2019年3月28日星期四

What is a Direct Modulated Optical Transmitter

by www.fiber-mart.com
 Today, let’s learn about a optical transmitter, especially called Direct Modulated Optical Transmitter equipment via three topics: working principle, products preview and Performance Features.
 
Working Principle
 Modern fiber-optic communication systems generally include an optical transmitter to convert an electrical signal into an optical signal to send into the optical fiber, a cable containing bundles of multiple optical fibers that is routed through underground conduits and buildings, multiple kinds of amplifiers, and an optical receiver to recover the signal as an electrical signal. The information transmitted is typically digital information generated by computers, telephone systems, and cable television companies.
 
  Laser is the most expensive machine components, machines equipped with microprocessors. The microprocessor software to monitor the working state lasers, operating parameters from the panel LCD display. Once the laser operating parameters deviate from the permissible range set by the software, the microprocessor will automatically turn-off laser power. Flashing yellow light prompts alarm panel LCD prompts cause of the malfunction (non-human factors that can not be damaged laser). RF pre-distortion technology, ensuring the case of CSO-performance system for maximum CNR.
 
FOT series Optical Transmitter products adopt the high linearity, optical isolation, the DFB, thermoelectric cooling DFB laser produced by ORTEL 、AOI、Fujitsu、Mitsubishi and other world-renowned semiconductor companies. It can provide high-quality images, digital or compressed digital signal long-distance transmission for cable television and telephone communications. Built-in RF driver amplifier and control circuitry to ensure the machine’s CNR, CTB, CSO target. Comprehensive and reliable optical circuits and laser output power stability Temperature stability of thermoelectric cooler control circuit to ensure optimal machine performance and long-life laser stability.
 
Quality: original system optimization control technology and RF pre-distortion technology ensure that the system can acquire the maximum CTB, CSO, and SBS targets in the case of excellent performance CNR.
Reliability: The 19 “1U standard rack, built-in high-performance dual switching power supply,it can work in the backup at 85 ∽ 265Vac City Network Voltage, MS-level automatic switching; chassis cooling automatic temperature control.
 
Intuitive: The laser is the most expensive machine components, machine equipped with microprocessor monitors the working state of the laser, the panel LCD window displays the operating parameters. Once the laser operating parameters deviate from the permissible range set by the software, micro-processing will automatically turn off laser power, yellow light goes on to warn, the panel LCD prompts the cause of troubles.
 
Power plug: Aluminum structure using plug switching power supply, allows for heat dissipation and replacement. And dual power supply hot and cold backup.

Learn about EDFA equipment in few minutes

by www.fiber-mart.com
WDM EDFA used to combine CATV signal from optical transmitter with internet signal from OLT and output to single fiber.
 
EDFA product overview
 
An Erbium-Doped Fiber Amplifier (EDFA) is a device that amplifies an optical fiber signal (from CATV). An WDM EDFA is used to integrated 1550nm CATV (optical signal) and 1490nm /1310nm data stream from the PON into single fiber transmission.
 
FOT EDFA series of products adopt 980nm or 1480nm high linearity, optical isolation, the DFB, thermoelectric cooling DFB laser produced by JDS, Fujitsu, Nortel, Lucent, Fitel and other world-renowned semiconductor companies as the pumping source.
 
In the interior of the machine is equipped with the light power export stable circuit and laser Thermoelectric cooling device Temperature stability control circuit to ensure optimal machine performance and long-life laser stability. The microprocessor software monitor the lasers’ working state, the Digital Panel (VFD) displays the operating parameters. Once the laser operating parameters deviate from the permissible range set by the software, micro-processing will automatically turn off laser power, red light goes on to warn, digital panel prompts cause of troubles., a detailed report of the device parameters please read FOT EDFA user manual.
 
EDFA and optical communications
EDFA (Erbium Doped Fiber Amplifier) is a representative one in the optical amplifier. As the EDFA’s wavelength is 1550nm, it is in line with the low-loss band of fiber and its technology has been relatively mature, so widely used.
 
Erbium-doped fiber is the core components of the EDFA, it makes quartz optical fiber as matrix material, and incorporate a certain proportion of rare earth element erbium ions (Er3 +) in the core of a fiber. When certain amount of pump light is injected into the erbium-doped fiber, Er3 + have been excited from the low-energy level to the high energy level, due to Er3 + has a very short lifespan on the high energy level, and soon transit to a higher level by the form of a non-radiative, and form the population inversion distribution between this energy level and low-energy-level. Because the energy between these two energy levels is exactly equal to the photon energy of 1550nm, stimulated emission of 1550nm light can only occur, we can only enlarge 1550nm optical signal.
 
