Application of Fiber Transceiver in Fiber-optic communication

by Fiber-MART.COM

Data transmission distance primarily governs the choice of fiber optic transceiver type and optical fiber. When working with distances up to 2 km, use multimode optical-fiber cable. Singlemode optical-fiber cable, however, is more bandwidth-intensive and has less potential for modal dispersion and noise than multimode optical-fiber cable, translating to the ability to transmit beyond the distance limitations of multimode. Achieving long distance transmission with fiber optic transceivers is not difficult with the proper network tools. Single strand fiber solutions are the simplest way to long distance transmission. In this page we will introduce the application of fiber optic transceiver in the network construction progress which combines with this experience.

 

Use Optical Transceivers Rather Than Copper for Shorter Distance Applications

 

Copper SFPs provide a high-speed RJ45 data connector interface for unshielded, twisted-pair copper cable. The 1000BASE-T copper SFP allows a maximum link distance of up to 100 m. For 1Gbps Cisco SFP modules, if the optical transmission distance is less than 275 metres, multimode or single-mode optical fibre and any type of transceiver (figure shown below is a Cisco GLC-SX-MM OEM SFP) can be used. If the transmission distance is between 275 and 500 metres, 50/125-micron multimode or single-mode optical fibre and any type of transceiver can be used.

 

glc sx mm price

Use Single- module SFP Transceivers for Long Distance Fiber Network Applications

 

If the transmission distance exceeds 500 metres, only single-mode optical fibre and a long wave laser transceiver can be used. With the IEEE802.3ae tandard, seven new media types were defined for LAN, metropolitan area network and wide area network connectivity:

 

1000BASE-SX SFP for Multimode Fiber Only – link lengths up to 550m

1000BASE-LX/LH SFP for Both Multimode and Single-Mode Fibers - link lengths up to 10km on SMF and up to 550m on MMF.

1000BASE-EX SFP for Long-Reach Single-Mode Fibers - link lengths up to 40km.

1000BASE-ZX SFP for Long-Reach Single-Mode Fibers - link lengths up to 70km.

Use Dual-rate Optical Transceivers for Long-Reach Fiber Network Applications

 

The dual-rate SFP is interoperable with the IEEE 100BASE-LX and 1000BASE-LX/LH standards. In a dual-fiber single network configuration, it takes a group of fiber optic transceivers to achieve the desired electrical signal and light signal. When fiber optic transceivers are arranged in a group, they may exchange electrical signals and light signals. Fiber optic transceiver ports can be configured in adaptive mode.

 

Use 1000BASE-BX10 SFPs for Single-Fiber Bidirectional Applications

 

As we known, the 1000BASE-BX-D and 1000BASE-BX-U SFPs, compatible with the IEEE 802.3ah 1000BASE-BX10-D and 1000BASE-BX10-U standards, operate on a single strand of standard SMF. The1000Base-BX10 specification provides single-mode, single fiber support at a signaling speed of 1250 Mbps for a span of 10 km or greater depending on fiber type. The two wavelength ranges employed are:

 

Downlink at 1480 to 1500 nm

Uplink at 1260 to 1360 nm

Single-mode fiber enjoys lower fiber attenuation than multimode fiber and retains better fidelity of each light pulse, as it exhibits no dispersion caused by multiple modes. Thus, information can be transmitted over longer distances. 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.

 

Originally published at www.fiber-mart.com

How to Use Field Assembly Connector?

by Fiber-MART.COM

The expansion of FTTH application has brought prosperity to the manufacturing of field assembly connectors for fast field termination. This type of connector gains its popularity due to the applicability to cable wiring and compact bodies which are easily stored in optical fiber housings. With excellent features of stability and low loss, field assembly connector has now become a reliable and durable solution for fiber optic systems. However, do you really know the field assembly process of the connector? This article provides an easy guide to show you the way of using field assembly connector.

 

Introduction to Field Assembly Connector

Before getting to know the instruction process, let’s have a look at the basic knowledge about field assembly connector. Field assembly connector or fast connector is an innovative field installable optical fiber connector designed for simple and fast field termination of single fibers. Without using additional assembling tools, field assembly connector can be quickly and easily connected to the drop cable and indoor cable, which saves a lot of required termination time. It is specially designed with the patented mechanical splice body that includes a factory-mounted fiber stub and a pre-polished ceramic ferrule. Field assembly connector is usually available for 250 µm, 900 µm, 2.0 mm and 3.0 mm diameter single-mode and multimode fiber types. The whole installation process only takes about 2 minutes which greatly improves the working efficiency.

