Opnext can make the claim because the first generation of Ciena’s (ex-Nortel) PM-QPSK 100G technology isn’t single-wavelength.

The trial conducted over a long-haul link with 10-Gbps and 40-Gbps mixed traffic ran from Uppsala to Olofström in Sweden and back for a total distance of 1700 km. This represents the longest un-regenerated real-time test announced to date, Opnext says.

Opnext says its plug-and-play technology enables carriers to upgrade their existing line systems to 100 Gbps without requiring any change to their existing networks. In addition, new systems using Opnext technology can eliminate the need for external dispersion compensation, which reduces cost, minimizes IP latency, and enables deployment over older installed fiber optic cable.

“100G modem performance is critical to help carriers meet the ever-increasing bandwidth demands from their customers,” said Mike Chan, president of the Opnext Subsystems business unit. “This trial represents the longest real-time 100G trial performed to date, moving the industry one step closer to the commercialization of 100G technology.”

In addition, the latter three companies, which founded the CFP MSA, have welcomed Avago Technologies as a new member. Other manufacturer companies interested in joining the CFP MSA are encouraged to contact an existing MSA representative, the companies say.

The purpose of the CFP MSA is to define a hot-pluggable optical transceiver form factor to enable 40-Gbps and 100-Gbps applications, including next-generation High Speed Ethernet (40 Gigabit Ethernet and 100 Gigabit Ethernet). The pluggable CFP transceivers are designed to support the ultra-high bandwidth requirements of data communications and telecommunications networks. (For more information, particularly the differences between the CFP and other high-speed transceiver MSAs

The Institute of Electrical and Electronics Engineers (IEEE) recently standardized 40-Gigabit Ethernet and 100-Gigabit Ethernet under the P802.3ba Task Force and is currently working to add new features to 40-Gigabit Ethernet in the P802.3bg Task Force. In addition to the existing 40-Gbps telecom standards, both the OIF and the ITU-T are working on standardizing SDH/OTN telecom interfaces for long-haul transmission of 100-Gigabit Ethernet.

Pluggable transceiver modules compliant to the CFP MSA will be used on these 40-Gbps and 100-Gbps interfaces, the companies predict. The CFP MSA is defining the specifications for a transceiver that will support multiple applications using the same form factor. These applications include various protocols (such as 40GbE, 100GbE, OC-768/STM-256, OTU3), media types (multimode and singlemode fiber optics), and link distances.

The CFP MSA leverages advanced thermal management, EMI management, and enhanced electrical signal integrity design to define the transceiver mechanical form factor, the optical connector, the 10×10-Gbps electrical connector with its pin assignments, the MDIO-based transceiver management interface, and the hardware required on the system host board.

Set for completion in 2010, CCL will be 33.3 km long with 29 stations. Its purpose is to cut traveling time by enabling commuters to bypass busy interchanges.

The primary goal of the Land Transport Authority of Singapore is to provide the population of around 4.5 million, plus its 10 million yearly visitors, with a safe, efficient, and comfortable means of public transportation.

On completion, the CCL is expected to carry around 500,000 commuters. It will also be used by a large volume of tourists, the numbers of which are anticipated to increase with the imminent opening of two new integrated (casino and theme park) resorts in the city.

With such a high passenger flow, the monitoring and management of crowd control is of paramount importance. The Singapore government is also dedicated to countering potential terrorist threats to the country across its infrastructure. To address these issues, an extensive surveillance system has been installed incorporating VOSCOM’s fiber optic Video equipment.

Singaporeans are extensive users of public transport and proud of their world-class system. CCL therefore requires state-of-the-art security equipment. Singapore Technologies Electronics, the system integrator for the surveillance project, chose VOSCOM as an integral supplier for the system.

VOSCOM will be responsible for providing the fiber optic transmission systems within each of the CCL stations. The units will relay the collected video, data, and alarm signals from the surveillance cameras to each of the station control rooms. The project involves the deployment of four-channel digital fiber optic video multiplexers, fiber optic transmitters and fiber optic receivers, which will connect the surveillance security system while maintaining high picture quality at all times.

For such a high-profile installation, the customer needed to have complete confidence in their suppliers. VOSCOM met this expectation through its reputation for product reliability and by demonstrating technical support and local knowledge.

The project also demanded short lead times for installation, which VOSCOM was able to meet as a result of close cooperation between its regional office and the factory.