EDFA has revolutionized optical communications
All optical and fiber compatible
Wide bandwidth, 20~70 nm
High gain, 20~40 dB
High output power, >200mW
Bit rate, modulation fromat, power and wavelength insensitive
Low distortion and low noise (NF<5dB)
 
Basic principle of EDFA
A relatively high-powered beam of light is mixed with the input signal using a wavelength selective coupler. The input signal and the excitation light must be at significantly different wavelengths. The mixed light is guided into a section of fibre with erbium ions included in the core. This high-powered light beam excites the erbium ions to their higher-energy state. When the photons belonging to the signal at a different wavelength from the pump light meet the excited erbium atoms, the erbium atoms give up some of their energy to the signal and return to their lower-energy state.
 
A significant point is that the erbium gives up its energy in the form of additional photons which are exactly in the same phase and direction as the signal being amplified. So the signal is amplified along its direction of travel only. This is not unusual – when an atom “lases” it always gives up its energy in the same direction and phase as the incoming light. Thus all of the additional signal power is guided in the same fibre mode as the incoming signal. There is usually an isolator placed at the output to prevent reflections returning from the attached fibre. Such reflections disrupt amplifier operation and in the extreme case can cause the amplifier to become a laser. The erbium doped amplifier is a high gain amplifier.

The release of Draft Specification for Next Generation 100Gbps Optical Interconnect Systems

by www.fiber-mart.com
Recently, 100G Lambda Multi-Source Agreement (MSA) Group announces the release of draft specifications based on PAM4 optical technology at 100 Gbps per wavelength. Member companies at MSA address the technical challenges of implementing optical interfaces with 100 Gbps per wavelength PAM4 technology and multi-vendor interoperability for optical fiber manufacturers of varying manufacturer and form factor variations . The goal of this new optical specification is for next-generation network devices that, on demand, will need to meet the industry’s growing demand for higher bandwidth and bandwidth density.
 
100G Lambda MSA team members include: Alibaba, Applied OptoElectronics, Arista Networks, Broadcom, Infocomm, Cisco, Phoenix, Hong Teng Precision Technology Co., Ltd., Inphi, Intel, Juniper Networks, Lumentum, Luxtera, Magnesium Microwave Technology, MaxLinear, Microsoft, Molex, Synaptic, Nokia, Orlano, Semtech, Saul Optoelectronics, and Sumitomo Electric.
 
The 100G Lambda MSA-defined new interface increases the distance between 100 GbE and 400 GbE applications over the 500m transmission distance interface currently defined by 100 Gbps (100GBASE-DR) and 400 Gbps (400GBASE-DR4) as defined by the IEEE 802.3 Ethernet standard . Optical specifications developed for 100 GbE at 100G Lambda MSA can achieve transmission distances of 2 to 10 kilometers and optical specifications developed at 400 GbE can achieve transmission distances of up to 2 kilometers on duplex single-mode fiber. The 100G Lambda MSA focuses primarily on 100 Gbps per wavelength and enables a complete ecosystem of technologies for the next generation of network equipment.
 
 The 100G Lambda MSA specification is available at their website 100GLambda. It is expected that MSA Group will complete the full set of specification development by early 2018. Companies will be invited to join the league as contributing members.

2019年3月26日星期二

Benefits of Using Fiber Optic Attenuators with Doped Fiber

by www.fiber-mart.com
Fiber optic attenuators are used in networking applications where an optical signal is too strong and needs to be reduced. There are many applications where this arises, such as needing to equalize the channel strength in a multi-wavelength system or reducing the signal level to meet the input specifications of an optical receiver. In both scenarios, reducing the optical signal strength is necessary or else system performance issues may arise.
 
Types of Fiber Optic Attenuators
There are many forms which can be taken by optical attenuators, but the two basic types of fiber optic attenuators are fixed and variable. In this article, we will focus on the fixed type. 
 
The size of the build out attenuator is approximately 1.25 inch. Many have a male interface connector at one end and a female interface connector at the other end but female to female interface connectors are also available. The fabrication of the build-out style is typically accomplished using with air gap attenuation or doped fiber attenuation.
 
What are Air Gap Attenuators?
Air gap attenuators accomplish the loss of optical power with the help of two fibers that are separated by air to yield the loss. These attenuators can be fixed or variable, but a downside is that they can be vulnerable to dust contamination and are also vulnerable to changing temperatures and moisture. One must also be cautious where they are used. For example, multi-channel analog systems, like ones used by CATV, this attenuator can create second order distortions that reduce the performance of the system.
 
