Fiber Optic Communication

Data security: Magnetic fields and current induction work in two ways, they just don’t generate noise in signal carrying conductors; they also let the information on the conductor to be leaked out. Since there are no radiated magnetic fields around optical fibers; electromagnetic fields are confined within the fiber. This makes it impossible to tap the signal being transmitted over fiber cable. Thus the fiber cable is the most secure medium available for carrying sensitive data.

Fiber: A fiber cable is either multiple strands of fiber optic surrounded by insulation, or a single fiber strand surrounded by insulation.

Fiber optic cable was once reserved for high-performance needs, but today it’s turning up in all kinds of networks. If you’re familiar with copper cable, you’ll quickly discover that fiber optic cable is a completely different animal. Not only is the installation process different for fiber, but also the troubleshooting process. Fiber optic cable is also far more fragile than copper cable, so there are more potential causes of trouble. I’ll discuss common fiber optic cable problems and how to diagnose and repair them. The most common causes of fiber optic malfunctionsAnyone who’s ever done network troubleshooting knows it’s a

Light source: it also known as illuminator. Usually it is situated at the base of the microscope. Used to provide light to the sample in order to facilitate the experiment.

n.d. Web. 20 Nov. 2015. , it gives the definition of different parts of a compound light

Figure 1. Confocal fluorescence images of unstained fibers showing numerous autofluorescent inclusions in the core of two fibers. Bar: 50 μm, (Feeney et al., 2014)

Bending loss of the fiber α=0.0092dB/loop, the equivalent step index fiber cladding refractive index n_e=1.4444, bending loss of it α_e=0.0829dB/loop.

This paper demonstrates a fiber optic communications link for aircraft that utilizes wavelength division multiplexing (WDM) to avionics environment to support multiple analog RF signals transmission simultaneous over single optical fiber. This paper investigates the simultaneous transmission of two RF signals over a single optical fiber. The transmission of FM and AM analog modulated signals, and also FSK digital modulated signals, over a fiber optic link (FOL) employing wavelength division multiplexing is determined. We present data from measurements of power loss, total harmonic distortion (THD), signal-to-noise ratio (SNR), delay, carrier-to-noise ratio (CNR), and bit error rate (BER).The results indicate that wavelength division multiplexing is a fiber optic technology appropriate for avionics applications.

The high-speed broadband penetration and ongoing growth of the Internet traffic among customers have been the key reasons that are driving the rapid emergence and deployment of optical access networks as a basic bearer network that supports hybrids services for multiple customers while bearing huge capacity. Passive optical network is the most interesting solution for the optical access network to cope with the increasing bandwidth demand and to meet the cost effectiveness. PON can be used for Point to point (P2P) or Point to multi-point (P2MP) configurations. The P2P structure builds a dedicated fiber from a CO to each subscriber which constitutes an ultimate solution to provide much-needed bandwidth to each ONU. In P2MP topologies, the feeder fiber is shared between various customers and terminates at a central office in an Optical Line Terminal. Passive splitters put between the OLT and the ONU are used to split the connection to multiple end points, thus enormously reduces the maintaining cost. Two key technologies are used in passive optical network: the first one known as TDM-PON uses Time Division Multiplexing to multiplex traffic from/to multiple ONUs onto the upstream/downstream wavelength. It requires complex scheduling algorithms and framing technology to support a variety of services. The second is Wavelength division multiplexing passive optical network “WDM PON”. This technology comes to extend the

Large, monolithic satellites are slowly being overtaken by Distributed Space Systems (DSS) comprised of a network or networks of multiple inexpensive, small, smart satellites. Thus, necessitating the need for intersatellite communications. This trend is primarily prompted by cost and the commercialization of space. An ancillary by-product of this trend is the push towards the use of Commercial Off-the-Shelf (COTS) Plus (aka.: upscreened) parts. Foregoing space-rated parts has been made possible as a result of the standardization and accreditation of the terrestrial fiber optics industry.

On the Contrary, a properly designed high-index single-ring fiber can support only the radially fundamental modes. It leads to the potential Reduction of the crosstalk induced during mode excitement. To multiplex multiple OAM modes simultaneously, the number of the Eigen modes supported by the fiber should be increased by increasing either the core radius or the refractive index difference between the core and cladding. In this Theory, one dimensional mode

Today, SCC are made up of pure glass fibers that allow light to transmit using internal reflection. These optical fibers are

The hybrid Fiber-Wireless networks are the combination of both optical back-end and wireless front-end. The commercial deployment of FiWi access networks faces a number of challenges including network deployment [5-7], network routing [8-12], frame aggregation [13],[14] and bandwidth allocation. The main focus of this paper is on the bandwidth allocation process where network resources are shared between the users on the same network. This process manages the distribution of available bandwidth in terms of Bytes, timeslots, channels, sub channels and subcarriers to the users. Bandwidth allocation algorithms could be static/fixed or dynamic bandwidth allocation algorithms (DBA). The static algorithms distribute bandwidth equally between users in the same network. These algorithms suffer from inefficient utilization of bandwidth thus degrading the network performance. Therefore, researches on DBA algorithms have gained many researchers attention in FiWi networks.

OFDM is a great technique to handle impairments of wireless communication channels such as multipath propagation. Hence, OFDM is a practical candidate for future 4G wireless communications techniques [1]-[4]. On the other hand, one of the major drawbacks of the OFDM communication system is the drift in reference carrier. The offset present in received carrier will lose orthogonality among the carriers. Hence, the CFO causes a reduction of desired signal amplitude in the output decision variable and introduces ICI. Then it brings up an increase of BER. The effect caused by CFO for OFDM system was analyzed in [7]-[9]. In [7] BER upper bound of OFDM system is analyzed without ICI self-cancellation and BER of OFDM system is analyzed using self-cancellation, but this method is less accurate. In [9], it is indicated that CFO should be less than 2% of the bandwidth of the sub-channel to guarantee the signal to interference ratio to be higher than 30 dB. A critically sampled OFDM system/OQAM system is also not robust to CFO [9], even when optimal pulses are used as shaping filters. Thus, carrier frequency offset greatly degrades system performance. Therefore, practical OFDM systems need the CFO to be compensated with sufficient accuracy, and this has led to a whole lot of literature on CFO estimation algorithms. Most of the existing CFO estimators for OFDM are based on periodically transmitted pilot symbols. Yet, the pilot symbols transmission loses a significant bandwidth,

Light enters one end of the fiber from a light bulb, laser, or some other source, and travels essentially unimpeded all the way to the length of the fiber where it is intercepted by a photosensitive detector such as an electronic device or even the human eye. The distance of travel varies according to the use to anywhere from just a few inches to over one-hundred and fifty miles. Fiber optic cable can transmit large amounts of information over one-hundred and fifty miles almost instantaneously. “While it takes five hours to transmit the contents of an encyclopedia over copper wires, the entire work can be transmitted in less than a minute over fiber optics” (Yawn PG).