Know the type of fiber, fiber cable, jumper, pigtail, and connector

To understand the types of optical fibers, optical cables, jumpers, connectors, and adapters, you first need to know the relationship between these products.

 

Optical fiber

The optical fiber is drawn from silica glass through a complicated process, it is a highly transparent glass filament, which is also called optical fiber.

Optical fiber type

Optical fiber is divided into single mode fiber and multimode fiber according to the transmission mode. Light enters the optical fiber at a specific angle of incidence, and full emission occurs between the optical fiber and the cladding. When the diameter is small, only one direction of light is allowed to pass through, which is a single-mode optical fiber; when the diameter of the optical fiber is large, light can be allowed to inject and propagate at multiple angles of incidence, that is a multimode fiber.

Single mode optical fiber

Normally, there are two types of optical fiber: single mode and multi mode. Single-mode fiber is a single glass fiber strand used to transmit a single mode or ray of light. Single mode fiber with a relatively narrow diameter, through which all signals travel straight down the middle without bouncing off the edges. Single-mode fiber features only one transmission mode. Single Mode Fiber with a relatively narrow diameter of 8.5 to 9.5μm, through which only one mode will propagate typically 1310 or 1550nm. 

Multimode optical fiber

Multi mode fiber is an optical fiber that allows multiple guided modes to be transmitted. Multi-mode fiber has a larger diameter core, typically 50 or 62.5μm. This larger core allows multiple modes of light to propagate. The standard wavelengths of the multimode are 850 nm and 1300 nm. Multimode fiber is available in four classifications: OM1 (62.5/125 µm), OM2, OM3, OM4 (50/125 µm). There’s also a new multimode fiber standard known as WBMMF (wideband multimode fiber) which uses the wavelengths between 850nm and 953nm.

Both single mode fiber and multimode fiber have a cladding diameter of 125μm.

G652，G657 fiber

According to the ITU standard, there are seven kinds of fibers: G651, G652, G653, G654, G655, G656, G657, and G652 and G657 are commonly used.

G652 fiber is the most widely used fiber in the metropolitan area network. It is a standard single-mode fiber with a zero-point dispersion of 1300nm. G652 fiber is subdivided into four types: G652A, G652B, G652C and G652D. The main difference lies in PMD. Among them, G652D is more commonly used. Because of its low fiber dispersion at 1300nm operating wavelength, the transmission distance of the system is only limited by loss.

G657 is a bending loss-insensitive fiber, and it is the most commonly used fiber optic cable for FTTH because of its better performance. But G657 fiber is more expensive than G652D.

G651 is a multi-mode optical fiber, mainly used in multi-tenant, residential buildings, and enterprise networks in FTTH networks. Its bending radius is half that of G652 fiber. It is suitable for indoor and FTTH cabling.

OS1, OS2, OM1, OM2, OM3, OM4, OM5

OS1 and OS2 are both single-mode optical fibers. OS1: the ordinary single-mode optical fiber used earlier; OS2: the ordinary optical fiber in use now, the low-water peak optical fiber. In general, OM1 is conventional 62.5/125μm; OM2 is conventional 50/125μm; OM3 is 850nm laser-optimized 50μm core multimode fiber, and in 10Gb/s Ethernet with 850nm VCSEL, the fiber transmission distance can reach 300m; OM4 is an upgraded version of OM3. OM4 multimode fiber optimizes the differential mode delay (DMD) generated by OM3 multimode fiber during high-speed transmission. Therefore, the transmission distance is greatly improved, and the fiber transmission distance can reach 550m; OM5 is a new standard for fiber patch cords defined by TIA and IEC with a fiber diameter of 50/125μm. Compared to OM3 and OM4 fiber patch cords, OM5 fiber patch cords can be used for higher bandwidth applications. The bandwidth and maximum distance are different for different levels of transmission.

 

Optical cable

The optical fiber is drawn from pure quartz with a special process into a glass tube thinner than a hair with a few mediums in the middle. Its texture is brittle and fragile, so an additional protective layer is needed. The outer layer of the optical fiber is combined with a plastic protective tube and a plastic sheath to form an optical cable.

Optical cables include fibers. Broadly speaking, optical fibers are optical cables, which are all transmission media. But they are also difference. The difference between optical fiber and optical cable: optical fiber is a thin and soft medium that transmits light beams. Most optical fibers must be covered by several layers of protective structures before use, and the covered cables including fibers are called optical cables. Therefore, the optical fiber is the core part of the optical cable, and the optical fiber forms the optical cable through the protection of some components and the auxiliary protective layer.