What are doped Fiber Attenuators?
As the name suggests, doped fiber attenuators consist of a small fiber piece along with metal ion doping which provides the exact attenuation and interfaces in between female and male connections on the attenuators. These types can be wavelength sensitive because of their fabrication. The primary reasons why these doped fiber attenuators are preferred include:
 
Not susceptible to dirt, moisture, or temperature variations
Provide a stable performance over wide wavelength variations and band passes.

Eliminate the “Dead Zone” With an OTDR Launch Box

by www.fiber-mart.com
The Optical Time Domain Reflectometer (OTDR) is a vital tool for fiber optic testing that can analyze the performance of fiber optic cabling through the use backscattering technologies, as well as identifying and locating connectors, splices, and breaks in fiber optic networks.
 
However, there is an unwanted phenomenon known as ‘dead zone’ that occurs when using an OTDR, which can cause improper readings if the right steps aren’t taken. This dead zone limitation can be avoided through the use of an OTDR Launch Box, which is what we review in more detail here.
 
The Launch Box Basics
 
The launch box, which is also known in the industry as a launch fiber, pulse suppressor, dead zone box or fiber ring, is a device that helps to eliminate the dead zone issue during fiber optic testing significantly. The dead zone is something that occurs when the pulse width changes and causes a high degree of reflection that can cover an area several hundred meters from where the OTDR is located. This results in the OTDR device not being able to detect events or issues in that area.
 
A term launch box is a box that contains a long spool of fiber that is placed in between the fiber being tested and the OTDR. This provides extra fiber on which the dead zone can occur. This enables the OTDR to now detect events at the beginning of the fiber being tested.
 
Using Your Launch Box
 
Launch boxes come in various shapes and sizes. However, all tend to have a robust outer casing to make them more durable. Each end of the fiber is terminated, with one to be attached to the OTDR and the other to the fiber being tested. Once connected to the relevant ports, the test can be run accordingly.
 
While using an OTDR box is a relatively simple process, you must be sure that it contains a sufficient length of fiber to take account of the entire dead zone or you still won’t achieve a proper reading on your trace and could miss events. Choosing the right OTDR launch box is important, as they can be customized to the specific application or device.
 
hoosing the Right One
 
When choosing the right OTDR launch box for your needs, you should approach it in the same way as you would choose a fiber patch cable. Box styles along with features such as connector type, fiber type, and fiber length should all be determined. Furthermore, some launch boxes are available with bulkhead adapters while others provide directly terminated fiber ends.
 
As mentioned before, a dead zone can cover several hundred meters, so your launch box spool should be long enough to cater for this. It is important to make sure you choose one that suits the job, and your OTDR user manual can provide guidance regarding the expected dead zones.

Fusion or Mechanical: Which Is the Best Splicing Method?

When splicing together two lengths of fiber optic cabling, you have to choose between the two known methods - fusion splicing and mechanical splicing - which both essentially produce the same result - a secure connection between two formerly separate lengths of fiber.

However, how do you choose between them? Is one method better than the other? Well, in this article, we take a closer look at both, to provide some clarity on the subject. By reading to the end, you’ll know what the pros and cons are of each, how each connection is created and you’ll be in a better position to make a considered decision. 

So, without any further delay, let’s begin.

Defining Mechanical & Fusion Splicing

The ultimate goal of cable splicing is to create a secure connection between two or more sections of fiber in a way that allows the optical signal to pass through with minimal loss. As we mentioned already, both mechanical and fusion splicing achieve this goal, but they do so in very different ways. 

Fusion Splicing

Firstly, fusion splicing involves melting the two sections of fiber permanently together. This is achieved with an electrical device aptly known as a fusion splicer, and it’s something that not only melts the two parts together with an electric arc, but it is also able to align the fiber to create a good connection precisely.

Mechanical Splicing

One of the main differences with mechanical splicing is that it doesn’t permanently join the fibers together, instead of locking and aligning the pieces together with a screw mechanism. This method requires no heat or electricity at all.

The Fusion Splicing Steps

Figure 2: fusion splicer showing fiber positioning

With both mechanical and fusion splicing techniques, there are four distinct steps to the process. The first two steps for each are almost identical, but the final two are where the differences lie. 

Fusion Splicing Step 1 - Preparation

To prepare the fiber for splicing, you need to strip away the jacket or sheath that surrounds the internal glass fiber. You’ll be left with bare glass when you’re finished, which should then be cleaned with an alcoholic wipe.

Fusion Splicing Step 2 - Cleaving

The next step involves cleaving the fiber, which shouldn’t be confused with cutting. Cleaving means that the fiber should be lightly scored and then flexed until it naturally breaks. To create a sound connection, you need a good, clean, smooth cleave that’s perpendicular to the fiber it’s being connected to in the fusion splicer.