 

field-assembly-connector

 

Internal Structure of Field Assembly Connector

From the following figure, we can see the specific internal structure of field assembly connector. The ferrule end face of the connector is pre-polished in a factory for later connection with the fiber. A mechanical splice is also formed at the end of the ferrule for mechanical fixation of optical fiber. The mechanical splice consists two plates, one with a V groove, another with flat surface above the V groove, and a clamp for the insertion of the two plates. When inserting the fiber, a wedge clip will keep the V groove open for easier installation. After the fiber insertion, the wedge clip can be extracted from the V groove.

 

structure-of-field-assembly-connector

 

Features and Applications

Key Features

Field-installable, cost-effective, user-friendly

No requirement for epoxy and polishing

Quick and easy fiber termination in the field

No need for fusion splicer, power source and tool for pressure

Visual indication of proper termination

Applications

Fiber optic telecommunication

Fiber distribution frame

FTTH outlets

Optical cable interconnection

Cable television

Field Assembly Instruction Guide

Although it is an simple way to use field assembly connector, the right operation process is also important. Here will introduce some basic steps for connector installation.

 

Step 1, prepare the field assembly connector parts and related tools required during the process. There is no need for special tools, but fiber cleaver and jacket stripper are still necessary.

 

Step 2, insert the connector boot into the fiber cable.

 

Step 3, cut and reserve 10mm bare fiber by fiber cleaver and then make sure the total fiber length of 30 mm.

 

Step 4, insert the fiber from bottom until the stopper and make fiber present micro bend.

 

Step 5, press the press cover to tight the bare fiber.

 

Step 6, lock the boot with yarn.

 

Step 7, cut the yarn.

 

Step 8, screw the boot and put on housing to complete assembly.

 

 

 

Precautions

Here are some precautions for you to notice during the process:

 

Point 1, the product is sensitive to dirt and dust. Keeping it away from any possible contamination is necessary.

 

Point 2, the performance will be influenced by the fiber cutting surface condition. Use a cutter with a sharp blade for the best results.

 

Point 3, insert the fiber into the connector slowly. If the fiber is roughly inserted, it might be damaged or broken, leading to failure of connector installation. Broken fiber could scatter in all directions.

 

Point 4, do not remove the dust cap until the connector has been completely assembled in order not to cause a high insertion loss.

 

Point 5, a proper amount of index matching gel is applied in the connector. Do not insert fiber more than once into connector.

 

Conclusion

Fiber assembly connector enables quick termination to improve reliable and high connector performance in FTTH wiring and LAN cabling systems. All the above solutions provided by fiber-mart.COM are available to meet your requirements. Please visit the website for more information.

Fiber Splitter for FTTH Applications

Passive optical network (PON) has been widely applied in the construction of FTTH (fiber to the home). With PON architecture, network service providers can send the signal to multiple users through a single optical fiber, which can help them save great costs. To build the PON architecture, optical fiber splitter is necessary.

 

What Is Fiber Splitter?

The fiber splitter is a passive component specially designed for PON networks. Fiber splitter is generally a two-way passive equipment with one or two input ports and several output ports (from 2 to 64). Fiber splitter is used to split the optical signal into several outputs by a certain ratio. If the ratio of a splitter is 1×8 , then the signal will be divided into 8 fiber optic lights by equal ratio and each beam is 1/8 of the original source. The splitter can be designed for a specific wavelength, or works with wavelengths (from 1260 nm to 1620 nm) commonly used in optical transmission. Since fiber splitter is a passive device, it can provide high reliability for FTTH network. Based on the production principle, fiber splitters include Planar Lightwave Circuit (PLC) and Fused Bionic Taper (FBT).

 

PLC Splitters

PLC splitters are produced by planar technology. PLC splitters use silica optical waveguide technology to distribute optical signals from central office to multiple premise locations. The output ports of PLC splitters can be at most 64. This type of splitters is mainly used for network with more users.