Optical Zonu says key attributes of the new product include:

• operation from 20 MHz to 7 GHz
• high SFDR, which provides “excellent noise performance and high linearity”
• very stable gain
• flat frequency response
• extended temperature range of operation
• a rugged, simple, modular package.

Since the analog RF parameters of fiber optic transmission depend upon the operating temperature of the laser diode, transceivers such as the OZ1600 use a thermo-electric cooler (TEC) that locks the temperature of the laser at a constant level, stabilizing the laser wavelength, optical powerm, and relative intensity noise (RIN). The new transceiver operates over -20°C to +65°C with gain variation of less than 2 dB, the company asserts.

“These linear RF over fiber transceivers allow physical separation of RF systems components that cannot be achieved using coaxial cable or transmission lines,” said Soyola Baasan, director of sales at Optical Zonu. “They offer significant improvements in the transport of RF signals in their native format reliably over many optical networks and across a broad range of frequencies. Applications that benefit most from this technology include antenna “remoting,” satcom, GPS distribution, DAS, distributed emitter systems, timing and frequency signal transmission over optical fiber that requires low phase noise, WiMax, 4G LTE, or any other application that requires sending RF signals over optical fiber reliably and in very stable form despite ambient temperature variation.”

The standard optical connector is the SC/APC (FC/APC is also available) for low back reflection applications like analog video and long-haul digital data transmission. An optional multimode fiber version is also available.

The base OZ1600 unit is priced depending upon the specification of options and unit volume (contact the factory for details) and is available 6 to 8 weeks ARO.

“GPON growth in the first quarter was largely due to deployments in China,” said Tam Dell’Oro, president of Dell’Oro Group. “China Unicom and China Telecom are deploying both EPON and GPON. China Mobile, which was recently granted permission to deploy broadband and for which GPON is its preferred technology, also contributed to first quarter GPON growth. Other sizeable GPON shipments in the first quarter included those to Korea, Malaysia, Portugal, Singapore, Spain, the UAE, and the US.”

The report shows that Huawei maintained its lead for GPON revenue largely due to being a primary supplier in the China market. Next was Alcatel-Lucent and Voscom, which narrowed the gap with Huawei due to growth of its ONT shipments to North America and EMEA.

Rounding out the top four were Motorola followed closely by Ericsson, which doubled its share mainly due to growth in GPON shipments to China.

The new VOS-DC400 series utilizes digitally encoded technology and can implement multimode video input via one single mode fiber. A single fiber link can transmit up to 16 video channels, and the remote node video input module can transmit one to eight video channels. Every node can be configured for multichannel audio, RS-422/RS-485/RS-232 data, contact closures and 10M/100M Ethernet. It has provides significant savings on fiber infrastructure costs.

The system can be configured as dual optical redundancy transmission, which provides a much more reliable signal transmission when there is cable break.  It also support up to 128 channels of video transmission by incorporating CWDM technology. Two SFP ports and a plug-and-play design ensure ease of installation with no optical adjustments required. The central receiver modules can be plugged in a 19″ 4U dual power chassis. The VOS-Mview Network Management System provides easy remote monitoring and management.

The drop and insert fiber link is a field proven solution for the borders and perimeters, highway and ITS, airports and large industrial site projects. Since 2003, VOSCOM TECHNOLOGIES’s VOS-DC system has secured more than 295 transportation projects, and the new innovative VOS-DC400 system is set to help more system integrators in providing customized fiber transmission solution. “VOSCOM TECHNOLOGIES provides more than just quality equipment, it has rich experience in developing project-specific fiber solutions for every surveillance situation, “said Mr. Danny Chan, the marketing director of VOSCOM TECHNOLOGIES. “ We have seen great interest in this upgraded system among installers and distributors during the IFSEC2010, and it is also very encouraging that many of the system integrators and consultant have interest in integrating our system into their solutions.”

More information, please find here: http://www.voscom.com/

This example illustrates the main features of any fibre optic converter system, which are as follows:

1. The fibre optic link and its associated terminal equipment fit between the camera and the associated monitor/controller and provide a transparent signal path i.e. the camera and controller do not know that the signals have been transmitted over fibre.

2. The camera output is a 1V peak to peak composite video signal.

3. Movable cameras have a telemetry receiver is mounted near to the camera movement mechanism. This telemetry receiver connects to the system controller to provide control of the camera pan/tilt and zoom PTZ functions.

4. At the control end of the link camera selection and movement is looked after by the system controller and video signal outputs from the controller are displayed on a local monitor(s).