2019年3月24日星期日

What is a Direct Modulated Optical Transmitter

by www.fiber-mart.com
  Today, let’s learn about a optical transmitter, especially called Direct Modulated Optical Transmitter equipment via three topics: working principle, products preview and Performance Features.
 
Working Principle
  Modern fiber-optic communication systems generally include an optical transmitter to convert an electrical signal into an optical signal to send into the optical fiber, a cable containing bundles of multiple optical fibers that is routed through underground conduits and buildings, multiple kinds of amplifiers, and an optical receiver to recover the signal as an electrical signal. The information transmitted is typically digital information generated by computers, telephone systems, and cable television companies.
 
 Laser is the most expensive machine components, machines equipped with microprocessors. The microprocessor software to monitor the working state lasers, operating parameters from the panel LCD display. Once the laser operating parameters deviate from the permissible range set by the software, the microprocessor will automatically turn-off laser power. Flashing yellow light prompts alarm panel LCD prompts cause of the malfunction (non-human factors that can not be damaged laser). RF pre-distortion technology, ensuring the case of CSO-performance system for maximum CNR.
 
  FOT series Optical Transmitter products adopt the high linearity, optical isolation, the DFB, thermoelectric cooling DFB laser produced by ORTEL 、AOI、Fujitsu、Mitsubishi and other world-renowned semiconductor companies. It can provide high-quality images, digital or compressed digital signal long-distance transmission for cable television and telephone communications. Built-in RF driver amplifier and control circuitry to ensure the machine’s CNR, CTB, CSO target. Comprehensive and reliable optical circuits and laser output power stability Temperature stability of thermoelectric cooler control circuit to ensure optimal machine performance and long-life laser stability.
 
1.Quality: original system optimization control technology and RF pre-distortion technology ensure that the system can acquire the maximum CTB, CSO, and SBS targets in the case of excellent performance CNR.
 
2.Reliability: The 19 “1U standard rack, built-in high-performance dual switching power supply,it can work in the backup at 85 ∽ 265Vac City Network Voltage, MS-level automatic switching; chassis cooling automatic temperature control.
 
3.Intuitive: The laser is the most expensive machine components, machine equipped with microprocessor monitors the working state of the laser, the panel LCD window displays the operating parameters. Once the laser operating parameters deviate from the permissible range set by the software, micro-processing will automatically turn off laser power, yellow light goes on to warn, the panel LCD prompts the cause of troubles.
 
4.Power plug: Aluminum structure using plug switching power supply, allows for heat dissipation and replacement. And dual power supply hot and cold backup.

How to choose EPON Equipment

by www.fiber-mart.com
OLT detail parameter
 
  How to choose a suitable FTTH EPON equipment,especially for EPON OLT,which is a quite headache purchasing problem in fiber optic projects and daily telecom application,for its set of complicate technical specification parameters.
 
This blog post is trying to list all kinds of EPON (OLT/ONU)series product technical specifications and standards in detail,which will mainly focus on those interesting parameters by our buyers. Today we mainly introduce the follows factors:
 
 Device parameters
 Performance and capability
 EPON Interface (downlink) index
 Ethernet optical/electrial (uplink) interface
 Debug interface (OAM)
  For better understanding full list of those technical specifications:such as device size,weight,operating environment and power parameter etc,we pick up a OLT device from FOT(Fiber Optic Telecom) EPON Product line,as an example/reference,in this whole post.
 
  Here is introducing a high volume OLT device,one of FOT EPON OLT family members-8040F. 
 
1.25Gbit/s EPON interface
  What is EPON interface?The EPON interface is the one interconnected between OLT and ONU,speed can reach to 1.25Gbit/s both in uplink and downlink directions.The table “EPON Ethernet optical interface”(below) introduces the interface technical indicators of FOT’s  OLT series in detail.
 
Ethernet optical interface
As we know,besides the downlink direction to ONU device via EPON interface,OLT also have another direction,uplink to local Telecom vendor’s network,like ” city Metro IP Network”.This Ethernet optical interface and the following Ethernet electrical interface belong to the OLT’s uplink direction category.
 
 Instruction:Ethernet optical interface indicator is decided by optical module. Above indicators only for reference.
 
After showing those  six “Performance,Capability and Interface parameters indicator” tables above,hoping it helps our readers to build a  brief structure & profile of EPON equipment,especially for OLT device.So next time,before decide how to choose a FTTH EPON and related product,we could read this “structure & profile” in mind.