 

The Structure of PLC splitters

Internal Structure

 

The following figure shows a PLC splitter. The optical fiber is splitted into 32 outputs. PLC chip is made of silica glass embedded with optical waveguide. The waveguide has three branches of optical channels. When the light guided through the channels, it is equally divided into multiple lights (up to 64) and transmitted via output ports.

 

1x32-plc-splitter

 

Outside Configuration

 

Bare splitter is the basic component of PLC fiber splitter. For better protection of the fragile fiber and optimized use, PLC splitters are often equipped with loose tube, connector and covering box. PLC splitters are made in several different configurations, including ABS, LGX box, Mini Plug-in type, Tray type, 1U Rack mount, etc. For example, 1RU rack mount PLC splitter (as shown in the figure below) is designed for high density fiber optical distribution networks. It can provide super optical performance and fast installation. This splitter is preassembled and fibers are terminated with SC connectors. It’s ready for immediate installation.

 

rack-mount-plc-spllitter

 

FBT Splitters

FBT splitters are made by connecting the optical fibers at high temperature and pressure. When the fiber coats are melted and connected, fiber cores get close to each other. Then two or more optical fibers are bound together and put on a fused taper fiber device. Fibers are drawn out according to the output ratio from one single fiber as the input. FBT splitters are mostly used for passive networks where the split configuration is smaller.

 

PLC Splitters From fiber-mart.COM

Fiberstore offers a wide range of PLC splitters that can be configured with 1xN and 2xN. Our splitters are designed for different applications, configurations including LGX, ABS box with pigtail, bare, blockless, rack mount package and so on.

An Easy Guide to MPO/MTP Polarity

Nowadays, many data centers are migrating into the 40G and 100G transmission. To prepare for this change, MPO/MTP technology is applied to meet the requirements of high density patching. Typically, a fiber optic link needs two fibers for full duplex communications. Thus the equipment on the link should be connected properly at each end. However, high density connectivity usually requires more than two fibers in a link, which makes it more complex to maintain the correct polarity across a fiber network, especially when using multi-fiber MPO/MTP components for high data rate transmission. Therefore, many technicians would prefer to use pre-terminated MPO/MTP components designed with polarity maintenance for easier installation. This article will specifically guide you to understand the polarity of MPO/MTP products and the common polarization connectivity solutions.

What Is Polarity?

Keeping the right polarity is essential to the network. A transmit signal from any type of active equipment will be directed to the receive port of a second piece of active equipment and vice versa. Polarity is the term used in the TIA-568 standard to explain how to make sure each transmitter is correctly connected to a receiver on the other end of a multi-fiber cable. Once the component is connected to the wrong polarity, the transmission process will be unable to go on.

Structure of MPO/MTP Connector

When discussing about the polarity, MPO/MTP connector is an important component for you to know. An MPO/MTP connector has a key on one side of the connector body. There are two positions of the key – key up or key down. Key up position means that the key sits on top. When the key sits on the bottom, it is the key down position. Moreover, the fiber holes in the connector are numbered in sequence from left to right named as P1 (position 1), P2, etc. Each connector is additionally marked with a white dot on the connector body to designate the P1 side of the connector when it is plugged in. The MPO/MTP connector can be further divided into female connector and male connector. The former has no pins while the latter has two pins on the connector. The following picture shows the basic structure of MPO/MTP connector.

structure-of-mpo-connector

Connecting Methods of A, B, C

The TIA standard defines two types of duplex fiber patch cables terminated with LC or SC connectors to complete an end-to-end fiber duplex connection: A-to-A type patch cable is a cross version and A-to-B type patch cable is a straight-through version. Based on this, there are three polarity connecting methods for MPO/MTP products. Here will introduce them in details.

duplex-patch-cable

Method A is the most straight-forward method. It uses straight-through patch cords (A-to-B) on one end that connect through a cassette (LC-to-MPO or SC-to-MPO depends on what the equipment connector is), a straight-through MPO/MTP key up to key down backbone cable and a “cross-over” patch cord (A-to-A) at the other end.

method-a

Method B is the “cross-over” occurred in the cassette. The keys on the MPO cable connectors are in an up position at both ends, but the fiber that is at connector P1 in one end is in P12 at the opposite end, and the fiber that is in P12 at the originating end is in P1 at the opposing end. Only A-to-B type patch cord is needed for this method.

