Single Mode Fiber Type: G652 vs G655 Fiber

With the increasing demand for greater capacity over long distance transmission, single mode fiber optic cable is designed with various versions. There are 6 different categories of SMFs: G652, G653, G654, G655, G656 and G657, among which G652 and G655 are two options frequently used in WDM. So G652 vs G655 fiber: what’s the difference?

Single Mode Fiber: What Is G652?

G652 is currently the most popularly adopted single mode fiber, for which G652 is defined as Standard SMF. It has G652A, B, C and D four versions. G652A and B have a zero dispersion wavelength point at 1310 nm, which makes it a natural fit for operation in the 1310 nm band. However, they are not suitable for applications in Wavelength Division Multiplexing (WDM) due to water peak. The more advanced C and D are optimized with elimination of water peak for spectrum operation, which makes them effective at wavelength between 1310 to 1550 nm to support Coarse Wavelength Division Multiplexing (CWDM). Comparing G652C, G652D single mode fiber has superior PDM (polarization mode dispersion) parameter, for which G652D is known as Standard single mode fiber (SSMF) and commonly used to support 10GbE and 40GbE system. FS. COM provides such G652D LC fiber in various versions.

FS.COM G652D LC single mode fiber single mode fiber

Figure 1: This photo shows a FS.COM G652D LC single mode fiber.

Single Mode Fiber: What Is G655?

G655 is known as nonzero dispersion-shifted fiber (NZDSF), because the dispersion at the wavelength of 1550 nm is close to zero but not zero. It is further divided into A, B and C three subcategories. There are two types of NZDSF: (+D)NZDSF and (-D)NZDSF, the dispersion of which is respectively proportional and inversely proportional to wavelength. Among them, the positive dispersion of G655 overcomes nonlinear effects in WDM system such as four wave mixing (FWM) due to high effective area. G655 is specified at 1550 nm and 1620 nm, and has low value of chromatic dispersion in the c-band (1530 -1660 nm), in which Erbium Doped Fiber Amplifier (EDFA) boost the optical signals. This match gives G655 an edge over G652. G655 fiber is suitable for DWDM system to meet increasing transmission capacity and long haul high capacity WDM transmission system.

Difference of G652 vs G655 single mode fiber

Figure 2: This diagram shows the difference of G652 vs G655.

G652 vs G655 Single Mode Fiber: What’s the Difference?

Table below shows the detail information of G652 vs G655 fiber.

Fiber Type G652 G655
Alternative Name Standard SMF/zero dispersion-shifted fiber (non dispersion-shifted fiber) Nonzero dispersion-shifted fiber (NZDSF)
Specified Wavelength 1310, 1550, 1625 nm (C and D excluded) 1550-1625 nm
Dispersion Point 1310 nm 1550 nm
Dispersion Value Higher Low
Attenuation Parameter Less than 0.4 dB/km Typically 0.2 dB/km at 1550 nm
PMD Parameter Less than 0.5 over C and 0.2 over D Less than 0.1 ps/sqrt (km)
Applications LAN, MAN, access networks and CWDM transmission Long-haul systems that use DWDM transmission
Price Lower than G655 High
Features Reduced water peak Low dispersion value; overcoming nonlinear effect

As shown in the table, G652 and G655 fiber are two single mode fiber types defined with different specifications of wavelength, dispersion, parameter of attenuation and PMD. G652 is featured a zero dispersion wavelength at 1310 and reduced water peak to support CWDM. G655 is an enhanced single mode fiber with the characteristic of elimination of FWM and low dispersion value, typically applied to long and high-speed DWDM transmission. For consideration of both the function and price, G652 especially G652D version has become the most commonly used one.

Conclusion

This article introduced two categories of single mode fiber types and made a contrast between G652 vs G655. It’s not proper to say one type beats the other since both have their characteristics for different applications. For transmission not requiring very high rate and long distance, G652. D can be the choice. But for much higher capacity and long distance required DWDM system, G655 will best meet the needs regardless of much higher cost.

