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The Difference Between Single Mode and Multi Mode Fiber Optics

You’ve probably heard the terms “single mode” and “multi mode” fiber optic cables. But what’s the difference between single mode and multi mode fiber optics? Well, it’s pretty simple – but you have to go INSIDE the cable for the answer.

Basically, the main difference with each type of fiber optic cable is the interior size.

Single mode fibers consist of a tiny glass core that typically has a diameter between 8.3 and 10 microns (9 microns is a popular size). The single glass strand carrier higher bandwidth than multi mode fiber optic. However, the single mode fiber optic uses one light source in a tight spectral width. The result? Single mode fiber optic is your best choice for transferring high speed data over long distances. Their unique properties make single mode less susceptible to attenuation than multi mode fiber optics.
Multi mode fibers contain much larger cores than single mode. Their cores are anywhere from 5 to 7 times larger than single mode cores. With a diameter ranging between 50 to 62.5 microns, multi mode fiber optics can accommodate a higher data volume than single mode. But with the greater capacity comes a setback – multi mode fiber optics have higher attenuation levels, so they’re typically used over shorter distances.
When choosing fiber optic cable for your network, the key considerations should be attenuation and distance. If you need to transmit less data over longer distances, use single mode fiber optic cables. For a greater data capacity over shorter distances, go with multi mode fiber optic cables. Multi mode is often used for LANs and other small networks.

Optical Cable Corporation Reports Second Quarter 2013 Financial Results

JiaFu® is internationally recognized for pioneering the design and production of fiber optic cables for the most demanding military field applications, as well as of fiber optic cables suitable for both indoor and outdoor use, and creating a broad product offering built on the evolution of these fundamental technologies.  OCC also is internationally recognized for its role in establishing copper connectivity data communications standards, through its innovative and patented technologies.

Founded in 2001, Jfiberoptic is headquartered in Roanoke, Virginia with offices, manufacturing and warehouse facilities located in each of Roanoke, Virginia, near Asheville, North Carolina and near Dallas, Texas.  OCC’s facilities are ISO 9001:2008 registered, and OCC’s Roanoke and Dallas facilities are MIL-STD-790F certified.
Optical Cable Corporation, Jfiberoptic, Procyon, Superior Modular Products, SMP Data Communications, Applied Optical Systems, and associated logos are trademarks of Optical Cable Corporation.
Further information about Jfiberoptic® is available at www.jfiberoptic.com.

FORWARD-LOOKING INFORMATION
This news release by Optical Cable Corporation and its subsidiaries (collectively, the “Company” or “OCC”) may contain certain forward-looking information within the meaning of the federal securities laws. The forward-looking information may include, among other information, (i) statements concerning our outlook for the future, (ii) statements of belief, anticipation or expectation, (iii) future plans, strategies or anticipated events, and (iv) similar information and statements concerning matters that are not historical facts. Such forward-looking information is subject to known and unknown variables, uncertainties, contingencies and risks that may cause actual events or results to differ materially from our expectations, and such known and unknown variables, uncertainties, contingencies and risks may also adversely affect Optical Cable Corporation and its subsidiaries, the Company’s future results of operations and future financial condition, and/or the future equity value of the Company.  A partial list of such variables, uncertainties, contingencies and risks that could cause or contribute to such differences from our expectations or that could otherwise adversely affect Optical Cable Corporation and its subsidiaries is set forth in Optical Cable Corporation’s quarterly and annual reports filed with the Securities and Exchange Commission (“SEC”) under the heading “Forward-Looking Information.”  Jfiberoptic’s quarterly and annual reports are available to the public on the SEC’s website at http://www.sec.gov.  In providing forward-looking information, the Company expressly disclaims any obligation to update this information, whether as a result of new information, future events or otherwise except as required by applicable laws and regulations.