method-b

Method C is the most complicated. There is pair-wise “cross-over” in the backbone cable. A-to-B patch cords are used on both ends. The cassette uses MPO/MTP key up to key down and the backbone cable is pair-wise flipped so P1, P2 connects to P2, P1 and P3, P4 connects to P4, P3, etc.

method-c

Conclusion

Knowing the polarity of MPO/MTP system helps you better upgrade the 40G and 100G networks. According to different polarity methods, choosing the right MPO/MTP patch cables , connectors and cassettes will provide greater flexibility and reliability for your high density network.

Fibre optic splicing introduction

Fibre optic splicing introduction

Rather than using optical fibre connectors, it is possible to splice two optical fibres together. An fibre optic splice is defined by the fact that it gives a permanent or relatively permanent connection between two fibre optic cables. That said, some manufacturers do offer fibre optic splices that can be disconnected, but nevertheless they are not intended for repeated connection and disconnection.

There are many occasions when fibre optic splices are needed. One of the most common occurs when a fibre optic cable that is available is not sufficiently long for the required run. In this case it is possible to splice together two cables to make a permanent connection. As fibre optic cables are generally only manufactured in lengths up to about 5 km, when lengths of 10 km are required, for example, then it is necessary to splice two lengths together.

Fibre optic splices can be undertaken in two ways:

• Mechanical splices
• Fusion splices

The mechanical splices are normally used when splices need to be made quickly and easily. To undertaken a mechanical fibre optic splice it is necessary to strip back the outer protective layer on the fibre optic cable, clean it and then perform a precision cleave or cut. When cleaving (cutting) the fibre optic cable it is necessary to obtain a very clean cut, and one in which the cut on the fibre is exactly at right angles to the axis of the fibre.

Once cut the ends of the fibres to be spliced are placed into a precision made sleeve. They are accurately aligned to maximise the level of light transmission and then they are clamped in place. A clear, index matching gel may sometimes be used to enhance the light transmission across the joint.

Mechanical fibre optic splices can take as little as five minutes to make, although the level of light loss is around ten percent. However this level of better than that which can be obtained using a connector.

Fusion splices form the other type of fibre optic splice that can be made. This type of connection is made by fusing or melting the two ends together. This type of splice uses an electric arc to weld two fibre optic cables together and it requires specialised equipment to perform the splice. The protective coating from the fibres to be spliced is removed from the ends of the fibres. The ends of the fibre optic cable are then cut, or to give the correct term they are cleaved with a precision cleaver to ensure that the cuts are exactly perpendicular. The next stage involves placing the two optical fibres into a holder in the fibre optic splicer. First the ends if the cable are inspected using a magnifying viewer. Then the ends of the fibre are automatically aligned within the fibre optic splicer. Then the area to be spliced is cleaned of any dust often by a process using small electrical sparks. Once complete the fibre optic splicer then uses a much larger spark to enable the temperature of the glass in the optical fibre to be raised above its melting point and thereby allowing the two ends to fuse together. The location spark and the energy it contains are very closely controlled so that the molten core and cladding do not mix to ensure that any light loss in the fbre optic splice is minimised.

Once the fibre optic splice has been made, an estimate of the loss is made by the fibre optic splicer. This is achieved by directing light through the cladding on one side and measuring the light leaking from the cladding on the other side of the splice.

The equipment that performs these splices provides computer controlled alignment of the optical fibres and it is able to achieve very low levels of loss, possibly a quarter of the levels of mechanical splices. However this comes at a process as fusion welders for fibre optic splices are very expensive.

Mechanical and fusion splices

The two types of fibre optic splices are used in different applications. The mechanical ones are used for applications where splices need to be made very quickly and where the expensive equipment for fusion splices may not be available. Some of the sleeves for mechanical fibre optic splices are advertised as allowing connection and disconnection. In this way a mechanical splice may be used in applications where the splice may be less permanent.

Fusion splices offer a lower level of loss and a high degree of permanence. However they require the use of the expensive fusion splicing equipment. In view of this they tend to be used more for the long high data rate lines that are installed that are unlikely to be changed once installed.