Tag Archives: fiber optic connectors

What Are the Components of Optical Fiber

What are the components of optical fiber? A typical optical fiber comprises three main components: the core, which carries the light; the cladding, which surrounds the core with a lower refractive index and contains the light; and the coating, which protects the fragile fiber within.


The core, which carries the light, is the smallest part of the optical fiber. The optical fiber core is usually made of glass, although some are made of plastic. The glass used in the core is extremely pure silicon dioxide (SiO2), a material so clear that you could look through 5 miles of it as though you were looking through a household window.

In the manufacturing process, dopants such as germania, phosphorous pentoxide, or alumina are used to raise the refractive index under controlled conditions.

Optical fiber cores are manufactured in different diameters for different applications. Typical glass cores range from as small as 3.7um up to 200um. Core sizes commonly used in telecommunications are 9um, 50um and 62.5um. Plastic optical fiber cores can be much larger than glass. A popular plastic core size is 980um.


The cladding is surrounding the core and providing the lower refractive index to make the optical fiber work. When glass cladding is used, the cladding and the core are manufactured together from the same silicon dioxide-based material in a permanently fused state. The manufacturing process adds different amounts of dopants to the core and the cladding to maintain a difference in refractive indexes between them of about 1%.

A typical core may have a refractive index of 1.49 at 1300nm while the cladding may have a refractive index of 1.47. These numbers, however, are wavelength dependent. The core of the same fiber will have a different refractive index at a different wavelength.

Like the core, the cladding is manufactured in standard diameters. The two most commonly used diameters are 125um and 140um. The 125um cladding typically supports core sizes of 9um, 50um, 62.5um and 85um. The 140um cladding typically has a 100um core.


The coating is the ture protective layer of the optical fiber. The coating absorbs the shocks, nicks, scrapes, and even moisture that could damage the cladding. Without the coating, the optical fiber is very fragile. A single microscopic nick in the cladding could cause the optical fiber to break when it’s bent. Coating is essential for all-glass fibers, and they are not sold without it.

The coating is solely protective. It does not contribute to the light-carrying ability of the optical fiber in any way. The outside diameter of the coating is typically either 250um or 500um.  Generally the coating is colorless. In some applications, however, the coating is colored, so that individual optical fibers in a group of optical fibers can be identified.

The coating found on an optical fiber is selected for a specific type of performance or environment. Once of the most common types of coating is acrylate. This coating is typically applied in two layers. The primary coating is applied directly on the cladding. This coating is soft and provides a cushion for the optical fiber when it is bent. The secondary coating is harder than the primary coating and provides a hard outer surface. Acrylate, however, is limited in temperature performance. A typical acrylates may perform at temperatures up to 125º C.

Silicone, carbon, and polyimide are coatings that may be found on optical fibers that are used in harsh environments such as those associated with avionics, aerospace, and space. They may also be used on optical fibers designed for mining, or oil and gas drilling.


While many combinations of core and cladding sizes are possible, standards are necessary to ensure that connectors and equipment can be matched properly. This is especially important when dealing with components as small as those used in fiber optics, where even slight misalignments can render the entire system useless.

Two organizations publish standards that define the performance of optical fibers used in the Telecommunications industry; they are the Telecommunications Industry Association (TIA)and the International Telecommunications Union (ITU). While TIA and ITU publish many standards on optical fiber, the key standards that you should be familiar with ANSI/TIA-568-C.3, ITU-TG.653, ITU-TG.655 and ITU-T G.657.

The ANSI/TIA-568-C.3 standard is applicable to premises optical fiber cabling components. The ITU standards are applicable to Single Mode Fiber Optic Cable. The following are their descriptions:

>ITU-TG.652: Characteristics of a single mode optical fiber and cable

>ITU-T G.655: Characteristics of a dispersion shifted single mode optical fiber and cable

>ITU-T G.657: Characteristics of a non-zero dispersion-shifted single mode optical fiber and cable

These standards contain important information that defines the performance of the optical fiber, Fiber Optics Cables, and components such as Fiber Optics Connectors and splices.


Optical fibers are commonly made with a glass core and glass cladding, but other materials may be used if the fiber’s performance must be balanced with the cost of installing the fiber, fitting it with connectors, and ensuring that it is properly protected from damage. In many cases, fibers must run only a short distance, and the benefits of high quality all glass fibers become less important than simply saving money. There are also circumstances in which the fibers are exposed to harsh conditions, such as vibration, extreme temperature, repeated handling, or constant movement. Different fiber classifications have evolved to suit different conditions, cost factors, and performance requirements.

The major fiber classifications by material are

Glass fibers: These have a glass core and glass cladding. They are used when high data rates, longtransmission distances, or a combination of both are required. Glass fibers are the most fragile of the various types available, and as a result they must be installed in environments where they will not be subjected to a great deal of abuse, or they must be protected by special cables or enclosures to ensure that they are not damaged.

Glass fibers are commonly found in long-distance data and interbuilding and interoffice networking applications.