Singlemode and Multimode of Fiber Optic Cables types

Understanding the characteristics of different fiber optic cables types aides in understanding the applications for which they are used. Operating a fiber optic system properly relies on knowing what type of fiber is being used and why. There are two basic types of fiber cables: multimode fiber optic cable and single-mode fiber optic cable. Multimode fiber is best designed for short transmission distances, and is suited for use in LAN systems and video surveillance. Single-mode fiber is best designed for longer transmission distances, making it suitable for long-distance telephony and multichannel television broadcast systems.

Multimode Fiber
Multimode fiber cables, the first to be manufactured and commercialized, simply refers to the fact that numerous modes or light rays are carried simultaneously through the waveguide. Modes result from the fact that light will only propagate in the fiber core at discrete angles within the cone of acceptance. This fiber type has a much larger core diameter, compared to single-mode fiber, allowing for the larger number of modes, and multimode fiber is easier to couple than single-mode optical fiber. Multimode fiber may be categorized as step-index or graded-index fiber. Multimode Step-index Fiber Figure 2 shows how the principle of total internal reflection applies to multimode step-index fiber. Because the core’s index of refraction is higher than the cladding’s index of refraction, the light that enters at less than the critical angle is guided along the fiber.

Three different lightwaves travel down the fiber. One mode travels straight down the center of the core. A second mode travels at a steep angle and bounces back and forth by total internal reflection. The third mode exceeds the critical angle and refracts into the cladding. Intuitively, it can be seen that the second mode travels a longer distance than the first mode, causing the two modes to arrive at separate times. This disparity between arrival times of the different light rays is known as dispersion, and the result is a muddied signal at the receiving end. For a more detailed discussion of dispersion, see “Dispersion in Fiber Optic Systems” however, it is important to note that high dispersion is an unavoidable characteristic of multimode step-index fiber. Multimode Graded-index Fiber Graded-index refers to the fact that the refractive index of the core gradually decreases farther from the center of the core. The increased refraction in the center of the core slows the speed of some light rays, allowing all the light rays to reach the receiving end at approximately the same time, reducing dispersion.Figure 3 shows the principle of multimode graded-index fiber. The core’s central refractive index, nA, is greater than that of the outer core’s refractive index, nB. As discussed earlier, the core’s refractive index is parabolic, being higher at the center. As Figure 3 shows, the light rays no longer follow straight lines; they follow a serpentine path being gradually bent back toward the center by the continuously declining refractive index. This reduces the arrival time disparity because all modes arrive at about the same time. The modes traveling in a straight line are in a higher refractive index, so they travel slower than the serpentine modes. These travel farther but move faster in the lower refractive index of the outer core region.

Single-mode Fiber
Single-mode fiber allows for a higher capacity to transmit information because it can retain the fidelity of each light pulse over longer distances, and it exhibits no dispersion caused by multiple modes. Single-mode fiber also enjoys lower fiber attenuation than multimode fiber. Thus, more information can be transmitted per unit of time. Like multimode fiber, early single-mode fiber was generally characterized as step-index fiber meaning the refractive index of the fiber core is a step above that of the cladding rather than graduated as it is in graded-index fiber. Modern single-mode fibers have evolved into more complex designs such as matched clad, depressed clad and other exotic structures.

Single-mode fiber has disadvantages. The smaller core diameter makes coupling light into the core more difficult. The tolerances for single-mode connectors and splices are also much more demanding. Single-mode fiber has gone through a continuing evolution for several decades now. As a result, there are three basic classes of single-mode fiber used in modern telecommunications systems. The oldest and most widely deployed type is non dispersion-shifted fiber(NDSF). These fibers were initially intended for use near 1310 nm. Later, 1550 nm systems made NDSF fiber undesirable due to its very high dispersion at the 1550 nm wavelength. To address this shortcoming, fiber manufacturers developed, dispersion-shifted fiber(DSF), that moved the zero-dispersion point to the 1550 nm region. Years later, scientists would discover that while DSF worked extremely well with a single 1550 nm wavelength, it exhibits serious nonlinearities when multiple, closely-spaced wavelengths in the 1550 nm were transmitted in DWDM systems. Recently, to address the problem of nonlinearities, a new class of fibers were introduced. These are classified as non zero-dispersion-shifted fibers (NZ-DSF). The fiber is available in both positive and negative dispersion varieties and is rapidly becoming the fiber of choice in new fiber deployment. For more information on this loss mechanism, see the article “Fiber Dispersion.”