Comparing Three Fiber Optic Cable Manufacturers—Monoprice, C2G & FS.COM

To meet surging market needs for fiber optic cable product, more and more fiber optic cable manufacturers emerges to gain its market share. Fiber optic cable is a necessity for most households. How to keep a balance between price and quality? And how to select a reliable fiber optic cable manufacturer? As the representatives of reputable fiber optic cable manufacturers, Monoprice, C2G and FS.COM are frequently recommended by many users. This article would give a brief introduction to those three companies and analyze the difference between their fiber optic cable.

fiber-patch-cords

Monoprice—The Meek King of Cables

Five years ago, Monoprice was associated with two things: HDMI cables and nerds. Being able to tell people about two-buck Monoprice cables, and to explain, with confidence, why Monster cables were a scam, was one of the wonderful small privileges of geekdom; today, it’s one of the dwindling few. Its cables were cheap! They worked fine! The company was based in the U.S., processed orders quickly, had a return policy and answered emails. It was like eBay without the risk.

Founded in 2002 and propelled by word-of-mouth support — the company rarely advertises — Monoprice is now a $120m-a-year business. Monoprice CEO Ajay Kumar says the company has been growing at between 25% and 35% a year for the last five years. The office and shipping operations run out of a 173,000 square-foot warehouse in Rancho Cucamonga, California. Kumar credits Monoprice’s early rise to one thing. “The primary focus early on was cables,” he says, “and the thing that really accelerated the company was HDMI.” For the fiber optic cables, they offer a wide range of them, singlemode, multimode and etc.

C2G—A Trustful Cable Vendor

C2G (formerly Cables To Go), a division of Lastar, Inc., is an industry leader in high performance cabling and connectivity solutions. Founded in 1984, the company provides end-to-end connectivity solutions serving a variety of markets—including hospitality, education, healthcare, corporate, home theater and digital signage. C2G also delivers customized connectivity products and solutions renowned for superior quality, value, and innovation using premium components and the latest technologies to maximize cable performance and ensure compliance with industry specifications for each cable and its designated application. Fiber optic cabling and hardware products including single mode and multimode fiber patch cables of 62.5/125, 50/125, and 9/125, and fiber distribution products used in high tech networking.

FS.COM—A Cost-effective Fiber Optic Cable Manufacturer

Founded in 2009, FS.COM gradually becomes a leading company devoting to research & development, and offer fiber connectivity network solutions for carriers, ISPs, content providers and networks. With a few years of development and accumulation, FS.COM have owned a whole series of optical communication products including the WDM equipment, transceivers, fiber optic assemblies, racks & enclosures, bulk fiber cables, enterprise network and so on.

Their wholesale fiber optic cable products are offered at the lowest price and fully compatible with the original devices. They assured to every customers that every fiber optic cable offered by FS.COM before shipping has to go through strict test to assure high performance. They cover a wide range of fiber optic cables, such as bulk fiber cables, fiber patch cables, MTP/MPO fiber cable, fiber cable assemblies and etc.

Fiber Optic Cable Manufacturers—Monoprice Vs. C2G Vs. FS.COM

—Fiber Optic Cable Price

Price is paramount for every customers when they are purchasing. We can’t list all the products from their website and compare them here. So let’s take the 1m OS2 9/125 singlemode fiber optic cable as an example, the C2G 1m OS2 9/125 singlemode fiber optic cable is sold at $42.99. Monoprice is only $11.35. The price of 1m OS2 9/125 singlemode fiber optic cable from FS.COM is $2.8. You can check it on the below table.

Comparing Three Fiber Optic Cable Manufacturers Table

—Products Options

Both FS.COM and C2G offer a full range of fiber optic cable that are of performance. While monoprice, nowadays do not have many selections of optical modules. But if you need HDMI, video or power cables, you can definitely have a look at their website.

—Reputation

FS.COM is known as the cost-effective optical transceiver and fiber optic cable manufacturer that offer high-quality and low price products. Monoprice is mostly recommended for its HDMI, video and power cables. C2G’s price is a little bit higher, but their quality is nice.

How to Select Fiber Optic Cables of High Quality?

