WDM systems

Comparison of RZ and NRZ Modulation Formats for 40 Gb/s Systems

Most installed fibers are standard single mode fibers (SMF) with high group velocity dispersion values ( ~ 16ps/nm/km ) at 1.55 µm. To achieve a good level of bit-error- rate (BER) as well as to enable larger repeater spacing and larger signal-to-noise ratio (SNR) in this type of fiber, it is very important to consider…

16 Channel WDM System Design

Optical System - Figure 1 Single channel system layout

This lesson demonstrates the basic features of a typical WDM optical communication system and shows the basic design steps with OptiSystem. In this lesson we will develop a simple, realistic WDM communication system. The performance of the system will be shown and compared with published results. The impact of various physical effects accompanying the light…

WDM Components – Tunable Filters

Optical System- Figure 1 - Fabry-Perot Filter

OptiSystem component library includes different types of components for WDM systems, the tunable optical filters include Fabry-Perot filters, Mach-Zehnder interferometers, and grating based filters. Fabry-Perot filters Fabry-Perot filter.osd shows the transmission of a Fabry-Perot filter used as a tunable optical filter (see Figure 1). The frequency spacing between two successive transmission peaks is know as…

WDM Components – AWG Demultiplexer

Optical System - Figure 1 - AWG Demultiplexer

Fiber Bragg gratings can be used for making all fiber demultiplexers. AWG Demultiplexer.osd (see Figure 1) shows an Array waveguide grating (AWG) demultiplexer. Figure 1 AWG Demultiplexer The OSA at the AWG output shows the selected WDM channel. For the first channel, the results are shown in Figure 2. Figure 2 AWG OSA Input The AWG…

Broadcast Star Coupler

Optical System - Figure 1 - Broadcast Star Couplers

The role of a star coupler is to combine the optical signals entering from its multiple input ports and divide it equally among its output ports. Broadcast Star Couplers.osd show a star coupler with 8 input ports; each port has a transmitter working in different wavelengths. Figure 1 – Broadcast Star Couplers The output of…

Optical Cross-Connects

Optical System - Figure 1 - Optical Cross-Connect

The development of wide-area WDM networks requires wavelength routing that can be reconfigure the network while maintaining its transparent nature. OXC Project.osd shows an optical cross connect with 2 input and 2 outputs, each port accommodate 4 wavelengths: Figure 1 –  Optical Cross-Connect

Configurable Optical Add-Drop Multiplexer

Optical System - Figure 1 - COADM layout

Designed to deliver increased functionality and flexibility necessary for today’s advanced optical networks, the COADM demonstrated in project COADM 4×4.osd enables up to 4 channels to be independently added and dropped at will. The system layout is presented in Figure 1; the input of the COADM is connected to a CW Laser Array, which generates…

Advanced Modulation Formats

Optical System - Figure 1 - Duobinary system layout

The objective of this lesson is to demonstrate the ability to modulate optical signals in formats different of the common RZ and NRZ. In this tutorial our goal is to generate a 40 Gb/s optical signal in the proposed modulation formats: duobinary modified-duobinary (MDRZ) Carrier-suppressed RZ (CSRZ), DPSK and DQPSK formats   To generate the…

Conventional Duobinary Transmitter

Optical System - Figure 1 - Optical duobinary system

Project ODB with Filters ModulationSystem.osd (Figure 1) demonstrates a system that is an optical duobinary system based on a conventional duobinary transmitter implemented by using a Mach-Zehnder modulator driven with three-level signals generated by using electrical low-pass filters. Figure 1 – Optical duobinary system

Modified Duobinary Transmitter

Optical System - Figure 1 - Modified duobinary system

Project MODB_ModulationSystem.osd (Figure 1) demonstrates a system that is an is optical modified duobinary RZ transmission system, which is equivalent to a duobinary carrier suppressed. Figure 1 – Modified duobinary system