The type of fiber optic cable

There are many classification methods to categorize fiber optic cables, such as:

Classified by material: LSZH, PVC, HYTREL 7246, HYTREL 7237, PE, TPU

According to the outer diameter: φ0.9, φ2.0, φ3.0……

Divided by mode field: single mode (9/125), multimode (50/125, 62.5/125)

Divided by color: single mode is yellow, multimode is orange (OM1/OM2), OM3 is aqua blue, OM4 is aqua blue or violet, OM5 is lime green.

According to the structure, it can be divided into: generally simplex or duplex, duplex in single-tube, mini multicore, branch cable

Optical fiber brands: Corning, YOFC, Fujikura, Sumitomo, OFS, etc.

 

Type of patch cord

The 0.9, 2.0, and 3.0 of the optical fiber jumper are used to distinguish the outer diameter of the optical cable. 0.9 means the outer diameter of the optical cable is 0.9mm, 2.0 means the outer diameter of the optical cable is 2mm, and 3.0 means the outer diameter of the optical cable is 3mm.

There are also single-mode fiber jumpers and multi-mode fiber jumpers. Single mode is indicated by yellow, and the transmission distance is longer; multimode is indicated by orange, and the transmission distance is shorter.

 

Pigtail

Only one end of the pigtail has a connector, and the other end is a broken end of an optical cable core, which is connected to other optical cable cores through fusion splicing. It often appears in the optical fiber terminal box and is used to connect the optical cable to the optical transceiver.

Type of connector

Divided by the connection mode: FC, SC, ST, MU, LC, MT, E2000, MTRJ

Divided by fiber end face: PC, UPC, APC, SPC

According to the number of cores of the optical cable, it can be divided into: single core, double core (with clip)

Commonly used connectors: FC/PC, SC/PC, SC/APC, LC/PC

According to the tail sleeve structure, it can be divided into: round tail sleeve, square tail sleeve, conventional tail sleeve, short tail sleeve

 

Why should the fiber end face be divided into PC,UPC,APC

There are many reasons to caused fiber loss caused during fiber connections, such as: different axis (single-mode fiber coaxiality is required to be less than 0.8μm), the end face is not perpendicular to the axis, the end face is not flat, the butt core diameter is not matched, and the splicing quality is poor.

In order to make the end faces of the two optical fibers better contact, the end faces of the ferrule of the fiber jumper are usually ground into different structures. Common grinding methods are mainly: PC, APC, UPC. PC/APC/UPC represents the front surface structure of the ceramic ferrule.

 

Different fiber end face finishes

PC (Physical Contact).The two end faces are polished to be slightly curved or microspherical, and the fiber core is at the highest point of the bending. This eliminates the air gap and forces the fibers into physical contact.

UPC (Ultra Physical Contact) is based on the PC to optimize the end face polishing and surface finish, the end face looks more dome-shaped. The end face of the UPC connector is not entirely flat, and there is a slight arc to achieve more accurate connecting.

APC (Angled Physical Contact). The end face of APC is usually polishing into an 8-degree angle. The 8° angled bevel makes the fiber end face tighter and reflects light through its beveled angle to the cladding instead of returning directly to the source, providing better connection performance. 

The APC fiber optic connector is usually green. UPC/PC connectors are easily identified by their blue color on the connector boot.

Type of adapter

Optical fiber adapters are used to convert various optical fiber equipment and optical fiber connection methods. With the wide application of fiber optic adapters in fiber optic connections, there are various fiber optic adapters with different interfaces to choose from to adapt to different environmental installation requirements. Common types of adapters are: LC adapter, FC adapter, SC adapter, ST adapter, E2000 adapter, MTP / MPO adapter, etc.

 

HYC is a leading passive optical component OEM/ODM manufacturer, focusing on providing customers with efficient manufacturing, high-quality products and in-depth research and development. The main products are: fiber optic connectors (high-density optical connectors for data centers), WDM wavelength division multiplexers, PLC optical splitters, MEMS optical switches and other four core optical passive basic devices, which are widely used in fiber to the home , 4G/5G mobile communications, Internet data centers, national defense communications and other fields.

Simplex & Duplex Fiber Optic Patch Cord

 The fiber optic patch cord can be divided into two types according to the work mode of the interface, it is simplex and duplex. Then what is simplex and duplex, how to use them? They are two kinds of communication channels in telecommunications and computer networking, which provide pathways to convey information.