With the growing numbers of fiber optic patch cord manufacturers, it is difficult to distinguish the quality of fiber optic cables. Poor fiber jumpers could result in many adverse consequences, such as data loss, signal delay and etc. When selecting fiber optic cables, you should pay much attention to the trap of the low price so as to avoid picking up production made by recovered materials. In this article, we would introduce some detailed process to guide you to make right decision for selecting decent fiber optic cables.

About Fiber Optic Cable

Fiber optic cable, also called fiber optic jumper or fiber optic patch cord, is a length of fiber cabling fitted with LC, SC, FC, E2000, DIN, MTRJ or ST connectors at each end. Ferrule is paramount to fiber, which is a ring or cap attached to an object to protect against damage, splitting, or wear. As an essential component in fiber optic, it is used to align and protect the stripped end of a fiber.

fiber optic cable

Manufacturing Process of Fiber Optic Cable

Place of origin attaches great importance to any products, so does the fiber optic cable. Besides the origin, method of manufacture also matters. The production process of fiber optic patch codes is very complicated unless you master it very well. Following is the production process of fiber optic patch cords.

Step1: Pretreatment of fiber optic. Peel fibers by using technical instrument, the main propose of it is to peel the fiber jacket.

Step2: Installment of Fiber ferrule. Fiber ferrule is an important part of fiber optic patch cables, so when installing fiber ferrule, the quality of it should be concerned.

Step3: Preparation of grouting glue.Get the glue ready since fiber stub need to be grouted later. Gel injection of fiber ferrule. The standard of a good gel injection is that a little glue can be seen at the front end of fiber ferrule.

Step4: Solidification of colloid. Insert the fiber into fiber ferrule which has been injected gel, and then put it in curing oven to be solidified. Usually, the temperature of solidification is 80 to 90 degree.

As being mentioned, fiber ferrule is a vital part in fiber optic cable, which is used together with the connector that connects the fiber cable either to another cable or to a transmitter or receiver. The ferrule keeps the fibers accurately aligned within the connector. And thus, the quality of fiber jumpers depends on the quality of fiber ferrule in a large extent. However, in order to achieve more benefits, many manufacturers buy in inferior fiber ferrule or reuse fiber ferrule. As a result, the fiber optic patch cables they made are of poor quality. So it is not a good way to buy cheap jumpers without putting the fiber optic patch cord manufacturers into consideration.

LC-patch-cords

Conclusion

So how to choose a decent fiber optic patch cord manufacturer? Here are some indispensable and refined characteristics of reliable fiber optic cable suppliers: have a good sense of service, treat customers as friends, provide reasonable price but not the cheapest, have a sense of service, and also conscientious, instead of those sell their products randomly just concerning about their performance and benefits.

A Brief Overview of Fiber Optic Cable

Introduction

A fiber optic cable, also known as optical fiber cable, is a network cable that contains two or more glass or plastic fiber cores located within a protective coating and covered with a plastic PVC outer sleeve. It’s correlated with transmission of information as light pulses along a glass or plastic strand or fiber. It’s designed for long distance, very high performance data networking and telecommunications. It has many advantages in optical fiber communication, such as large capacity, long relay distance, good security, free from electromagnetic interference and copper saving.

fiber- optic- cable

Types of Fiber Optic Cables

According to the transmission mode of light in optical fiber, fiber optic cable can be divided into single-mode fiber (SMF) and multimode fiber (MMF). Although they all belong to optical cables and aim at transmitting information, they still have some slight differences.

SMF & MMF

Single-Mode Fiber

Literally, Single-mode fiber is a single stand of glass fiber with a diameter of 8.3 to 10 microns that has one mode of transmission. Due to its smaller diameter, single-mode fiber is used for long-distance signal transmission, which minimizes the reduction in signal strength. Single-mode fiber also has a considerably higher bandwidth than multimode fiber. The light source used for single-mode fiber is typically a laser, which makes it more expensive than multimode fiber.

Multimode Fiber

By comparison, multimode fiber cable, with a diameter of about 62.5 microns, allows multiple mode of light to propagate through it simultaneously, thus forming mode dispersion. Mode dispersion technology limits the bandwidth and distance of multimode fiber. Therefore, multimode fiber features larger core diameter and short transmission distance. Multimode fiber typically uses an LED to create the light pulse, which makes it cheaper than single-mode fiber.

