Wanyi Gu

Research and realization of OADM technology in metro optical network

Optical Add/Drop Multiplexer (OADM) is an important network element. In the ring architecture, OADM can be introduced to make efficient use of network capacity, network protection, wavelength routing and many more good features. In this paper, an OADM with high performance realized by us is demonstrated. The key technical problem , solving method and design rule for the OADM are given. The experiment results of long distance transmission by use of the OADM are illuminated by some figure . It shows that the OADM realized by us is advanced, practical, reliable, and applied in China Advanced Info-Optical Network (CAINONet).

New optical path cross-connect architecture

This paper discusses functional requirements of optical path cross-connect (OPXC) node. Generic optical path cross-connect (OPXC) node architectures are introduced, and a new OPXC node architecture is proposed. OPXC node architectures are assessed. A transport system with two new OPXC nodes and a 100km dispersion-shifted fiber are simulated. It shows that the new OPXC architecture is superior to generic OPXC architectures.

Study on Spectrum Sliced ASE Source for Injection-locking of Fabry-Pérot Laser Diodes

Recently, Fabry-Perot laser diodes (FPLDs) injection-locked by spectrum sliced amplified spontaneous emission (ASE) noise as a low cost light source for wavelength division multiplexed passive optical network (WDM-PON) has been proposed and gained much attention. Spectrum sliced ASE source inherently suffers from intensity noise (IN). This IN is relative to the filter bandwidth of a spectrum sliced ASE noise and is transferred to the output of the injection-locked FPLDs. In this paper, we experimentally investigate the impact of filter bandwidth of a spectrum sliced ASE source for injection-locking a FPLD and IN conversion effects from the spectrum sliced ASE source to the FPLD. We propose an IN suppressing method using a semiconductor optical amplifier (SOA). Experimental results show that there is an optimum bandwidth of the sliced ASE source injected into a FPLD and the output performance of the injection-locked FPLD is improved by intensity noise suppression

Novel scheme for routing optical supervisory channels adhering to OXC

One novel scheme for routing optical supervisory channels adhering to optical cross-connect (OXC) is developed in this paper. Beginning with the definition of the new frame to carry the optical channel (OCH) layer overheads, the proposed scheme processes the overhead associated the individual optical channel, which is carried by optical supervisory channel (OSC), in the similar way as the message-oriented data communication channel (DCC) in OSC. Therefore, all OCH-specified information carried by OSC can be routed by a uniform manner.

IP-based restoration algorithm for optical networks

One distributed restoration algorithm used to protect optical transport networks against network failures is proposed in the paper. The algorithm takes advantage of the existing IP protocols, and therefore it can restore the affected traffic in the distributed and efficiently manner. By carrying the wavelength availability information in protocol data unit, the algorithm can reserve the required capacities as well as search the restoration routing.

Two modules for building OADM and OXC in metro networks

One FBG-MZI-based component and one mediator are proposed in this paper. The proposed OADM building module consists of one FBG-based MZI module and one reconfigurable module, and it can add/drop or pass-by the specified wavelength. OADM created by concatenating the proposed modules, owns wavelength modularity, and can add-drop and pass-by any specified wavelengths. The mediator is one simplified 4 x 4 optical switch matrix. It can be used to interconnect multiple OADM modules to build one OXC with multiple ports.

Analysis of error detection codes in optical transport networks

It is important to resolve the questions of how many BIP bytes are required and which EDC should be adopted for performance monitoring in Optical Transport Networks (OTN). Based on the Poisson Error Model and Burst Error Model, we obtain the mathematical expressions for the probabilities of occurrence of a block error and of detecting a block error, as well as the detection efficiency. Analyses and simulations to determine the maximum BER that can be detected (i.e., the saturation BER) and the minimum detection efficiency are given. Conclusions are drawn as follows: one BIP byte per tandem connection monitoring field is adequate for performance monitoring; 2*BIP-4 EDC should be adopted to meet the requirement that the detection efficiency be no less than 90%; 8*BIP-1 EDC is acceptable if the real-time BER measurement estimate is not required.

Atomic functional model for WDM optical transport network

In this paper, atomic functional models for optical transport network are introduced. Based on the proposed atomic components for optical components, the paper addresses the method modeling optical network elements. The models of some key network elements (i.e. OXC) are also shown in the paper, and simulation results by using the created model are present also.

Functional architecture of optical channel network

Atomic functional architecture model has been accepted by ITU-T to describe the functional architecture of transport networks as well as equipment specification in an implementation independent way. With the existing functional architecture components four different solutions have been proposed to model the complex optical channel (OCh) layer network. One approach is to assign 3-R to the OMS/OCh adaptation function; the second approach is to introduce dedicated transparent layers or to split single OCh layer into several sub-layers; the third is to be deployed by using an abstract characteristic information (CI) definition; the last is using super layer architecture component. This paper analyzes these four methods and presents a new approach by introducing virtual layer network and virtual CI. Virtual adaptation, virtual connection point and virtual link connection are also introduced in order to cover the different transparent connections within a layer network. In addition, examples of using virtual layer component to model the OADM with transparent pass-through and to provide the necessary transparent connections for optical network elements are presented in this paper.

Nonlinear effects in WDM systems

A synthetical equation set about optical fiber nonlinear in WDM transmission system is proposed in this paper. A supplementary Split-Step Fourier Method to solve the equation is proposed too. The equation and its numerical method can be used to analyze different fiber nonlinear effects, which will also do great help to simulating and analyzing the performance of WDM transmission system.