Plastic clad silica (PCS): These fibers have a glass core and plastic cladding. The core is larger than all-glass fiber; typically, 200µm with a cladding thickness of 50µm. Like a siliconecoated glass optical fiber, the plastic coating of a PCS optical fiber is typically used with a thermo-plastic buffer that surrounds the plastic cladding. A typical PCS fiber specification would be 200/300µm. The plastic cladding also serves as a protective layer for the glass core, so the coating normally found on all-glass fiber is not included on PCS fibers. PCS fibers are typically used for industrial sensing applications and medical/dental applications.

Hard-clad silica (HCS): These fibers are similar to PCS fiber but they have a glass core with cladding made of a hard polymer or other material, typically stronger than other cladding materials. Hard-clad silica fiber is commonly used in locations where ruggedness is a prime consideration, such as manufacturing, factory automation, and other areas where shock and vibration would render standard glass fibers unreliable. HCS optical fibers are typically much larger than glass optical fibers. A very popular size is 200/230µm.

Plastic fiber: These fibers have a plastic core and plastic cladding. They are selected for their low cost, ruggedness, and ease of use, and are installed where high bandwidth and long transmission distances are not required. While plastic fibers are unsuited for long-distance, high performance transmissions, they can still carry signals with useful data rates over distances of less than 100m. A very popular size is 980/1000µm. Plastic fiber is typically designed for visible wavelengths in the 650nm range. Some typical locations for plastic fiber include home entertainment systems, automotive, and manufacturing control systems. They may also be used in links between computers and peripherals and in medical equipment.

The advantages of large core plastic optical fiber

It is easy to get excited about the high bandwidth and long distance transmission capabilities of glass optical fiber. It clearly outperforms any other medium. However, many applications do not require a high bandwidth over great distances. There are many applications for optical fiber in your home. You may already have a home entertainment system that uses plastic optical fiber, or you may own a car that uses plastic optical fiber to connect audio devices or a DVD changer. None of these applications requires high bandwidth over great distances. These applications are ideal for large core plastic optical fiber.Plastic optical fiber is typically designed to operate at a visible wavelength around the 650nm range. Being able to see the light as it exits the optical fiber has a significant advantage; no expensive test equipment is required. A power meter is needed to measure the light exiting a glass optical fiber operating in the infrared range. Power meters can cost more than your home entertainment system.

The large core of the plastic optical fiber has another advantage over small glass fibers: it is easy to align with another fiber or a light source or detector. Imagine aligning two human hairs so that the ends touch and are perfectly centered. Now imagine doing the same thing with two uncooked spaghetti noodles.

ElectronicCast: 2013 Fiber Optic Connector Market Reached $ 2.39 Billon

According to the latest report from ElectronicCast consultants shows that in 2012 fiber connectors and mechanical splices sold worldwide reached $ 2.39 billion. The data center applications accounted for more than half of the optical connectivity markets. ElectroicCas said telecom operator’s demand for optical connectors will continue to grow in the next five years.

ElectronicCast report notes that in 2012 the application of optical data network connectors accounted for 51% of the total market last year for $ 1.2 billion. Telecommunication market’s demand is $ 669 million, due to fiber broadband network construction, the future of this field will maintain an average annual growth rate of 14.5%, to reach $ 1.3 billion by 2017. Fiber optic connectors, the third largest market segment for military, aerospace and other applications of products under strict conditions, in 2012 the total market are $ 270 million.

fiber connector market share

By connector type to points, 2012 single-mode fiber optic connector markets are $ 786 million, accounting for 33% of the market, mainly used in the telecommunications market. Multimode connector is mainly used for short-haul markets, such as LAN, high-performance computing, data centers, accounting for 61% of the total market. Another 6% of the market is the mechanical splices.

ElectronicCas point that advanced technology extended from optical fibers to the users, which will bring more demand for more miniaturized connectors and ribbon fiber connectors.

Published by Fiberstore, industry news – www.fs.com

Fiber Optic Patch Cable Of Cabling System Management

For cabling, telecommunication rooms and equipment rooms are the convergence of three businesses including data, voice and image, and its importance is self-evident. So making great efforts in their overall design, equipment stereotypes, hardware configuration, maintenance and other aspects of construction. However, the construction side always tends to ignore the largest number of equipment maintenance and installation of security – fiber optic cables and fiber patch cables in the telecommunications rooms and equipment rooms. While ignoring the problem will bring us a lot of trouble to the machine room management therefore I believe that it is necessary to have proper fiber optic patch cord management operations.

In general, reasonable patch cables management can be divided into five processes: planning, preparation, wiring, testing and verification.

1. Planning

For patch cables management, should be prepared the requirements planning including present and future.

1.1 Change Requests. A variety of management activities, move, add or change (MAC) all began in the change requests. Change requests must contain all the necessary information about starting the planning procedures.

1.2 Search Records. After receiving the request table, searching the coping recording, in order to determine the circuit paths used.