Both single-mode and multimode fiber can handle 10G speeds. The most evident difference between them lies in the distance. Within a data center, it’s typical to use multimode fiber which can get you 300-400 meters. If you have very long runs or are connecting over longer distance, single-mode fiber can get you 10 km, 40 km, 80 km, or even farther. You just need to use the appropriate optic for the distance required.

Fiber Cable Uses

It’s widely acknowledged that optical cables are usually applied into computer networking and telecommunication due to its ability to transmit data and information. What’s more, it’s also used by military and space industries as means of communication and signal transfer, in addition to its ability to provide temperature sensing. In recent years, fiber cable is frequently used in a variety of medical instruments to provide precise illumination. An endoscope, for example, is a flexible tube containing several optical cables. When it slips into the patient’s mouth, nose, digestive tract, and other heart areas that are not visible outside the body, the doctor can see the changes through the endoscope. Other medical applications for fiber optics include X-ray imaging, biomedical sensors, light therapy and surgical microscopy.

Conclusion

From the aforementioned article, we can see that fiber optic cables have different types with different features, and are widely used in telecommunication, military, medical applications, etc. If you would like to know more or would like assistance in choosing the appropriate optical fiber cable, welcome to visit our website www.fs.com for more detailed information. FS will provide more choices and better services for our clients.

Special Fiber Patch Cable for Mode Conditioning

As we all know, standard fiber patch cables can be divided into the single-mode type and multimode type. Data communication is more stable between fiber patch cables with the same mode. When single-mode and multimode cables are directly linked together, an effect named as differential mode delay (DMD) often occurs. It is a variation in propagation delay because of the differences in group velocity among modes of an optical fiber. Under the influence of DMD, cable distance is greatly limited and network bandwidth is also reduced over the distance. However, using the single-mode cables with multimode cables is sometimes necessary for certain applications. Is there any solution to this problem? Of course, this is why mode conditioning patch cable is made for.

Overview of Mode Conditioning Patch Cable

Mode conditioning patch cable is always designed to be the duplex style. It contains a conditioned channel with an offset fiber connection part. The connectors on both ends are also optional from LC, SC, ST and other types. In general, mode conditioning patch cable is needed when link distances are over 300 meters. Although mode conditioning patch cable looks different from the standard fiber patch cable, they both function for the same performance.

mode conditioning patch cable

Working Principle of Mode Conditioning Cable

Cable offset is the core of mode conditioning patch cable. A multimode fiber and a single-mode fiber are fusion spliced together with a precise core alignment and angle inside the offset. Optical light is launched from the single-mode fiber to the multimode fiber at a precise angle, which provides the cable with mode conditioning functionality. In this way, optical signal is able to freely pass different fiber modes without the problem of DMD.

cable offset

Features & Benefits of Mode Conditioning Cable
Features
  • IEEE-802.3z (Gigabit Ethernet) Compliant
  • Permanent offset closure
  • Low profile offset closure
  • Low insertion loss
  • Fits existing cabling scheme
  • Easy to use
  • Reduced modal noise
  • OFNR rated jacket complies with strict building codes
Benefits
  • Eliminate DMD effect
  • Correct offset always maintained
  • Aesthetically pleasing
  • Uses precision ceramic ferrules
  • Use in place of standard equipment-to-cable plant patch cord
  • Functions the same as a standard patch cord
Applications of Mode Conditioning Patch Cable

Mode conditioning patch cable is suitable for 1000BASE-LX long wave applications of Gigabit Ethernet, such as 1000BASE-LX routers, switches, or transceivers. This is because 1000BASE-LX should operate for both single-mode and multimode cables. A mode conditioning patch cable eliminates the multiple signals by allowing the single-mode launch to be offset away from the center of a multimode fiber.