One additional important variety of single-mode fiber is polarization-maintaining (PM) fiber. All other single-mode fibers discussed so far have been capable of carrying randomly polarized light. PM fiber is designed to propagate only one polarization of the input light. This is important for components such as external modulators that require a polarized light input. Figure 7 shows the cross-section of a type of PM fiber. This fiber contains a feature not seen in other fiber types. Besides the core, there are two additional circles called stress rods. As their name implies, these stress rods create stress in the core of the fiber such that the transmission of only one polarization plane of light is favored. Single-mode fibers experience nonlinearities that can greatly affect system performance.

Related fiber optic products:
Fiber optic patch panel, fiber optic patch cord, fiber optic connectors

Prysmian opens new fiber-optic cable plant in Romania

Cable maker Prysmian Group says it has a new fiber optic cable production facility at its campus in Slatina, Romania. The new production capability will triple the factory’s fiber-optic cable capacity to 1.5 million km, with the potential to reach 3 million km.

Prysmian manufactures energy cable and copper cable as well as fiber cable at the 40-year-old Slatina factory, one of 24 production facilities the company operates worldwide. The site began producing fiber optic cable in 2009. The plant comprises almost 100,000 m2 of space, 42,000 m2 of it covered, and employs more than 400 people.

“The investment in the new facility in Slatina is part of a major plan to further reinforce the Group’s competitiveness in this fast-changing market,” said Valerio Battista, CEO of the Prysmian Group. “Many developments are taking place in the current telecoms market. New players and services are appearing and evolution in broadband, double-play and triple-play services is dynamic. For this reason, as one of the major players in the telecom cable industry, Prysmian Group is continuously investing in this strategic sector in order to offer innovative technological solutions for the development of telecoms networks.”

Source from Jfiberoptic.com, China fiber optic cable manufacturer

The Other uses of optical fibers

Fibers are widely used in illumination applications. They are used as light guides in medical and other applications where bright light needs to be shone on a target without a clear line-of-sight path. In some buildings, optical fibers route sunlight from the roof to other parts of the building (see nonimaging optics). Optical fiber illumination is also used for decorative applications, including signs, art, toys and artificial Christmas trees. Swarovski boutiques use optical fibers to illuminate their crystal showcases from many different angles while only employing one light source. Optical fiber is an intrinsic part of the light-transmitting concrete building product, LiTraCon.

Optical fiber is also used in imaging optics. A coherent bundle of fibers is used, sometimes along with lenses, for a long, thin imaging device called an endoscope, which is used to view objects through a small hole. Medical endoscopes are used for minimally invasive exploratory or surgical procedures. Industrial endoscopes (see fiberscope or borescope) are used for inspecting anything hard to reach, such as jet engine interiors. Many microscopes use fiber-optic light sources to provide intense illumination of samples being studied.

In spectroscopy, optical fiber bundles transmit light from a spectrometer to a substance that cannot be placed inside the spectrometer itself, in order to analyze its composition. A spectrometer analyzes substances by bouncing light off of and through them. By using fibers, a spectrometer can be used to study objects remotely.

An optical fiber doped with certain rare earth elements such as erbium can be used as the gain medium of a laser or optical amplifier. Rare-earth doped optical fibers can be used to provide signal amplification by splicing a short section of doped fiber into a regular (undoped) optical fiber line. The doped fiber is optically pumped with a second laser wavelength that is coupled into the line in addition to the signal wave. Both wavelengths of light are transmitted through the doped fiber, which transfers energy from the second pump wavelength to the signal wave. The process that causes the amplification is stimulated emission.