10G? XFP? Fiber Optic Transceiver Module

by www.fiber-mart.com
10G? XFP?
  The XFP (10 Gigabit Small Form Factor Pluggable) is a standard for transceivers for high-speed computer network and telecommunication links that use optical fiber. It was defined by an industry group in 2002, along with its interface to other electrical components, which is called XFI.
 
XFP’s Applications
10GBASE-LR/LW 10G Ethernet
1200-SM-LL-L 10G Fibre Channel
 XFP modules are hot-swappable and protocol-independent. They typically operate at near-infrared wavelengths (colors) of 850 nm, 1310 nm or 1550 nm. Principal applications include 10 Gigabit Ethernet, 10 Gbit/s Fibre Channel, synchronous optical networking (SONET) at OC-192 rates, synchronous optical networking STM-64, 10 Gbit/s Optical Transport Network (OTN) OTU-2, and parallel optics links. They can operate over a single wavelength or use dense wavelength-division multiplexing techniques. They include digital diagnostics that provide management that were added to the SFF-8472 standard. XFP modules use an LC fiber connector type to achieve higher density.
 
XFP’s Standard
  The XFP specification was developed by the XFP Multi Source Agreement Group. It is an informal agreement of an industry group, not officially endorsed by any standards body. The first preliminary specification was published on March 27, 2002. The first public release was on July 19, 2002. It was adopted on March 3, 2003, and updated with minor updates through August 31, 2005. The chair of the XFP group was Robert Snively of Brocade Communications Systems, and technical editor was Ali Ghiasi of Broadcom. The organization’s web site was maintained until 2009.
 
Description:
  (Make FOT’s FX-3110G-ERC as an example) Small Form Factor 10Gb/s (XFP) transceivers are compliant with the current XFP Multi-Source Agreement (MSA) Specification. They comply with 10-Gigabit Ethernet 10GBASE-LR/LW per IEEE 802.3ae and 10G Fibre Channel 1200-SM-LL-L. Digital diagnostics functions are available via a 2-wire serial interface, as specified in the XFP MSA.
 
Features:
Supports 9.95Gb/s to 10.5Gb/s bit rates
Hot-pluggable XFP footprint
Maximum link length of 40Km on SMF
Uncooled 1310nm DFB laser.
Duplex LC connector
Power dissipation <2.5W
No Reference Clock required
Built-in digital diagnostic functions
Temperature range -5°C to 70°C
Very low EMI and excellent ESD protection
Fully compliant to XFP MSA Rev.4.5
RoHS Compliant Part

2019年3月19日星期二

What Makes Fiber Optic Cables Future Proof?

by www.fiber-mart.com
Internet connectivity over an optical cord has become a precious standard for fast and high-quality data transmission. This technology is relatively new. This new nature of it can leave some in a dilemma. Some would even be unwilling to invest in it. Some would still prefer go old school and use convention network cables.
 
Over the years, with the technical progress, even conventional cable has risen to new horizons. But, which technology is better? Both copper and glass or optical cords have their benefits. Both have unique features. If something is better for others does not necessarily make it better for you. So, the right question to ask is which means would suit your business?
 
Fiber Optics Cable
The conventional copper wires transmit data via electricity. Fiber wire relies on light. It does not transmit data through the flow of electrons. This enables much faster internet connection. In fact, it also enables handling of a higher bandwidth. Sometimes, even during the peak demand, the performance of fiber wire stands out.
 
The cost of optical deployment has seen a dramatic reduction recently. Moreover, the fiber optic cable is future proof. This gives it an edge over the use of copper cables. It surely has a better prospect in the world market. Let us compare fiber and copper on these five determinants to decide which one is better and suits your purpose.
 
Cost
As mentioned above, the cost of fiber components has seen a decrease recently. Once, the cost of optical cord was twice that of a copper wire. Now the cost difference is minimal. In fact, if we consider the overall cost, copper cable can get costlier. This is if we consider the cost of wiring closet. This includes cost of uninterrupted power source, data ground and HAVC (Hybrid Automatic Voltage Control). Overall, an all fiber LAN is more cost efficient than a copper-based network.
 
Bandwidth
Copper is sufficient for voice signals. Even though it has a limited bandwidth of up to 60Gbps. Fiber cords are capable to provide 1000 times as much bandwidth as copper. It can also travel for a longer distance in lesser time. In simple terms, a 500-meter fiber wire can transmit 1GHz. Whereas, a twisted pair copper wire (Cat 6) can transmit 500Mhz just up to 100 meters. Moreover, the signal loss is negligible in an optical cable. Copper has higher losses at higher frequencies. It is also noisy.
 
