Tag: fiber optic cable

Fiber optic cable has the ability to provide any business with safe, fast installations with higher bandwidth frequencies. In order to understand what fiber optic cable can do for your business or home, it’s important to understand the basic construction.

Fiber optic cables are design is consisted of: core, cladding, coating and jacket.Core- this is the very center of the cable and the light is guided down through by light transmission. The core is a single strand of glass that is measured in microns (µm). The larger the core, the more light the cable can carry.

Sizes of the core:

8μm (8.3 or 9μm) Single Mode

50μm – Mulit-mode

62.5μm – Multi-mode

Cladding- this is a thin layer of glass that surrounds the core and serves to contain the light within the core. The cladding has a different index of refraction than the core so the light waves that are re-directed back into the core allow for continuous light transmission within the fiber.

Size of the cladding:

125 µm.

Coating- This surrounds the cladding and acts as a protector for the glass. The coating is normally clear, but for all Outdoor cables the coating is color coded to help identify the individual fibers. This needs to be removed to connect the fiber to the connector or splice.

Size of coating:

250µm

Jacket- the cable jacket works along with the fibers to provide strength, signal integrity and overall protection of the fiber. There a variety of jacket materials that are used in the fiber cable construction. Environmental parameters that need to be considered upon installation are: temperature, chemical reaction, sunlight, mechanical and abrasion resistance.

If you would like to learn more about the benefit to fiber optic cable compared to copper cables, click this link to be transferred to another blog post to view more.

Fiber optic cable can be used for many applications such as: telecommunications, high bandwidth data, video signaling, long distance CCTV, communication between fire alarm panels and much more!

Although wire and cable are referred to as the same thing, they are different with separate characteristics. Both wire and cable are used in the communication and security world, and are designed to carry a message from one point to another. So what are the differences between the two?

Wire:

Wire is a single conductor with one or multiple strands of copper, they are low resistance and cost effective. A wire is the conductor that makes up a component of a cable. They are also measured by their diameter which is commonly referred to as gauge (AWG) size and insulated capacity. They are two types of wires: Solid and Stranded.

Solid wire: Single conductor that can be bare or insulated. This offers low resistance and are best used in higher frequency environments due to the design but are less flexible.

Stranded wire: Composed of numerous wires wrapped together to offer a larger conductor. This offers greater flexibility and higher resistance.

Cable:

A cable is a group of two or more insulated wires all wrapped into one jacket. Unlike wire, cable is designed with a “hot” wire carrying the current, neutral wire and a ground wire. They are classified by the number of wires it composed of and their gauge (AWG) sizes.

Twisted pair cable:

A twisted pair cable is designed with two cables that are twisted together. The twisting helps to eliminate noise which is why it is used to carry signals. Twisted pair cable comes both shielded and unshielded.

Coaxial cable:

A coaxial cable has a single conductor in the center and is surrounded by a braided metal shield. Inside the cable 2 conductors are separated by an insulating dielectric. These cables are harder to install but used for networking devices such as TVs or cameras.

Multi-Conductor cable:

A multi-conductor cable has two or more conductors inside of the jacket, they are insulated from each other, and can come in many variations. They are used to protect signal integrity by reducing noise and cross-talk.

Fiber Optic cable:

A fiber optic cable transmit signals through a bundle of glass threads. Fiber optic cable have a greater bandwidth than traditional copper cable so they are used for areas that receive high amounts of data. Click here to learn the different between copper vs fiber optic cable.

Fiber optic cables are used frequently for today’s telecommunication network because of their high bandwidth, high reliability and relatively low cost. To maximize the network performance, a good cable fiber management system must be in place. There are four fundamental principles for a good fiber cable management system:

1. Bend radius reduction

Fiber bends beyond the specified minimum bending radius can cause signal loss or even break the fiber, causing service disruption. Today, industry standards for traditional singlemode jumpers typically specify a minimum bend radius of ten times the outside diameter of the jacketed cable or 1.5″ (38 mm), whichever is greater. This new breed of flexible singlemode optical fiber has the potential to significantly reduce these minimum bend radius requirements to values as low as 0.6″ (15 mm), depending on the cable configuration, without increasing attenuation.

A reduced bend radius fiber is able to withstand tighter bends within frames, panels and pathways. It also enhances the reliability of a network and reduces network down time.

2. Well defined cable routing paths

The major reason of optical fiber cable minimum bend radius violation is improper routing of fibers by fiber installation technicians. Routing paths should be clearly pre-defined and easy to follow. In fact, these paths should be designed so that the technician has no other option than to route the cables properly. If an option is given to technician, inconsistent human decision could cause improper routing, and causes bend radius violation. Well defined routing paths can standardize fiber optic installation process, and less training time is required for fiber technicians.

Simplex OS1 9/125 Singlemode Fiber Optic Patch Cable

3. Easy access to installed optical fibers

Allowing easy access to installed fiber cable is essential for maintaining proper bend radius protection. The system should be designed to ensure that individual fibers can be installed or removed easily without negative effects on nearby fiber cable.

4. Physical protection of installed optical fibers

The management system must provide measures to physically protect fiber cables from accidental damage by technicians and equipments. Otherwise, the network reliability and performance will be adversely affected.