Optical fibers doped with a wavelength shifter collect scintillation light in physics experiments.

Optical fiber can be used to supply a low level of power (around one watt) to electronics situated in a difficult electrical environment. Examples of this are electronics in high-powered antenna elements and measurement devices used in high voltage transmission equipment.

The iron sights for handguns, rifles, and shotguns may use short pieces of optical fiber for contrast enhancement.

Related fiber optical products:

Optical fiber communication

Optical fiber can be used as a medium for telecommunication and computer networking because it is flexible and can be bundled as cables. It is especially advantageous for long-distance communications, because light propagates through the fiber with little attenuation compared to electrical cables. This allows long distances to be spanned with few repeaters. Additionally, the per-channel light signals propagating in the fiber have been modulated at rates as high as 111 gigabits per second by NTT, although 10 or 40 Gbit/s is typical in deployed systems. Each fiber can carry many independent channels, each using a different wavelength of light (wavelength-division multiplexing (WDM)). The net data rate (data rate without overhead bytes) per fiber is the per-channel data rate reduced by the FEC overhead, multiplied by the number of channels (usually up to eighty in commercial dense WDM systems as of 2008). As of 2011 the record for bandwidth on a single core was 101 Tbit/sec (370 channels at 273 Gbit/sec each). The record for a multi-core fibre as of January 2013 was 1.05 petabits per second. In 2009, Bell Labs broke the 100 (Petabit per second)×kilometre barrier (15.5 Tbit/s over a single 7000 km fiber).

For short distance application, such as a network in an office building, fiber-optic cabling can save space in cable ducts. This is because a single fiber can carry much more data than electrical cables such as standard category 5 Ethernet cabling, which typically runs at 100 Mbit/s or 1 Gbit/s speeds. Fiber is also immune to electrical interference; there is no cross-talk between signals in different cables, and no pickup of environmental noise. Non-armored fiber cables do not conduct electricity, which makes fiber a good solution for protecting communications equipment in high voltage environments, such as power generation facilities, or metal communication structures prone to lightning strikes. They can also be used in environments where explosive fumes are present, without danger of ignition. Wiretapping (in this case, fiber tapping) is more difficult compared to electrical connections, and there are concentric dual core fibers that are said to be tap-proof.

Related fiber optic products: fiber optic patch cable, fiber optic jumper, fiber optic pigtail

The History about fiber optics

Fiber optics, though used extensively in the modern world, is a fairly simple, and relatively old, technology. Guiding of light by refraction, the principle that makes fiber optics possible, was first demonstrated by Daniel Colladon and Jacques Babinet in Paris in the early 1840s. John Tyndall included a demonstration of it in his public lectures in London, 12 years later. Tyndall also wrote about the property of total internal reflection in an introductory book about the nature of light in 1870: “When the light passes from air into water, the refracted ray is bent towards the perpendicular… When the ray passes from water to air it is bent from the perpendicular… If the angle which the ray in water encloses with the perpendicular to the surface be greater than 48 degrees, the ray will not quit the water at all: it will be totally reflected at the surface…. The angle which marks the limit where total reflection begins is called the limiting angle of the medium. For water this angle is 48°27′, for flint glass it is 38°41′, while for diamond it is 23°42′.” Unpigmented human hairs have also been shown to act as an optical fiber.

Practical applications, such as close internal illumination during dentistry, appeared early in the twentieth century. Image transmission through tubes was demonstrated independently by the radio experimenter Clarence Hansell and the television pioneer John Logie Baird in the 1920s. The principle was first used for internal medical examinations by Heinrich Lamm in the following decade. Modern optical fibers, where the glass fiber is coated with a transparent cladding to offer a more suitable refractive index, appeared later in the decade. Development then focused on fiber bundles for image transmission. Harold Hopkins and Narinder Singh Kapany at Imperial College in London achieved low-loss light transmission through a 75 cm long bundle which combined several thousand fibers. Their article titled “A flexible fibrescope, using static scanning” was published in the journal Nature in 1954. The first fiber optic semi-flexible gastroscope was patented by Basil Hirschowitz, C. Wilbur Peters, and Lawrence E. Curtiss, researchers at the University of Michigan, in 1956. In the process of developing the gastroscope, Curtiss produced the first glass-clad fibers; previous optical fibers had relied on air or impractical oils and waxes as the low-index cladding material.