Transmission Speed & Distance
This is literally the battle between photons and electrons! Photons do not achieve 100% efficiency in achieving the speed of light. But, even with 31% slow speed, it is much faster than the speed of electrons. You cannot overlook the significant difference which exists between fiber and copper. Moreover, copper wires also have the limitation of 100 meters. This is not the case with fiber cables. In optics, the distance can range from 550 meters for 10 Gbps single mode and up to 40 Kms for multi-mode!
 
Reliability
Fiber optics is not susceptible to damages from the surrounding environment. Copper has the trait of losing quality over certain distance under conditions. In fact, if we use a fiber optic cable over the same distance, under the same condition, it would provide you reliable data transmission. Moreover, fiber is immune to environmental and climatic factors. Temperature variation or any electromagnetic variation will not tarnish its performance. Copper is sensitive to these factors. You can deploy fiber optic cables near industrial equipment without worry. Likewise, you can also lay down fiber into deep oceans.
 
Security
One can trap the electrical signals from the copper cable. In addition, it also radiates signals. If someone traps the signals, the entire system can fail. On damages, it gets difficult to identify the leakages. In case of a fiber wire, detection of a broken wire is easier. This is because several monitoring techniques are in practice for detecting its flaws. Copper wire can cause a short circuit which can even result in a fire.
 
Conclusion
The usage of fiber cable with its ever reducing cost and other advantages is making it future proof. Increase in bandwidth, ridiculous increase in transmission speed and many more features make it better and reliable medium for networking. It is one of the most significant mediums for innovative installations and upgrades.

Troubleshoot Fiber Optics with the Right Optical Test Equipment

by www.fiber-mart.com
Fiber optic components, cable plants and the telecommunication systems that use them can be complex. They are comprised of fiber, connectors, splices, LED lights, laser sources, detectors and receivers—all forming an inter-connected tapestry of technology, each dependent on the next to function properly.
 
When one of the elements fails—when light escapes from one component—failure of the entire system can follow. A single element failure can wreak havoc on even the most well-thought-out network, as well as the buildings, businesses and organizations that network supports. This is why having the right optical testing equipment is so important for efficiently and effectively troubleshooting fiber optics.
 
Tools for Troubleshooting Fiber Optics
Here's a look at some of the essential tools you'll need when inspecting fiber optic cable for the myriad causes of system failure, including dust, oils and water blocking gel which can cause end-face contamination; scratches, pits, cracks and chips that can cause poor termination; or mated contamination and other issues that can arise:
 
The Optical Inspection Microscope—an optical inspection microscope with a 100 by 200 video scope should show you everything you need to see.
 
The Source and Power Meter—knowing with precision where the power is coming from—if it’s coming at all—is critical to troubleshooting fiber optics.
 
Reference Test Cables—make sure your test cables are compatible with the cables you’ll be testing, and don’t forget mating adaptors.
 
Fiber Tracer or Visual Fault Locator—either of these tools will allow you to visually check the continuity of the current and ensure that each of the connections is correct.
 
Cleaning Materials—Be sure to have a sufficient supply of dry cleaning kits, lint-free wipes and pure alcohol so you can clean and dry any components that have become dirty.
 
The ODTR* with Launch and Receive Cables—these are especially useful for jobs that require you to work outdoors or to test long cables (more than 250 meters/800 feet) or cable plants with splices.
 
These tools allow for basic inspection and cleaning, troubleshooting, verification, certification and even advanced OTDR analysis, all of which is achieved through visual tracing, visual fault location, inspection by microscope and the reversal of flow.
 
For more on optical test equipment, be sure to check out fiber-mart' full line of optical test equipment.

WANT TO ACHIEVE OPTIMAL FIBER INSTALLATION RESULTS?

by www.fiber-mart.com
If you’re a fiber optics cable installer or technician you know how important precision and comfort is due to the repetitious nature of the installation job. Although no special tools are required for fiber termination, a fiber installation termination kit is worth thinking about as it comes with all the specialized tools you need to prepare the fiber correctly, while also providing a stable work surface so that you get the best installation results possible.
 
Although fiber optic strands are 10X stronger than steel, the strands are about 2.5 times the thickness of a single human hair making fiber termination a somewhat delicate operation! Especially when compared to let’s say a single copper conductor on a CAT6 cable, which is relatively easy to terminate, right?
 
Well, the good news is that since fiber optic technology was introduced in the late 1970s, many new connector styles have been developed and each design is meant to offer better, faster performance and cheaper termination.
 
The latest Fiber FX Brilliance Universal Connectors by Belden feature a no-epoxy, no-polish, no-crimp design making fiber optic termination quicker, easier and cost-effective.
 