5. Electrical to optical and optical to electrical converters provides the interfaces to the optical fibre transmission fibre.

6. At the camera end of the link the E/O converter is usually a single channel unit packaged in a small enclosure which can be conveniently mounted near to the camera or telemetry receiver. These E/O converters are not usually environmentally sealed and so need to be protected from the elements often mounting them in the telemetry receiver
enclosure. In their most cost effective form a PTZ E/O converter will use two multimode fibres to give a uni-directional video connection plus a bi-directional control data channel.

7. As an alternative these control and video link functions can be carried over a single fibre using optical transmission at two wavelengths, WDM – wavelength division multiplexing. These WDM links are more expensive than single wavelength links but they do save on fibre usage and they also can make the best use of a previously installed
fibre infrastructure.

8. The E/O converter data interface must be compatible with that used by the system controller; these are often non-standard.

9. Fixed cameras can use a miniature E/O transmitter, which can connect directly to the camera BNC signal output. This link requires only one fibre.

10. The camera end E/O converter is connected to the transmission fibre through a patch box. This patch box provides a point of termination for the transmission cable and so prevents strain and wear and tear being placed on the transmission cable when installing, servicing or moving the terminal equipment. Optical connections between the
E/O converter and the patch box are made with duplex patchleads (which are short fibre cable lengths terminated at each end with an optical connector). The patch box will only be a relatively small enclosure because it will only need to provide connectivity for a few fibre cores.

11. At the control room end of the link fibres from a large number of cameras will be concentrated. Equipment must therefore be packaged accordingly and most often this means the use of 19” rack mount units. E/O converters are manufactured in modular card format, which enables multiple video channels to be accommodated in a 19” cage.
Typically one 3 U high rack can accept plug-in E/O converters for up to 30 video only channels or 10 video/data channels (or a mixture of both).

12. The fibre transmission cables are also handled in 19” rack enclosures because now we will be organising many fibre cores. These enclosures are called patch panels and they again provide a physical buffer between the transmission cable and the terminal equipment. Here the cable will be bought into the rear of the patch panel via a compression gland and the fibre cores will be broken out into the secondary coated cores. These cores will then be terminated with connectors, which are then connected into in-line adaptors mounted through the front bulkhead of the patch panel enclosure. This termination may either be carried out by the direct attachment of connectors to the fibre tails or factory terminated connectors tails will be spliced to the transmission fibre cores. If splices are used then the splice enclosures will be mounted in clips on the patch panel base. Patchleads then connect the patch panel bulkhead connections to the E/O converter optical connections. Copper leads then complete the connections to the system
controller and monitors.

As part of the cable installation the installer will have measured the installed cable loss, a function of position using a piece of test equipment called an OTDR (Optical Time Domain Reflectometer). This measurement serves to finger print the system and provides a point of reference for future system maintenance. It also provides the value of the end to end loss of each optical fibre used. The total loss must not exceed the optical margin specified by the equipment manufacturer, otherwise the transmitted picture quality may be impaired. In a correctly installed multimode system link lengths of 4 km for 850nm products and 8 km for 1300nm products are readily achieved.

The following illustration shows the differences between these two types of multimode fibers on refractive index profile and how they guide light.

Fiber Optic Transmission in a Step-Index Multimode Fiber and a Graded-Index Multimode Fiber

Step-index multimode fibers are mostly used for imaging and illumination. Graded-index multimode fibers are used for data communications and networks carrying signals moderate distances – typically no more than a couple of kilometers

Modal-Dispersion and Limit on Step-Index Multimode Fibers’ Bandwidth

Take a look at the illustration for a step-index multimode fiber. Rays of light enter the fiber with different angles to the fiber axis, up to the fiber’s acceptance angle (numerical aperture). Rays that enter with a shallower angle travel by a more direct path, and arrive sooner than those enter at steeper angles (which reflect many more times off the core/cladding boundaries as they travel the length of the fiber). The arrival of different modes of the light at different times is called Modal Dispersion.

Index Profile Difference Between Step-Index Multimode Fiber and Graded-Index Multimode Fiber

Light Transmission in a Step-Index Multimode Fiber and a Graded-Index Multimode Fiber

Step-index multimode fibers are mostly used for imaging and illumination. Graded-index multimode fibers are used for data communications and networks carrying signals moderate distances – typically no more than a couple of kilometers

Modal-Dispersion and Limit on Step-Index Multimode Fibers’ Bandwidth

Take a look at the illustration for a step-index multimode fiber. Rays of light enter the fiber with different angles to the fiber axis, up to the fiber’s acceptance angle (numerical aperture). Rays that enter with a shallower angle travel by a more direct path, and arrive sooner than those enter at steeper angles (which reflect many more times off the core/cladding boundaries as they travel the length of the fiber). The arrival of different modes of the light at different times is called Modal Dispersion.