When the Gigabit LX switch is equipped with SC or LC connectors, the yellow leg (single-mode) of the cable should be connected to the transmit side, and the orange leg (OM2 multimode) of the cable should be connected to the receive side. Both ends must maintain this configuration. Exchanging the transmit and receive is only allowed at the cable plant side.

application of mode conditioning patch cable

In addition, mode conditioning patch cords can only convert optical signals from single-mode to multimode. If you want to convert from multimode to single-mode, you’d better use a media converter.

Conclusion

Mode conditioning cable is a special fiber patch cable designed for reducing the differential mode delay between single-mode and multimode data transmission. This type of cable is usually used in pairs. Different connectors types, cable jackets, fiber types, cable lengths are also available to meet your demands. This post provides some basic knowledge about mode conditioning cable. If you are interested, please visit FS.COM for more information.

Using IP67 Fiber Cable For Fiber Link Protection

Fiber optic cables have taken a large percentage of today’s network market. Compared with copper cables, optical cables are faster in speed and lighter for carry. The deployment of fiber optic cables has brought many benefits to ordinary people, but the disadvantages of fibers can also be fatal. Optic fibers are easily breakable and polluted by dust, liquid and other contamination. Hence, fiber optic cables should be designed to accommodate to different kinds of environment. IP67 fiber cable is a type of specially used fiber cable with dust-proof and water-proof functions. This post will guide you to know more about this special fiber cable.

Meaning of IP67

When hearing the name of IP67 fiber cable, you may be curious about the meaning of IP67. Actually, “IP” is a kind of rating defined by International Standard IEC 60529. The abbreviation stands for international protection which classifies the degrees of protection provided against the intrusion of solid object (including body parts), dust, accidental contact, and water in electrical enclosures. The IP code consists of two numbers, such as IP67. The first number represents the solid object protection, and the second is the water protection. Following picture presents the category of IP codes. If either number is represented by an “X”, it means the product has not been tested in that category. It does not equate to a ranking of 0, but it also does not guarantee any protection. Therefore, IP67 means that the cable is protected from dust at the highest level and against temporary immersion in water.

ip-rating-code

Construction of IP67 Fiber Cable

IP67 fiber optic patch cable contains the ordinary optic fiber and special IP67 fiber optic connector. IP67 connector is designed based on the conventional connector with a aluminum shell of spring-loaded push-pull locking mechanism. The shell protection can block dust and liquid from the inside connector. The following picture gives a detailed structure of IP67 LC duplex connector.

structure-of-ip76-cable-connector

Types of IP67 Cables

According to the connectors on each ends, IP67 fiber optic cables can be divided into two types. One type is equipped with IP67 connectors on both ends, and another type is terminated with a IP67 connector on one end and common fiber optic connectors on the other end. Fanout IP67 fiber optic cable is also used for high-density connections.

ip67-fiber-cable

Applications

The strong PU jacket and single-mode APC armored structure of IP67 cable provides 1 Gbps data transfer speed in high bandwidth application, which is five times quicker than standard 9/125 μm fiber patch cable. The low insertion loss IP67 cable connector has a simple push-to-latch and a pull-to-release outer sleeve for mating and un-mating action allowing for easier install or uninstall. Designed according to the IEC60603-7 interface standard, the connector can also match with other similar mechanical systems. IP67 cables are often used in FTTH, FTTA, LAN test equipment and military industry deployed at junction cabinets in the street, remote radio head connection, wind mills or direct buried installation.

Conclusion

IP67 fiber optic cable offers great protection for optic fibers against dust and water under severe outer environment. It is wise to use IP67 fiber cables in these places to secure your data links. Inner shell connectors of the cable are now optional with LC, SC, ST and FC types. You may regard IP67 cable as a considerable choice for your network.

In-depth Understanding of Fiber Optic Cables

The commitment to fiber optic technology has spanned more than 30 years, and nowadays a high level of glass purity, fiber optic cable, has been achieved owing to the continuous research and development. This purity, combined with improved system electronics, enables to transmit digitized light signals over hundreds of kilometers with high performance, offering many advantages in fiber optic systems. This text provides an overview of the construction, categories, and working principles of this fiber optic cable.