The National Security Agency most likely did not listen to you trudge to work this morning over a series of underground microphones. For all we know, the agency isn’t keeping its ears to the ground, as it were. But it could if it wanted to.

It would be the most ambitious use of what’s known as distributed acoustic sensing. Put simply, DAS systems exploit the very same fiber infrastructure that enables our day-to-day communications. But unlike the sensors and cameras baked into our phones and our computers, both tangible manifestations of the specter of surveillance, the largely untapped power (and potential abuse) of DAS is buried deep underground, virtually unseen. To think, a simple hardware add-on to existing fiber lines can have entire swaths of the telecom grid listening around the clock for anything considered physically out of the ordinary.

This is actually going on right now, albeit by a handful of private campanies specializing in both civilian and law enforcement applications of DAS technologies on land and at sea. So we should not get ahead of ourselves in presuming that Keith “I Don’t Know A Better Way to Do It” Alexander or any other NSA hacks have their ears to the ground. Indeed, of all that’s come to light from the ongoing NSA scandal, perhaps the most chilling revelation lies in the agency’s ability to eavesdrop on conversations by turning even your powered-down phone into a microphone. A sprawling network of NAS-DAS listening posts, with microphones positioned every ten meters along a fiber stretch, is probably still a pipe dream.

But the potential for an entity like the NSA to listen to you trudge to work over a series of underground mics is there. Everything is in place. Using DAS technology, the NSA might add a truly staggering number of listening devices to its global dragnet. The fiber optic cables criss-crossing the Earth, forming the central nervous system of telecommunications as we know them today, from email to texts to phone calls, are not simply the strings through which the NSA can listen to your conversations after flipping your powered-off phone into a microphone. The fiber optic cables criss-crossing the Earth are themselves a giant array of microphones, just laying in wait.

The components of fiber optic cables include the core, cladding, strength members, buffer, and jacket. Some types of cable also have a copper conductor that provides power to repeaters, concentrators, and other components.

The core of the cable is made of one or more glass or plastic fibers, and it provides the pathway through which the transmitted light can flow. Plastic is more flexible than glass; consequently, plastic is cheaper and easier to manufacture, but it doesn’t work very well over long distances. The diameter of a core will measure from two to several hundred microns. A micron is about 1/25,000 of an inch. For networking considerations you should use core sizes of 60 to 100 microns. Most networking cables have two core fibers, which allow the cables to transmit in both directions at once.

The core and cladding are manufactured as a single unit. The cladding is usually made from plastic, and it provides a refractive surface. Light that strikes this surface is reflected back into the core and continues its journey. The cladding has a lower refraction index, which means that it reflects light instead of absorbing light.

The buffer consists of one or more layers of plastic. It surrounds the cladding and core. The buffer strengthens the cable and prevents damage to the core.

The strength members are strands of very tough material, such as fiberglass, steel, or Kevlar. They provide extra strength for the cable.

The jacket (which can be either plenum or nonplenum) is the outer covering or shield of the cable.

Fiber-optic cable comes in two forms: single-mode and multi-mode. Single-mode cable is so narrow that light can travel through it only in a single path. This type of cable is extremely expensive and very difficult to work with. Multi-mode cable has a wider core diameter, which gives light beams the freedom to travel several paths. Unfortunately, this multi-path configuration allows for the possibility of signal distortion at the receiving end.

Fiber Optic Cable are used in applications where the optical signal is too strong and needs to be reduced. For example, in a multi-wavelength fiber optic system, you need to equalize the optical channel strength so that all the channels have similar power levels. This means to reduce stronger channels’ powers to match lower power channels.

The attenuation level is fixed at 5 dB, which means it reduces the optical power by 5dB. This attenuator has a short piece of fiber with metal ion doping that provides the specified attenuation.

There are many different mechanisms to reduce the optical power, this picture shows another mechanism used in one type of variable attenuator. Here variable means the attenuation level can be adjusted, for example, it could be from 1 dB up to 20dB.

Fiber Optic Cable are usually used in two scenarios.

The first case is in fiber optic power level testing. Cable are used to temporarily add a calibrated amount of signal loss in order to test the power level margins in a fiber optic communication system.

In the second case, Cable are permanently installed in a fiber optic communication link to properly match transmitter and receiver optical signal levels.

Optical Cable are typically classified as fixed or variable Cable.

Fixed Cable have a fixed optical power reduction number, such as 1dB, 5dB, 10dB, etc.

Variable Cable’ attenuation level can be adjusted, such as from 0.5 dB to 20dB, or even 50dB. Some variable Cable have very fine resolution, such as 0.1dB, or even 0.01dB.

This slide shows many different optical attenuator designs.

The female to female fixed Cable work like a regular adapter. But instead of minimizing insertion loss, it purposely adds some attenuation.

The female to female variable Cable are adjustable by turning a nut in the middle. The nut adjusts the air gap in the middle to achieve different attenuation levels.

The male to female fixed Cable work as fiber connectors, you can just plug in your existing fiber connector to its female side.

The in-line patch cable type variable Cable work as regular patch cables, but your can adjust its attenuation level by turning the screw.

For precise testing purposes, engineers have also designed instrument type variable Cable. These instrument type Cable have high attenuation ranges, such as from 0.5 dB to 70dB. They also have very fine resolution, such as 0.01dB. This is critical for accurate testing.