performance. Results have been obtained through simulations for networks with different topologies. We find that a network with a limited number of transceivers in each node and limited transceiver tunability can still perform close to one equipped with a full number of fully tunable transceivers.

Approximate analysis of limited-range wavelength conversion all-optical WDM networks

We use the analytical model for multi-fibre WDM networks to approximately analyse the network performance of limited-range wavelength conversion WDM networks. In addition, we develop a simple analytical model for multi-fibre networks with limited-range wavelength conversion capability by combining the multi-fibre network model and the limited-range wavelength conversion network model. Extensive calculations based on these models have been done for networks with a single light-path and with different wavelengths on each link. Based on the results obtained, we conclude that our analytical model is simple and yet can effectively analyse the impact of wavelength conversion range and fibre number on the network performance.