What is simplex fiber patch cord?

Simplex is that data transmission only supports transmission in one direction. The two ends of communication, one end is the transmitter and the other end is the receiver, which is not reversible. For example, broadcasting stations usually only send signals to audience site, and do not receive signals from audience site.

 

What is duplex fiber patch cord?

Duplex is divided into half duplex and full duplex. Half-duplex can transmit data in both directions on the signal carrier, but not at the same time. In the communication process, the transmitter and receiver at both ends of the communication system can switch the direction through the receive/transmit switch to realize transmission in a single direction. It can also be said that the half-duplex mode is a simplex communication with switchable directions. . For example, on walkie-talkie, when you press the call button, you can send a conversation to the other party, and the other party can also hear it, but the other party cannot talk to you at the same time.

Full duplex is capable of two-way data transmission in both directions of the signal carrier at the same time. Receiving data while sending data, which requires the sending end and the receiving end to have independent receiving and sending capabilities at the same time. The full-duplex mode can also be seen as a simplex communication that allows two-way simultaneous transmission. Just like a telephone, both parties can talk at the same time by using two-way instant transmission technology. The duplex jumper can be composed of two simplex jumpers through a special design. For example, the Uniboot jumper uses a single tube and dual core.

Both simplex and duplex fiber jumpers can have single-mode and multi-mode modes. Single-mode and multi-mode have different applications. Generally speaking, single-mode is compared Suitable for long-distance transmission, and multi-mode is suitable for short-distance transmission. Choose which mode of fiber jumper depends on the actual applications.

HYC has focused on the OEM/ODM manufacturing of passive optical communication devices for 20 years. It has a strong R&D team and production capacity, and can provide customers with one-stop customized production of optical communication passive basic device design, R&D and manufacturing. The production lines mainly include fiber optic connectors, fiber jumpers, PLC splitters, WDM wavelength division multiplexers, MEMS optical switches, etc.

What is the IL Value of Ultra Low Loss MPO Fiber Optic Cable?

With the wide application of FTTH, the requirements for data transmission capability and speed have become more and more important in optical fiber communications, which has also led to high requirements for high-density, low-loss optical fiber connectors.

In the previous article, we introduced what are insertion loss and return loss? These two parameters are the most important indicators of fiber optic connectors. The three factors that affect fiber connection loss are the lateral shift of the fiber core, fiber tilt and gap. Among them, lateral offset is the most important factor.

For MPO connectors, the factors that affect the lateral offset are the eccentricity of the fiber hole, the gap between the fiber hole and the fiber, and the gap between the positioning pin hole and the positioning pin. By determining the dimensional tolerances required for MT sleeves, optical fibers and positioning pins, low losses can be achieved. This requires MPO connectors to have low-loss and high-reliability performance during the grinding process, polishing process, and manufacturing process of experimental testing.

So what is low loss? First, let's take a look at the standard typical insertion loss values of MPO fiber connectors.

 Optical performance index of MPO single-mode fiber connector
－The maximum insertion loss of any plug through the standard adapter and standard plug ≤0.75dB (including repeatability); return loss>30dB (MPO/PC),>50dB (MPO/APC)
－The maximum insertion loss of two plugs connected arbitrarily through the adapter ≤1dB; return loss>20dB (MPO/PC),>40dB

 Optical performance index of MPO multimode fiber connector plug
－The maximum insertion loss of any plug through the standard adapter and standard plug ≤0.35dB (including repeatability)
－The maximum insertion loss of two plugs connected arbitrarily through the adapter ≤1dB

Although the IEC standard specifies the maximum insertion loss of the connector, the typical insertion loss of most manufacturers' connectors will be below the standard value. At present, the insertion loss index of 8-core or 12-core multimode MPO connectors in the industry is generally standard loss 0.5dB, and low loss is less than 0.35dB.

MPO/MTP fiber optic connectors are an important part of high-density optical interconnect products in data centers. Today, data center cabling also requires higher-performance, higher-density MPO/MTP fiber optic cables. By improving the connector technology and manufacturing technology, HYC Co., Ltd successfully reduced the loss of the MPO connector SM single-mode 12-core to less than 0.25dB, which is 28% lower than the industry low loss value of 0.35dB; The loss of SM single-mode 24 core is reduced to 0.35dB, which is far below the industry standard and the typical loss value of MPO connectors provided by other manufacturers. It provides high-quality MPO fiber optic cables for data center 400G network construction.