Construction of Fiber Optic Cable

Fiber optic cable generally consists of fiver elements : the optic core, optic cladding, a buffer material, a strength material and the outer jacket. Here, much more detailed information is attributive to the optic core and optic cladding which are both made from doped silica (glass).

The Optic Core and Cladding Details

The optic core is the light-carrying element at the center of the cable, and the optic cladding surrounds the optic core. Their combination makes the principle of total internal reflection possible. Besides, a protective acrylate coating then surrounds the cladding. In most cases, the protective coating is a dual layer composition: a soft inner layer that cushions the fiber and allows the coating to be stripped from the glass mechanically, and a harder outer layer that protects the fiber during handling, particularly the cabling, installation, and termination processes. This coating protects the glass from dust and scratches that can affect fiber strength.

Optic Core and Cladding, makes reflection possible

Categories of Fiber Optic Cable

There are two general categories of fiber optic cable: single-mode fiber (SMF) and multi-mode fiber (MMF).

MMF was the first type of fiber to be commercialized. It has a core of 50 to 62.5 µm in diameter much larger than SMF, allowing hundreds of modes of light to propagate through the fiber simultaneously. Additionally, the larger core diameter of MMF facilitates the use of lower-cost optical transmitters (such as light emitting diodes or vertical cavity surface emitting lasers) and connectors, more suitable for relatively shorter-reach application. Take 1 Gigabit Ethernet (GbE) applications for example, MMF is deployed to establish 550m link length with 1000BASE-SX SFPs (eg. Cisco Meraki MA-SFP-1GB-SX).

SMF, in contrast, has a much smaller core, approximately 8 to 10 µm in diameter, which allows only one mode of light at a time to propagate through the core. It’s designed to maintain spatial and spectral integrity of each optical signal over longer distances, permitting more information to be transmitted. Similarly, as for 1GbE applications, SMF is able to realize 70km reach with 1000BASE-ZX SFPs, like GLC-ZX-SM, a product compatible with Cisco listed in Fiberstore.

GLC-ZX-SM, 1000BASE-ZX SFP

Working Principles of Fiber Optic Cable

The operation of a fiber optic cable is based on the principle of total internal reflection. Light reflects (bounces back) or refracts (alters its direction while penetrating a different medium), depending on the angle at which it strikes a surface.

This principle comes at the center of how fiber optic cable works. Controlling the angle at which the lightwaves are transmitted makes it possible to control how efficiently they reach their destination. Lightwaves are guided through the core of the fiber optic cable in much the same way that radio frequency (RF) signals are guided through coaxial cable. The lightwaves are guided to the other end of the fiber being reflected within the core. The composition of the cladding glass related to the core glass determines the fiber’s ability to reflect light. That reflection is usually caused by creating a higher refractive index in the core of the glass instead of in the surrounding cladding glass, creating a waveguide. The refractive index of the core is increased by slightly modifying the composition of the core glass, generally by adding small amounts of a dopant. Alternatively, the waveguide can be created by reducing the refractive index of the cladding using different dopants.

Conclusion

In fiber optic cables, the light can carry more information over longer distances than the amount carried in a copper or coaxial medium or radio frequencies through a wireless medium. With few transmission losses, low interference, and high bandwidth, fiber optic cables are the ideal transmission medium. Fiberstore offers various kinds of fiber optic cables, including SMF and MMF types, simplex and duplex fiber optic cables, indoor distribution cables and outdoor loose tube cables, etc. For more information about fiber optic cables, you can visit Fiberstore.

Guide to Coaxial Cable, Twisted Pair Cable and Fiber Optic Cable

The advancements of cable-based technologies have made wider accessibility to greater bandwidth possible in Local Area Network (LAN). With so many network options, to select a right cable-based solution for broadband connection services is a little confusing. When such factors as cost, speed, bandwidth and immunity are considered, which one is an ideal choice for networks, coaxial cable or twisted pair cable? Or is the fiber optic cable that meets your needs?

Coaxial Cable

Coaxial cable, or  in a foam insulation, symmetrically surrounded by a woven braided metal shield, then covered in a plastic jacket. Because of its insulating property, coaxial cable can carry analogy signals with a wide range of frequencies. Thus it is widely used in feedlines connecting radio transmitters and receivers with their antennas, computer network connections, digital audio, and distributing cable television signals. The following figure shows the structure of coaxial cable.

