OptiSystem Applications

Stability of solitons in birefringent optical fibers

This lesson demonstrates that the Kerr nonlinearity, which stabilizes solitons against spreading due to GVD, also stabilizes them against splitting due to birefringence [1] – [3]. The “single-mode” fibers are actually bimodal because of the presence of birefringence. This means that the group velocity is different for pulses polarized along the two principal axes. If…

Orthogonal Raman gain

This lesson demonstrates the energy exchange between two optical solitons with orthogonal polarizations associated with the orthogonal Raman gain [1]. Using equations (17a) from the technical description of the Nonlinear dispersive fiber component it can be shown [1] that the energy exchange between two solitons: where P1 > > P2 and Δ ω > 0…

Average Soliton Regime

This lesson demonstrates the average soliton regime at 10 Gb/s transmission over a 500 km optical link consisting of SMF. Figure 1 shows the layout that was used. Figure 1: Average soliton regime layout Figure 2 shows the global and pulse parameters used to achieve transmission at 10 Gb/s. Figure 2: Simulation and Main parameters…

SOA as In-line Amplifier in Soliton Communication Systems

One possible way to upgrade an existing network from previously installed standard optical fibers is to exploit the 1.3 mm optical window, where the step index fibers have a zero-dispersion wavelength using SOA. The advantages of using SOA as in-line single-channel optical amplifiers are: low dispersion of the SMF at this carrier wavelength attractive features…

Power Level Management in Optical Metro Networks

Design without amplification In this example, our goal is to design a basic transparent ring network without amplification and discover the power related issues. Metro networks using ring topology are expected to have more dynamic traffic patterns compared to most long-haul networks. They are also expected to have optically transparent nodes with a minimum number…

Migrating to 10Gbps in Metro Networks

In this example, we will investigate the issues at high data bit rate, particularly 10 Gbps (OC-192) systems in metro area ring networks. At higher bit rates, in addition to loss compensation, we may also need to consider the chromatic dispersion compensation. Different options related to dispersion and initial chirp will be investigated. For this…

Negative Dispersion Fiber for Metro Networks

In this example, we compare two types of fibers, Corning’s MetroCor and SMF-28 fibers for metro network applications. MetroCor Fiber has a negative dispersion, whereas SMF-28 has a positive dispersion in the EDFA bands. Dispersion characteristics of these two fibers are shown in Figure 1. For metro applications, directly modulated lasers (DMLs) are preferred because…

Interchannel Crosstalk in Metro Networks

A particular signal can accumulate cross-talk from different elements and channels over the network. Cross-talk can be reduced by using several techniques such as wavelength dilation or filter cascading. In this example, we will investigate the effect of interchannel cross-talk at ADM to a ring network.

WDM Ring – Wavelength Independent Subscriber Equipment

In this example, we will show realization of a WDM ring network using wavelength independent subscriber equipment to share bandwidth [1]. The metro-ring network we modeled operates with 2 wavelength carriers as shown in Figure 1. In this configuration, several subscribers share the bandwidth. For illustration purposes, the network contains one Network Node (NN) and…

Digital Modulation – DPSK

The purpose of this lesson is to demonstrate how to design an 8 DPSK pulse generator using the OptiSystem component library. This tutorial includes references to project files that demonstrate some of the steps presented here. Refer to the end of the tutorial for the project file names. You should use the OptiSystem Component Library…