About HYC Co., Ltd
HYC can provide customized high-quality MPO/MTP optical fiber cable according to customer needs. Founded in 2000, HYC has more than 20 years of OEM/ODM manufacturing experience in optical communication devices. The main products include high-density optical connectivity, PLC optical splitters, WDM wavelength division multiplexers, MEMS optical switches and other products, which are widely used in FTTx, telecommunications, 5G networks, data centers and other fields.

Fiber Optic Patch Cable PC, APC or UPC

To make better contact between the ends of the two fibers, the ferrule end faces of the fiber optic patch cable is usually polishing into different structures. Standard polishing methods are PC, APC, and UPC. PC/APC/UPC represents the front end structure of the ceramic ferrule.

Different fiber end face finishes
PC (Physical Contact).The two end faces are polished to be slightly curved or microspherical, and the fiber core is at the highest point of the bending. This eliminates the air gap and forces the fibers into physical contact.

UPC (Ultra Physical Contact) is based on the PC to optimize the end face polishing and surface finish, the end face looks more dome-shaped. The end face of the UPC connector is not entirely flat, and there is a slight arc to achieve more accurate connecting.

APC (Angled Physical Contact). The end face of APC is usually polishing into an 8-degree angle. The 8° angled bevel makes the fiber end face tighter and reflects light through its beveled angle to the cladding instead of returning directly to the source, providing better connection performance.

Different physical appearance
The APC fiber optic connector is usually green. UPC/PC connectors are easily identified by their blue color on the connector boot.

Insertion loss and return loss
Different polishing styles determines the quality of optical fiber, which results in different performances regarding the connector's insertion loss and return loss. Insertion loss refers to the signal loss caused by the connector or cable. In general, the typical insertion loss of PC, UPC, and APC connectors should be less than 0.3dB. Compared with APC connectors, UPC connectors are usually easier to achieve low insertion loss due to the smaller air gap. Insertion loss can also be caused by a tiny particle of dust trapped between the connector end-faces. A single dry debris particle could even damage the fibers and ferrules.

Return loss, also known as reflection loss, is a parameter representing the signal reflection performance. Usually expressed in negative dB value, the higher the value of the setting, the better. The end faces of APC connectors are beveled, so the return loss of APC connectors is usually better than UPC connectors. In general, the return loss of the PC fiber cable is -40dB. UPC return loss is higher relative to PC, generally at -55dB (or even higher). APC industry-standard return loss is -65dB. With the UPC connector, any reflected light is directly reflected back to the light source. The beveled end face of the APC connector allows the reflected light at an angle into the cladding instead of reflecting it directly to the light sources. This is the main factor that causes the return loss to differ.

Applications
PC is the most common grinding method for optical fiber connectors, which is widely used in telecommunication operator equipment. UPC is commonly used in Ethernet network equipment (such as ODF fiber distribution frames, media converters and fiber switches, etc.), digital, cable television and telephone systems. APC is generally used in optical radio frequency applications such as CATV, and also in passive optical applications, such as PON network structures or passive optical local area networks.

Connector connections need to be in the same end face structure; for example, APC and UPC cannot be mated together , because doing so will resulting in poor connector performance. However, the end faces of PC and UPC fibers are flat, and the difference is in the quality of grinding. Therefore, the mixed connection of PC and UPC will not cause permanent physical damage to the connector.

HYC has 19 years of experience in research and development of fiber optic component manufacturer , supplying all kinds of fiber connectors and fiber patch cords for various specifications.

What are the advantages of OM5 fiber patch cord?

“OM” is abbreviated for optical multimode, and it is specified by the ISO/IEC 11801 international standard. Currently, TIA and IEC defined fiber patch cord standards are OM1, OM2, OM3, OM4, and OM5.

What are single-mode and multi-mode? There are two different kinds of optical fiber cables, single-mode(OS) and multimode(OM). Single-Mode Fiber is an optical fiber that allows only one mode of transmission. The core diameter is about 8 to 9μm and the outer diameter is about 125μm. Multimode Optical Fiber allows different modes of light to be transmitted over a single fiber with a core diameter of 50μm and 62.5μm. Generally, single-mode fiber supports longer transmission distances than multi-mode fiber. In 100Mbps Ethernet to 1G Gigabit, single-mode fiber can support transmission distances over 5000m. Multimode fiber is only suitable for a medium and short distance and small capacity fiber optic communication systems. Multi-mode is cost-effective for installations where the lengths don’t exceed a few hundred meters.