Coaxial cable, a single wire usually copper wrapped

Actually, there exists another cable, twin-ax cable, which is similar to coaxial cable, but with two inner conductors instead of one. This kind of cable comes in either an active or passive twin-ax (twin-axial) cable assembly, used for 10, 40 or 100 Gigabit Ethernet (GbE) links.Like QSFP-H40G-CU1M, this Cisco 40G cabling product is the QSFP to QSFP passive copper cable assembly designed for high-performance 40GbE networks.

QSFP-H40G-CU1M, QSFP to QSFP passive copper cable assembly

Twisted Pair Cable

Twisted pair cable is a type of wiring in which two conductors of a single circuit are twisted together. It comes in two versions: Shielded Twisted Pair (STP) and Unshielded Twisted Pair (UTP). STP is commonly used in Token Ring networks and UTP is in Ethernet networks. The image below displays what UTP (left) and STP (right) look like.

Twisted pair cable, UTP and STP

Fiber Optic Cable

A fiber optic cable is a cable containing one or more optical fibers. Fiber optic cables often contain several silica cores, and each fiber can accommodate many wavelengths (or channels), allowing fiber to accommodate ever-increasing data capacity requirements. When terminated with LC/SC/ST/FC/MTRJ/MU/SMA connectors on both ends, such as LC-LC, LC-SC, LC-ST, SC-ST, SC-SC, ST-ST etc, fiber optic cables can achieve fiber link connection between equipment.

Comparison of Three Kinds of Cables

Coaxial cable can be installed easily, relatively resistant to interference. However, it is bulky and just ideal for short length because of its high attenuation. It would be expensive over long-distance data transmission. By contrast, twisted pair cable is the most flexible and cheapest among three kinds of cables, easy to install and operate. But it also encounters attenuation problem and offers relatively low bandwidth. In addition, it is susceptible to interference and noises. As one of the most popular mediums for both new cabling installations and upgrades, including backbone, horizontal, and even desktop applications, fiber optic cable is small in size and light in weight. Because the conductor is glass which means that no electricity can flow through, fiber cable is immune to electromagnetic interference. The biggest advantage of fiber optic cable is that it can transmit a big amount of data with low loss at high speed over long distance. Nevertheless, it needs complicated installing skills, difficult to work with and expensive in the short run.

When selecting which kind of cable is appropriate for network services, one should keep in mind that each cable has its unique advantages and disadvantages concerning about these factors: cost, speed, security, reliability, bandwidth, data carrying-capacity, and so on.

Conclusion

Choosing among coaxial cable, twin-ax cable, twisted pair cable and fiber optic cable depends on your needs. You can balance the cost and the requirements of bandwidth to make a choice. In Fiberstore, you can find twisted pair cables and a series of fiber optic cables. Other cables, such as active optical cable (AOC) (eg. QSFP-4X10G-AOC10M) are also available for your networks. You can visit Fiberstore for more information about cable-based solutions.

Fiber Optic Cable and Connector Selection

Proper selection of fiber optic cables and connectors for specific uses is becoming more and more important as fiber optic systems become the transmission medium for communications and aircraft applications, and even antenna links. Choices must be made in selecting fiber optic cables and connectors for high-reliability applications. This article provides the knowledge for how to make appropriate selections of fiber optic cable and connector when designing a fiber optic system.

Fiber Optic Cable Selection

To select a fiber optic cable, you have to make choices of both the fiber selection and the cable construction selection.

Fiber Selection

The three major fiber parameters used in selecting the proper fiber for an application are bandwidth, attenuation and core diameter.

Bandwidth: The bandwidth at a specified wavelength represents the highest sinusoidal light modulation frequency that can be transmitted through a length of fiber with an optical signal power loss equal to 50 percent of the zero modulation frequency component. The bandwidth is expressed in megahertz over a kilometer length (MHz/km).