Using these connectors for LC, ST, SC adapters becomes even easier when you get a full array of termination tools, instructions and a comfortable, spacious pouch to carry your gear to any fiber termination site you need to go to. That’s where the FX Brilliance Universal Installation Kit by Belden comes in.
 
The Belden AX104270 Field Installation Kit has all the installation tools you need for error-free termination. It includes:
 
Tool Pouch and Handle
SC, LC,ST Adapters
VFL Patch Cords
Field Cleaver
Waste Bottle
Safety Glasses
Strippers
Scissors
Tweezers
USB Key
Marker
VFL
Microscope
Installation Guide & Card
 
You can let go of the perception that fiber-optic cabling is too cumbersome to install or too expensive. Many people today from homeowners to network managers to technicians and system engineers are discovering that fiber optic cabling and technology are actually quite feasible, and with the right tools in hand, the job gets that much easier.

2019年3月10日星期日

Fiber Optics Sensors Provide Early Warning for Landslides

by www.fiber-mart.com
Fiber optic sensors could warn people of imminent landslides, potentially saving lives and reducing destruction.
 
A team at the Second University of Naples is developing sensor technology that could detect and monitor both large landslides and slow slope movements. The researchers hope to mitigate the effects of these major natural disasters, similar to the way hurricane tracking can prompt coastal evacuations.
 
Optical fiber sensors embedded in shallow trenches within slopes would detect small shifts in the soil, the researchers said. Landslides are always preceded by various types of pre-failure strains, they said.
 
While the magnitude of pre-failure strains depends on the rock or soil involved — ranging from fractured rock debris and pyroclastic flows to fine-grained soils — they are measurable. Electrical sensors have long been used for monitoring landslides, but that type of sensor can be easily damaged, the researchers said. Optical fiber is more robust, economical and sensitive.
 
“Distributed optical fiber sensors can act as a ‘nervous system’ of slopes by measuring the tensile strain of the soil they’re embedded within,” said professor Dr. Luigi Zeni.
 
The researchers are also combining several types of optical fiber sensors into a plastic tube that twists and moves under the forces of the pre-failure strains. This will allow them to monitor the movement and bending of the optical fiber remotely to determine if a landslide is imminent.
 
The use of fiber optic sensors “allows us to overcome some limitations of traditional inclinometers, because fiber-based ones have no moving parts and can withstand larger soil deformations,” Zeni said.
 
He added that such sensors can be used to cover several square kilometers and monitored continuously to pinpoint critical zones.
 
The team will present their research at Frontiers in Optics in Tucson, Ariz., next month.

Introduction of the Transients in Optical WDM Networks

by www.fiber-mart.com
A systems analysis continues to be completed to consider dynamical transient effects in the physical layer of an Optical WDM Network. The physical layer dynamics include effects on different time scales. Dynamics from the transmission signal impulses possess a scale of picoseconds. The timing recovery loops in the receivers be employed in the nanoseconds time scale. Optical packet switching in the future networks will have microsecond time scale. Growth and development of such optical networks is yet continuing. Most of the advanced development work in optical WDM networks is presently focused on circuit switching networks, where lightpath change events (for example wavelength add/drop or cross-connect configuration changes) happen on the time scale of seconds.
 
It is focused on the dynamics from the average transmission power associated with the gain dynamics in Optical Line Amplifiers (OLA). These dynamics may be triggered by the circuit switching events and have millisecond time scale primarily defined by the Amplified Spontaneous Emission (ASE) kinetics in Erbium-Doped Fiber Amplifiers (EDFAs). The transmission power dynamics will also be influenced by other active components of optical network, for example automatically tunable 100GHz DWDM, spectral power equalizers, or other light processing components. When it comes to these dynamics, a typical power of the lightpath transmission signal is recognized as. High bandwidth modulation from the signal, which actually consists of separate information carrying pulses, is mostly ignored.
 
14_nodes Ring WDMRing WDM networks implementing communication between two fixed points are very well established technology, in particular, for carrying SONET over the WDM. Such simple networks with fixed WDM lighpaths happen to be analyzed in many detail. Fairly detailed first principle models for transmission power dynamics exist for such networks. These models are implemented in industrial software allowing engineering design calculations and dynamical simulation of these networks. Such models could possibly have very high fidelity, but their setup, tuning (model parameter identification) and exhaustive simulations covering a variety of transmission regimes are potentially very labor intensive. Adding description of new network components to such model could need a major effort.
 
