Lightwave System Components

Optical System - Figure 1 Lightwave System Components

FOCS Introduction Lightwave System Components.osd details a generic block diagram of an optical communication system. An optical communication system consists of a: •transmitter •communication channel •receiver…

Optimizing Power and Dispersion Compensation for Nonlinear RZ Transmission

Optical System - Figure 2 Eye diagram for RZ modulation with optimum parameters

In this tutorial we show an example of a maximization procedure. We will optimize the launch power and DCF length to maximize the Q factor at the receiver. Upgrading an existing noise-limited fiber plant requires an increase in launched power, which in turn brings the fiber nonlinearities. It has been shown that nonlinear return to…

10 Gb/s Single Channel Transmission in Standard Mode Fibers (SMF)

Optical System - Figure 2 Comparison of RZ and NRZ transmission

The fundamental limitation to high-speed communication systems over the embedded standard single-mode fiber at 1.55 µm is the linear chromatic dispersion. Typical value of β2  = –20ps2 / km at 1.55 µm for SMF leads to D=16 ps/(nm.km). For bit rate B = 10 Gb/s, the slot duration is TB = 100 ps. If we…

40 Gb/s Single Channel Transmission in Standard Mode Fibers (SMF)

Optical System Figure 5 Transmission distance 500 km at 40 Gbs

The fundamental limitation to high- speed communication systems over the embedded standard single-mode fiber at 1.55 mm is the linear chromatic dispersion. Typical value of β2  = –20ps2/km at 1.55 µm for SMF leads to D=16 ps/(nm.km). For bit rate B = 40 Gb/s, the slot duration will be TB = 25 ps. If we…

Engineering the Fiber Nonlinearities and Dispersion

Optical System - Figure 1 Eye diagrams of the received signal for several received signal powers when system residual dispersion is a) 0, b) 800 psnm.

The purpose of this example is to investigate the fiber nonlinearity and dispersion related issues in a system.
As long as the optical power within an optical fiber is small, the fiber can be treated as linear medium. However, when the power level is high, we have to consider the impact of nonlinear effects.

System Design – Power Budget

Optical System - Figure 4 Power Budget

The purpose of power budget is to ensure that enough power will reach the receiver to maintain reliable performance during the entire system lifetime. The minimum average power required by the receiver is the receiver sensitivity. The average launch power is generally specified for each transmitter with optical powers expressed in dBm. In order to…

Time Division Multiplexing (TDM)

Optical System - Figure 8 OTDM 10 GBs - Receiver

In optical time-division multiplexing (OTDM) systems, several optical signal modulated at the bit rate B using the same carrier frequency are multiplexed optically to form a composite optical signal at a bit rate NB, where N is the number of multiplexed optical channels. OTDM Multiplexer.osd (see Figure 5) shows an OTDM transmitter.

Broadband Optical System Based on a Passive Optical Network (BPON)

Optical System - Figure 1 Broadband passive optical network

The system designed in project BPON Bidirectional.osd (Figure 1) provides a 622 Mbps of bidirectional access to multiple sites over a single fiber. It consists of an Optical Line Termination (OLT) at the service provider’s central office and 8 Optical Network Units (ONUs) near end users. Figure 1: Broadband passive optical network

Optical Code-Division Multiple-Access System (OCDMA)

Optical System - Figure 1 OCDMA system

The system designed in project SAC OCDMA.osd (Figure 1) is a spectral-amplitude-coding OCDMA. It has three users, where in this setup two users are transmitting data, while one user is off. The FBGs in the system are working as enconders/decoders for the incoherent optical signal.

Free Space Optics (FSO)

Optical System - Figure 1 FSO Link

Free Space Optics (FSO) communications [1] refers to the transmission of modulated visible or infrared beams through the atmosphere to obtain optical communications. FSO.osd (Figure 1) demonstrates a typical free space optical link operating at 1.25 GB/s, where usually the main source of penalty is the atmospheric attenuation.