A variety of other image transmission applications soon followed.

In 1880 Alexander Graham Bell and Sumner Tainter invented the ‘Photophone’ at the Volta Laboratory in Washington, D.C., to transmit voice signals over an optical beam. It was an advanced form of telecommunications, but subject to atmospheric interferences and impractical until the secure transport of light that would be offered by fiber-optical systems. In the late 19th and early 20th centuries, light was guided through bent glass rods to illuminate body cavities.Jun-ichi Nishizawa, a Japanese scientist at Tohoku University, also proposed the use of optical fibers for communications in 1963, as stated in his book published in 2004 in India. Nishizawa invented other technologies that contributed to the development of optical fiber communications, such as the graded-index optical fiber as a channel for transmitting light from semiconductor lasers. The first working fiber-optical data transmission system was demonstrated by German physicist Manfred Börner at Telefunken Research Labs in Ulm in 1965, which was followed by the first patent application for this technology in 1966.Charles K. Kao and George A. Hockham of the British company Standard Telephones and Cables (STC) were the first to promote the idea that the attenuation in optical fibers could be reduced below 20 decibels per kilometer (dB/km), making fibers a practical communication medium. They proposed that the attenuation in fibers available at the time was caused by impurities that could be removed, rather than by fundamental physical effects such as scattering. They correctly and systematically theorized the light-loss properties for optical fiber, and pointed out the right material to use for such fibers — silica glass with high purity. This discovery earned Kao the Nobel Prize in Physics in 2009.

NASA used fiber optics in the television cameras that were sent to the moon. At the time, the use in the cameras was classified confidential, and only those with the right security clearance or those accompanied by someone with the right security clearance were permitted to handle the cameras.

The crucial attenuation limit of 20 dB/km was first achieved in 1970, by researchers Robert D. Maurer, Donald Keck, Peter C. Schultz, and Frank Zimar working for American glass maker Corning Glass Works, now Corning Incorporated. They demonstrated a fiber with 17 dB/km attenuation by doping silica glass with titanium. A few years later they produced a fiber with only 4 dB/km attenuation using germanium dioxide as the core dopant. Such low attenuation ushered in optical fiber telecommunication. In 1981, General Electric produced fused quartz ingots that could be drawn into fiber optic strands 25 miles (40 km) long.

Attenuation in modern optical cables is far less than in electrical copper cables, leading to long-haul fiber connections with repeater distances of 70–150 kilometers (43–93 mi). The erbium-doped fiber amplifier, which reduced the cost of long-distance fiber systems by reducing or eliminating optical-electrical-optical repeaters, was co-developed by teams led by David N. Payne of the University of Southampton and Emmanuel Desurvire at Bell Labs in 1986. Robust modern optical fiber uses glass for both core and sheath, and is therefore less prone to aging. It was invented by Gerhard Bernsee of Schott Glass in Germany in 1973.

The emerging field of photonic crystals led to the development in 1991 of photonic-crystal fiber, which guides light by diffraction from a periodic structure, rather than by total internal reflection. The first photonic crystal fibers became commercially available in 2000. Photonic crystal fibers can carry higher power than conventional fibers and their wavelength-dependent properties can be manipulated to improve performance.