1.3 Correct Routing. Before determine the correct length of fiber optic patch cord, we should first find out the best route between the ports. Usually the shortest route is passing from the horizontal and vertical cable. Moreover shall not obstruct or interfere with the other jumpers or connectors in the distribution frame. When select fiber optic patch cables, should avoid excessive laxity, ensure the appearance clean and tidy. Jumper too tight will increase the pulling force of connectors, whereas overwork slack will bring trouble to jumper management, increase the patch panel’s management difficulty.

2. Preparation

Before the implementation of management, you should do prepare as much as possible, to research the management records. Determine the label information of connection and reconnect port location and the relevant ports.

2.1 First check the require patch cable model, and then check the quality of the jumper. To ensure the quality of the jumper is correct, need to check whether the jumper is damaged. In order to check it is damaged or not, of course you can from the appearance of the jumper, if possible, use professional equipment to check.
2.2  Then check the situation of the require connecting portion, in order to avoid physical damage to the connection parts.
2.3  Finally need to clean the jumper joints and the connecting parts.

There are two ways available to clean the fiber connectors: contact and non-contact.

Contact Cleaning Method:
(1). Wiping paper and anhydrous alcohol, using raw wood pulp with special processing technology, ultra-low dust, pure texture, high performance water absorption, delicate, will not scratch the surface swabbed, with a low dust wipe with no water-alcohol wipe on fiber optic connectors;
(2). Non-woven fabric, does not produce lint, tough, without any chemical impurities, silky soft, does not cause allergic reactions, and not easy to fluff and hair loss, as the ideal choice for cleaning fiber optic connectors or pins on the production or testing, wipe fiber optical connector with no water-alcohol;
(3). Cleaning cotton swabs, specifically designed for ceramic casing internal cleaning or for cleaning the ferrule end face of the flange (or adapter) which is not easy reached;
(4). Professional cleaner, fiber optic connector special cleaner uses special cleaning wiping belt, mounted in a scramble enclosure, no alcohol, each cleaning is very effective and produces a new surface, convenient and practical.

Non-Contact Cleaning Method:

(1). Ultrasonic cleaning method, it replaces clean liquid into ultrasonic “column” to the connector end surface, and waste recycling and sucked clean in the same small space;
(2). High-pressure blowing method, its principle is at the connector end first coated with cleaning fluid, and then use high-pressure gas blowing at the connector end surface;

2.4 Check the fiber optic connector cleanliness

After finish cleaning fiber optic connectors, must check the terminated surface. General practice is to use a magnifying glass 100, 200 times or 400 times to check, the figure below shows the fiber end-face in a pure state and a contaminated state.

Patch cable management person, no matter using which method mentioned above, for some serious pollution or difficult to clean connectors, needs to use cotton swabs, alcohol and other cleaning fluid to handle.

After this series of preparatory work, it means the wiring work of patch cable management is to expand.

3. Wiring

Patch panel installation, should base on operational procedures to complete various stages of any work. Patch cable construction kinks, glitches, bad pinch and bad contact are likely to significantly reduce the jumper performance. To avoid such problems, you should focus on the following factors:

(1). Bending radius
The minimum bending radius jumper allows need to comply with the jumper manufacturer operating specifications.

Standard says, the minimum bend radius of unshielded twisted pair (UTP) cable should be at four times as the diameter of fiber optic cable, shielded twisted-pair cable is as eight times as the diameter of fiber optic cable. The minimum bend radius of 2-core or 4-core horizontal cable is greater than 25mm, if the bending radius is smaller than this standard, it may lead to a change in the relative position of the wire, resulting in reduced transmission performance.

(2). Jumper tensile and stress
During wiring process, not excessive force, otherwise it may increase the stress on jumpers and connectors, resulting in decreased performance.

(3). Bundle
The jumper is not always needed bundling, if bundled strapping manufacturers need to comply with the principle, not tied too tight, otherwise it will cause a twisted pair variant. Do not over-tighten the clamp, the jumper should be able to freely rotate. Please use a dedicated product, consider choosing repeated use products without tools, such as nylon sticking with buckle belt.

4. Testing

Even after the jumper wiring completed, but may be that if the fiber links or copper links are in full compliance with operating specifications or cabling international and national standards. Then it should be fiber or copper testing, only in accordance with the testing standards, then can determine whether it passes the test standard.

5. Verification

(1). It is worth spending the time to the final visual inspection of the connection. Ensure that the jumper relaxation not knot, is not a cabinet door clamp.

(2). The final step is based on the existing configuration update records, close and have completed the change request related work orders.

Now the fiber optic cable is one of the most important components of integrated wiring system, especially good management operation of fiber jumpers in the data center project, is particularly prominent. Believe that as construction management personnel reasonably jumper management operates, will make the entire comprehensive wiring system become advanced, scientific, practical and reliable.

With the large number applications of 10G/40G/100G network in data center, on-site installation and management of fiber optic patch cable becomes increasingly important, the jumpers management sometimes affect the overall channel attenuation, good management ensures fiber channel data transmission in the most excellent condition, process-oriented operations such as planning, preparation, wiring, testing and verification have important significance to assurance the quality of the system.