14_nodes Mesh WDM The problems with detailed first principle models is going to be greatly exacerbated for future Mesh WDM networks. The near future core optical networks will be transparent to wavelength signals on a physical layer. In such network, each wavelength signal travels through the optical core between electronic IP routers around the optical network edge using the information contents unchanged. The signal power is attenuated in the passive network elements and boosted by the optical amplifiers. The lightpaths is going to be dynamically provisioned by Optical Cross-Connects (OXCs), routers, or switches independently on the underlying protocol for data transmission. Such network is basically a circuit switched network. It might experience complex transient processes of the average transmission power for every wavelength signal at the event of the lightpath add, drop, or re-routing. A mix of the signal propagation delay and channel cross-coupling might result in the transmission power disturbances propagating across the network in closed loops and causing stamina oscillations. Such oscillations were observed experimentally. Additionally, the transmission power and amplifier gain transients could be excited by changes in the average signal power because of the network traffic burstliness. If for some period of time the wavelength channel bandwidth is not fully utilized, this could result in a loss of the average power (average temporal density of the transmitted information pulses).
 
First circuit switched optical networks are already being designed and deployed. Fraxel treatments develops rapidly for metro area and long term networks. Engineering design of circuit switched networks is complicated because performance has to be guaranteed for all possible combinations of the lightpaths. Further, as such networks develop and grow, they potentially need to combine heterogenous equipment from a variety of vendors. A system integrator (e.g., fiber-mart.com) of such network might be different from subsystems or component manufacturer. This creates a necessity of developing adequate means of transmission power dynamics calculations which are suitable for the circuit switched network business. Ideally, these methods should be modular, independent on the network complexity, and use specifications on the component/subsystem level.
 
fiber-mart.com has technical approach to systems analysis that’s to linearize the nonlinear system around a fixed regime, describe the nonlinearity like a model uncertainty, and apply robust analysis that guarantees stability and gratifaction conditions within the presence of the uncertainty. For a user of the approach, there is no need to understand the derivation and system analysis technicalities. The obtained results are very simple and relate performance to basic specifications of the network components. These specifications are somewhat not the same as those widely used in the industry, but could be defined from simple experimentation using the components and subsystems. The obtained specification requirements may be used in growth and development of optical amplifiers, equalizers, optical attenuators, other transmission signal conditioning devices, OADM Modules, OXCs, and any other optical network devices and subsystems influencing the transmission power.
 
fiber-mart.com specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Introduction of Fiber Optic Coupler with its Benefits & Classification

by www.fiber-mart.com
fiber optic coupler is an indispensable part of the world of electrical devices. Without these no signals would be transmitted or converted from inputs to outputs. This is the reason these are so important thereby this article discussed about these, introduction, classification and benefits in detail.
 
Fiber Optic Coupler is an optical cog that is capable of connecting single or multiple fiber ends in order to permit the broadcast of light waves in manifold paths. This optical device is also capable of coalescing two or more inputs into a single output while dividing a single input into two or more outputs. In comparison to a connector or a splice, the signals may be even more attenuated by FOC i.e. Fiber Optic Couplers; this is due to the division of input signal amongst the output ports.
 
Types of Fiber Optic Coupler
 
Fiber Optic Couplers are broadly classified into two, the active or passive devices. For the operation of active fiber coupler an external power source is required, conversely no power is needed when it comes to operate the passive fiber optic couplers.
 
Fiber Optic Couplers can be of different types for instance X couplers, PM Fiber Couplers, combiners, stars, splitters and trees etc. Let’s discuss the function of each of the type of the Fiber Optic Couplers:
 
Combiners: This type of Fiber Optic Coupler combines two signals and yields single output.
 
Splitters: These supply multiple (two) outputs by using the single optical signal. The splitters can be categorized into T couplers and Y couplers, with the former having an irregular power distribution and latter with equal power allocation.
 
Tree Couplers: The Tree couplers execute both the functions of combiners as well as splitters in just one device. This categorization is typically based upon the number of inputs and outputs ports. These are either single input with a multi-output or multi-input with a single output.
 
PM Coupler: This stands for Polarization Maintaining Fiber Coupler. It is a device which either coalesces the luminosity signals from two PM fibers into a one PM fiber, or splits the light rays from the input PM fiber into multiple output PM fibers. Its applications include PM fiber interferometers, signal monitoring in its systems, and also power sharing in polarization sensitive systems etc.
 
Star Coupler: The role of star coupler is to distribute power from the inputs to the outputs.
 
Benefits of Fiber Optical Couplers
 
There are several benefits of using fiber optic couplers. Such as:
 
Low excess loss,
High reliability,
High stability,
Dual operating window,
Low polarization dependent loss,
High directivity and Stumpy insertion loss.
The listed benefits of Fiber Optical Couplers make them ideal for many applications for instance community antenna networks, optical communication systems and fiber-to-home technology etc.