Related fiber optic products: fiber optic patch cord, fiber optic patch panel, fiber optic connector

Fiber Optic Patch Cable Buying Guide

Fiber optic patch cords are fiber optic cables used to attach one device to another for signal routing. It compresses in the entire electric network plank and room that wall plank and the flexibility cabinet needs. And today I would like to introduce you fiber optic patch cable.

fiber optic patch cable is with the fiber optic connectors, are upgrade version of the former MPO. MTP is with better mechanical and better performance compared with MPO. Both the MTP and MPO series cables are multi fiber connectors. There are many fiber optic channels in each single connector. Due to the feature of such multi fiber, these connectors need to use with multi fiber cables, especially the ribbon multi fiber optic cables.

Typical MTP/MPO fiber optic patch cord assemblies like MTP/MPO to 8 LC, MTP/MPO to 12 MT-RJ ,etc. Both single mode and multi-mode MPO ribbon patch cables are available and they are manufactured with various color-coded housings for easy identification. MPO fiber optic patch cord adopts precision molded MT ferrules, metal guide pins and appropriate housing to provide optical fiber alignment. The push-pull design is utilized for easy mating and removal.

MTP/MPO are usually used in ribbon fiber optic patch cords or ribbon fan out multi fiber assemblies. Made by multi-fiber ribbon materials, the MPO ribbon patch cable is an ideal connecting tool for telecommunication system, testing instruments, LAN and WAN systems, FTTX, etc. The MPO ribbon patch cable features removable housing, allowing easy replacement of pin clamps, ferrule clearing and connector repolishing. Connection integrity is assured by the spring-action side latch housing. The ribbon fiber optic cables features multi fiberglass inside each single jacket ,MTP/MPO are also multi fiberglass core inside each single connector, which means, there are several fiberglass connections in each single MTP/MPO fiber optic patch cord.

Jiafu fiber optic cable manufactures a full line of fiber optic patch cables. There are LC, SC, ST, FC, E2000, E2000, DIN, D4, SMA and DIN Fiber Optic Patch Cables, which classified by connector types. In addition to standard patch cords, JiaFu also provides several kinds of specialty patch cords, such as ribbon fan-out cords, MTP / MPO patch cords, mode conditioning patch cords, armored patch cord and water proof pigtails.

Through there are so many types of fiber optic patch cords, I am going to suggest you a buying guide to helping you select the correct fiber patch cable that meets your demand.

1.Choose fiber optic connectors ST, SC, LC, FC, SC/APC, LC/APC, FC/APC, FDDI, SMA, MTP, MPO, MTP/APC, MPO/APC.

2.Choose Fiber Mode, Single Mode 9/125µm OS1, Multimode 62.5/125µm OM1, Multimode 50/125µm OM2, Multimode 50/125µm OM3 10Gigabit, Multimode 50/125µm OM4, Multimode 100/140, Multimode, 200/230.

3.Choose Fiber Cable Construction Type, Simplex fiber optic cable (A single fiber), Duplex fiber optic cable (2 fibers in a single cable, Zip Cord), Multi-Fiber cables, custom configurations, common are 4 fiber, 6fiber, 8fiber, 12 fiber, 24 fiber, 48 fiber, 72 fiber, 144 fiber, 256 fiber. Higher fiber counts are normally terminated as a MTP/MPO Trunk cables, using MTP/MPO connectors.

4.Choose Fiber Cable Diameter, In stock/Most common are 3.0mm Jacket OD. Optional are 2.0mm, 1.8mm, 1.6mm.

5.Choose Fiber Optic Cable Jacket Color. Industry Standard fiber optic cable jacket colors are. SM Yellow, MM 62.5 Orange, MM 50 OM2 Orange, MM 50 10Gb OM3 Aqua/Light Blue, Optional are Blue, Orange, Green Brown, Gray/Slate, White, Red, Black, Yellow, Purple, Pink, Aqua.

6.Choose Jacket material type, PVC jacket, Riser jacket, Plenum Jacket, Armored Jacket.

7.Choose fiber patch cord length option, normally measured in Meters. Optional lengths, CM, mm, Inches, Foot, KM, Mile.