What is the difference between OM1, OM2, OM3, OM4, OM5?
In general, OM1 is conventional 62.5/125μm; OM2 is conventional 50/125μm; OM3 is 850nm laser-optimized 50μm core multimode fiber, and in 10Gb/s Ethernet with 850nm VCSEL, the fiber transmission distance can reach 300m; OM4 is an upgraded version of OM3. OM4 multimode fiber optimizes the differential mode delay (DMD) generated by OM3 multimode fiber during high-speed transmission. Therefore, the transmission distance is greatly improved, and the fiber transmission distance can reach 550m; OM5 is a new standard for fiber patch cords defined by TIA and IEC with a fiber diameter of 50/125μm. Compared to OM3 and OM4 fiber patch cords, OM5 fiber patch cords can be used for higher bandwidth applications. The bandwidth and maximum distance are different for different levels of transmission.

What is OM5 fiber?
OM5, previously known as wideband multimode fiber or WBMMF. Known as Wideband Multimode Fiber Patch Cable (WBMMF), OM5 fiber is a laser-optimized multimode fiber (MMF) designed to specify bandwidth characteristics for wavelength division multiplexing (WDM). The new fiber classification method is designed to support a variety of “short” wavelengths between 850 nm and 950 nm, which are suitable for high bandwidth applications after polymerization. The OM3 and OM4 are designed primarily to support a single wavelength of 850 nm.

The difference from OM3, OM4?
Jacket Color
OM1 and OM2 cable typically come with an orange jacket. OM3 and OM4 have a suggested jacket color of aqua. The color of the OM5 fiber jacket was chosen as lime green.

Different application scopes
OM1 and OM2 have been widely deployed in buildings for many years, supporting Ethernet transmissions up to 1GB. OM3 and OM4 cables are commonly used in data center cabling environments, supporting 10G or even 40/100G Fast Ethernet. Designed for 40Gb/s and 100Gb/s transmission, the OM5 reduces the number of fibers that can be transmitted at high speeds.

Type	Fiber type(μm)	Application
OM1	62.5	100Mb/s
OM2	50	1Gb/s
OM3	50	10Gb/s
OM4	50	40/100Gb/s
OM5	50	40/100/200/400Gb/s

OM5 multimode fiber features

Fewer fibers support higher bandwidth applications
The OM5 fiber patch cord has an operating wavelength of 850/1300 nm and can support at least 4 wavelengths. The typical operating wavelengths of OM3 and OM4 are 850 nm and 1300 nm. That is to say, the traditional OM1, OM2, OM3, and OM4 multimode fibers have only one channel, while the OM5 has four channels, and the transmission capacity is increased by four times. Combining short-wavelength division multiplexing (SWDM) and parallel transmission technology, OM5 only requires 8-core wideband multimode fiber (WBMMF), which can support 200/400G Ethernet applications, greatly reducing the number of fiber cores. The cabling costs of the network are reduced.

Longer transmission distance
The transmission distance of OM5 fiber is longer than that of OM3 and OM4. The OM4 fiber is designed to support a length of at least 100 meters with a 100G-SWDM4 transceiver. But OM5 fiber can support up to 150 meters in length with the same transceiver.

Fiber type Module	40G SWDM4	100G SWDM4	40GBiDi	100GBiDi
OM3	240m	75m	100m	70m
OM4	350m	100m	150m	100m
OM5	440m	150m	200m	150m

Lower fiber loss
The attenuation of the OM5 broadband multimode cable has been reduced from 3.5dB/km for the previous OM3, OM4 cable to 3.0dB/km, and the bandwidth requirement of 953 nm wavelength has been increased.

OM5 has the same fiber size as OM3 and OM4, which means it is fully compatible with OM3 and OM4. The existing cabling network does not need to be changed to apply to OM5. OM5 fiber is more scalable and flexible, which can support higher-speed network transmission with fewer multimode fiber cores. The cost and power consumption are much lower than single-mode fiber. Therefore, it will be widely used in 100G/400G/1T ultra-large data centers in the future.

HYC offers various kinds of fiber optic patch cords, including OS, OM1, OM2, OM3, OM4 OM5 fibers. HYC also provides fiber optic cables adapted to customers’ specific requirements. http://www.hyc-system.com