Attenuation: The optical attenuation denotes the amount of optical power lost due to absorption and scattering of optical radiation at a specified wavelength in a length of fiber. It is expressed as an attenuation in decibels of optical power per kilometer (dB/km). The attenuation is determined by launching a narrow spectral band of light into the full length of fiber and measuring the transmitted intensity.

Core Diameter: The fiber core is the central region of an optical fiber whose refractive index is higher than that of the fiber cladding. Various core diameters are available to permit the most efficient coupling of light from commercially available light sources, such as laser diodes. There are two basic fiber types, single-mode and multimode. Single-mode fiber has a core diameter of 8 to 10 microns and is normally used for long distance requirements and high-bandwidth applications. Multimode fiber has a core diameter of 50 or 62.5 microns and is usually used in buildings. The picture below shows single-mode and multimode fiber with different core diameters.

multimode and singlemode fiber

Cable Construction Selection

Another important consideration when specifying optical fiber cable is the cable construction. There are three main types of cable configurations: buffered fiber cable, simplex cable and multichannel cable.

Buffered Fiber Cable: There are two kinds of buffered fiber. The first is a loose buffer tube construction where the fiber is contained in a water-blocked polymer tube that has an inner diameter considerably larger than the fiber itself. The loose buffer tube construction offers lower cable attenuation from a given fiber, and a high level of isolation from external forces. Loose buffer cables are typically used in outdoor applications and can accommodate the changes in external conditions. The second is a tight buffer tube design. A thick buffer coating is placed directly on the fiber. The tight buffer construction permits smaller, lighter weight designs and generally yields a more flexible cable. A comparison of these two cable constructions is shown below.

Buffered Fiber

Simplex Cable: A simplex fiber optic cable has only one tight buffered optical fiber inside the cable jackets. Simplex fiber optic cables are typically categorized as interconnect cables and are used to make interconnections in front of the patch panel. They are designed for production termination where consistency and uniformity are vital for fast and efficient operation.

Multichannel Cable: Building multiple fibers into one cable creates a multichannel cable. This type of cable is usually built with either a central or external strength member and fiber bundled around or within the strength member. An external jacket is used to keep the cable together.

Fiber Optic Connector Selection

Connector is an integral component of the cabling system infrastructure, which keeps the information flowing from cable to cable or cable to device. There are various connector types, including LC, FC, ST, SC, MTRJ, MPO, MTP, DIN, E2000, MU, etc. To design a fiber optic system, optical connector selection is also a very important decision. When selecting an optical connector, you have to take polishing styles, fiber types and number of fibers all into consideration.

Polishing Styles: There are mainly three kinds of polishing styles, PC (physical contact), APC (angled physical contact), and UPC (ultra physical contact). PC, UPC and APC refer to how the ferrule of the fiber optic connectors is polished. PC connector is used in many applications. UPC connectors are often used in digital, CATV, and telephony systems. APC connectors are preferred for CATV and analog systems. The picture below shows these three kinds of polishing styles.

Polish Types

Fiber Types: Single-mode and multi-mode optical fiber are two commonly used fiber types. Accordingly, there are single-mode optical connector and multi-mode optical connector. ST and MTRJ are the popular connectors for multi-mode networks. LC connector and SC connector are widely used in single-mode systems. Single-mode fiber optic connectors can be with PC, or UPC or APC polish, while multi-mode fiber optic connectors only with PC or UPC polish.

Number of Fibers: Simplex connector means only one fiber is terminated in the connector. Simplex connectors include FC, ST, SC, LC, MU and SMA. Duplex connector means two fibers are terminated in the connector. Duplex connectors include SC, LC, MU and MTRJ. Multiple fiber connector means more than two fibers are terminated in the connector. These are usually ribbon fibers with fiber count of 4, 6, 8, 12 and 24. The most popular ribbon fiber connector is MT connector.

Conclusion

The key to designing a successful fiber optic system is understanding the performance and applications of different kinds of fibers, cable constructions and optical connectors, and then utilizing the appropriate components. Fiberstore provides a wide range of fiber optic cables and connectors. Fiber optic cables can be available in single-mode, multimode, or polarization maintaining, and they can meet the strength and flexibility required for today’s fiber interconnect applications.