Modal Dispersion is also called modal distortion, multimode dispersion, intermodal distortion, intermodal dispersion, and intermodal delay distortion.

Digital communications use light pulse to transmit signal down the length of the fiber, as we explain in the fiber optic network tutorial. Modal dispersion causes pulses to spread out as they travel along the fiber, the more modes the fiber transmits, the more pulses spread out. This significantly limits the bandwidth of step-index multimode fibers.

For example, a typical step-index multimode fiber with a 50 µm core would be limited to approximately 20 MHz for a one kilometer length, in other words, a bandwidth of 20 MHz·km.

Graded-Index Multimode Fibers Solves the Problem of Modal Dispersion

Graded-index fiber’s refractive index decreases gradually away from its center, finally dropping to the same value as the cladding at the edge of the core. The change in refractive index causes refraction, instead of total internal reflection, which bends light rays back toward the fiber axis as they pass through layers with lower refractive index. No total internal reflection happens because refraction bends light rays back into the fiber axis before they reach the cladding boundary.

Different light modes in a graded-index multimode fiber still follow different lengths along the fiber, as in step-index multimode fiber.  However their speeds differ because the speed of guided light changes with fiber core’s refractive index.

So the farther the light goes from the center of the fiber, the faster its speed. So the speed difference compensate for the longer paths followed by the light rays that go farthest from the center of the fiber. This equalizing of transit times of different modes greatly reduces modal dispersion.

The bandwidth of a typical off-the-shelf graded-index multimode fiber with a 50 µm core may approach 1 GHz·km or more. Multimode graded-index fibers having bandwidths approaching 3 GHz·km have been produced.

But please note that modal dispersion may be considerably reduced, but never completely eliminated.

Laser Optimized Multimode (Multi Mode) Optical Fibers from Corning

The most common type of single mode fiber has a base diameter of 8-10 mu m and is designed for use in the near infrared (the most common are designed 1550nm and 1310nm). Please note that the structure of method depends on the wavelength of light used, so that these fibers actually a few extra modes to wavelengths visible support. multi-mode fiber, compared with core diameters as small as 50um multimode and as large as a hundred microns.

The image below shows the structure of a single mode optical fiber.

What Are the Conditions for Single Mode Transmission?

To calculate the number of modes N_m in a step-index fiber, N_m can be simplified as:

Where
D is core diameter of the fiber
λ is the operating wavelength
n_f is refractive index of the fiber core
n_c is refractive index of the fiber cladding

Reducing the core diameter sufficiently can limit transmission to a single mode. The following formula defines the maximum core diameter, D, which limits transmission to a single mode at a particular wavelength, λ :
If the core is any larger, the fiber can carry two modes.

Mode field diameter (MFD)

The core diameter typical communication single-mode fibers from 8 ~ 10um for the operation of 1.31um 1.5um wavelength. Fibre with a base diameter of less than about ten times the wavelength of light propagation can be modeled using geometric optics, as in explaining the multimode fiber with step index have. Instead, they must be analyzed, reduced by solving Maxwell’s equations of the electromagnetic wave equation as an electromagnetic structure.

Thus, although the fiber cladding, the light confined in the heart of the fiber, the light penetrates into the mantle, despite the fact that it undergoes total internal reflection nominally. This is done both in mono mode and multimode fibers, but the phenomenon is important in single mode optical fiber.

be used for a Gaussian distribution (laser in the Gaussian distribution of communication) in a single mode fiber, the mode field diameter (MFD) as the point where the intensities of electric and magnetic fields up to 1 / e is defined reduce their peak values, the diameter of the power 1/e2 (0135) of the peak power (because the force is proportional to the square of the field strength) is reduced. For singlemode fibers, the peak in the middle of the nucleus.

Mode field diameter is slightly larger than the base diameter, as shown in the following figure.

References on how to measure mode field diameter for a single mode fiber

• EIA/TIA-455-191 (FOTP-191), Measurement of Mode-Field Diameter of Single-Mode Optical Fiber.
• http://www.corning.com/docs/opticalfiber/mm16_08-01.pdf Corning’s paper on how to measure mode field diameter for a single mode fiber
• Measurement of Mode-Field Diameter of Single-Mode Optical Fiber, Fiberoptic Test Procedure FOTP-191, Telecommunications Industry Association, Standards and Technology Department, 2500 Wilson Blvd., Suite 300, Arlington, VA, 22201 (1998).
• Measurement of the Effective Area of Single-Mode Optical Fiber, Fiberoptic Test Procedure FOTP-132, Telecommunications Industry Association, Standards and Technology Department 2500 Wilson Blvd., Suite 300, Arlington, VA, 22201 (1998).

Advantages of single-mode fiber

dispersion single mode fiber modal, modal noise and other effects that come with multiple gears, single-mode fiber capable of carrying signals at much higher rates than multimode fiber. You are span standard option for high data rates and long distance (over a few kilometers), the laser diode based telecommunications transmission technology used fiber.

Disadvantages of singlemode fiber

Since the heart of the single-mode fiber is much smaller than the multimode fiber optic core, the light coupling single mode optical fiber requires much tighter tolerances than the light coupling into the veins over multimode fiber. However, these tolerances were more available.

singlemode fiber optic components and devices are also more expensive than their counterparts multimode fiber to multi-mode is widely used in systems where low cost connections and distances and transmission speeds must be taken are used modestly.

Single Mode Optical Fibers from Corning

IP networks and opportunities for content distribution on Cat-5 and other simple, low cost cabling, have been much attention in recent years. However, more and more users and developers and integrators that are used these days to decide that the benefits of fiber can not simply be denied.

And even as businesses in the commercial, industrial, governmental and educational surges, watching the players with the anticipation of growth much higher than could follow if the slowdown in the development of the fiber to the home (FTTH) buildout gathers steam this year as expected by many.

Verizon has a plan for $20 billion spent on stringing fiber to six million customers in 2006 announced the land cost. French Telecom, Alcatel continues its acquisition of Lucent, is a dynamic player in FTTH. Telecoms see a greater capacity of new fiber as the key to the so-called “triple play”, the ability to offer voice, data, video and consumer on a connection.

Defenders of fibers, perhaps the future growth similar to past experience through the projection and display markets LCD, plasma and rear-projection TV Mainstream a sudden jump of thousands of units sold per year, tens of millions.

But few companies in the fiber to wait. In fact, according to Fred Scott, Vice-President, Broadcasting and fiber products for GE Pro AV, while many other market segments are booming in the here and now, FTTH is just testing the waters.

Scott gives the example monitoring. “There is an overwhelming need to begin now to see what happens everywhere in the subway stations, bus terminals,” he said. “All these monitoring devices in many cases to a central area of a fiber run-Feed. ”

military users are also committed to large-scale networks of optical fiber, according to Scott. “There are a number of institutions that have pulled all its control rooms on the optical fiber,” he said. “The number one reason for this is no one to monitor or tap into the signal content . Government, research, and others must be supplied with fiber insulation in the region, or a rack of equipment to another. ”

Don Hosmer, National Sales Manager at VOSCOM, also refers to security as a powerful attraction of the fiber. “We can not look at the data onto the fiber, without physically touching the wire,” he commented.

The quality problems are often just as important, and account for the rise in another area of CITES Hosmer strong growth: medical imaging. “Everything is moving dramatically to high definition,” said Hosmer, while applications such as video-endoscopy, surgical video, and telemedicine.

“] [In these applications, you need to maintain color accuracy, and if you compress the video you may have to be a problem,” Hosmer said, adding that uncompressed video data via fiber travel.

A fundamental decision on the users of each network is whether the network components wired together or connect them with a strategy based on the Internet. For direct connection of sites, premises and facilities, the choice often comes down to coaxial cable or fiber optics. Many organizations will have many other activities that may interfere with electronic signals over networks of coaxial or twisted pair, but not in the fiber.

“Fiber gives a solution for a variety of institutions that have problems when you try to perform any type of copper solution,” said Scott. “Committees Dimmer electricity, lighting, might affect an entire copper plant, but if you do it on the fiberglass, it is no problem.”

As the fiber makes its way into the business more and more, technology can also misunderstood Ace in the Hole. Hosmer recalls: “In the dot-com era, the people of telecommunications has attracted lots and lots of fiber.” The “dark” fiber was left, like many of his owner went bankrupt, he said, but TODAY ‘Today, “it is always there, ready to be lit.