Optical Fiber In-line Polarizer & its Fine Features

The significance and value of Optical fibers don’t need any explanations or specifications in the world of electronics and technology. These devices are no doubt the tiny part but are equally important as well as requisite for the effective / efficient working of the machinery and electronic. When we talk about optical fiber In-line polarizer these are the cogs which can never be overlooked.
Optical Fiber In-line Polarizer
Low cost optical fiber In-line polarizer is the device to convert unpolarized light into linearly polarized light. It encompasses both, input as well as output as one input of single mode fiber and one output with polarization maintaining fiber. It can easily be connected conveniently into the optical systems through pigtailed input / output connectors.

Now let’s discuss the fine features of In-line Polarizer:

• Low insertion loss: in telecommunications, the loss of signal power coming from the insertion of a device into the optical fiber is generally referred to as insertion cost. The insertion cost of the In-line polarization is stumpy and quite lesser than the other similar devices.
• High extinction ratio: the polarizer especially, the In-line polarizer usually have the high extinction ratio i.e. the ratio of the two optical power levels of a digital signal produced by an ocular source.
• High return loss: The optical fiber polarizer generates high return loss i.e. the loss of power in the signal reflected / returned by a discontinuity in a broadcast line or ocular fiber.
• Compactness and light weight: Yet another beneficial feature of an In-line Polarizer is that it is quite compact as well as light weighted. This helps in the placement and execution of the appliance. Its light weight helps it work easily and effortlessly.
• High stability and reliability: In-line polarizer is always recommended as it is quite stable as well as reliable. Unlike all other types of polarizers, the in-line polarizer has higher stability. This is the reason why companies and industries trust these.

Beyond all, the optical fiber In-line polarizer is available in market at low costs. There are several organizations which offer and sell the high quality optical fiber solutions at competitive prices and ensure you an effective as well as a durable working.
So, whenever you seek the high quality optical fiber In-line Polarizer, or decide to buy them, make sure you choose a copper-bottomed company to get the best products and high quality services as well as high class solutions at competitive prices!
DK Photonics – www.dkphotonics.com  Service to the factories, equipment manufacturers, operators and institutes who work for optical passive components, fiber communication, fiber sensing and high power laser applications, such as 1064nm High Power Isolator,1064nm High Power Circulator, Multimode Pump Combiner, Pump and Signal Combiner, Pump and PM Signal Combiner, Cladding Power Stripper, Polarization  Maintaining Optical Circulator, Polarization Maintaining Optical Isolator, Polarization Beam Combiner/Splitter, PM Filter WDM, Polarization Maintaining Filter Coupler, Polarization Maintaining Tap  Coupler, Polarization Maintaining Fused Coupler, Polarization Maintaining Fused WDM, In-line Polarizer.

Learning the Different Coating Stripping Methods

The cladding power stripper also referred to as the multimode optical power stripper is designed for amplifier applications and high power fiber laser. It is an ideal device  for ASE, residual pump power stripping, core modes that have escaped from double cladding fibers inner cladding while ensuring preservation of single power minimal degradation and beam quality (M2). Single power that is reflected into the inner cladding may also be stripped out too.  The handling capability of the stripping power goes to 800W or at times may be even higher

Stripping the Coating

The fibers that most reputable companies supply all come with a standard  acrylate single layer coating or, in some such as the high power products, a coating that is high temperature enduring. In comparison to dual layer coatings, the coatings that are single layer are more brittle and smooth. The coating can be removed readily using the conventional tools for fiber stripping such as the Fitel S-210 Clauss or CFS-1 for 125 μm cladding diameter fiber or for larger cladding diameters the Clauss No Nik stripper is used. For fibers whose outer diameter is non-standard, it is recommended that an adjustable stripper is used.  Thermal strippers such as those that are attached to the Schleuniger FiberStrip 7030 or the Vytran FFS-2000 can be used for all fiber in a safe way.

Alternatively, chemical stripping of fibers can be done using an appropriate solvent. For example, the coating can be exposed for one minute to sulfuric acid at 120°C sulfuric acid. Before the fiber is dipped into the liquid, the tip should be sealed with a drop of glue of 2 mm in diameter or through the end fiber hole collapsing using a fusion splicer.  It is worth noting that most glue types are dissolved in this acid, but epoxies that are two-component such as the Epotek ND353 tends to dissolve in a slower manner than the coating.

It is also possible to obtain chemical stripping through application on the fiber tip, of paint stripper. The paint stripper is usually in the form of a gel so as to reduce the occurrence of out-gassing and can be applied easily using a small brush. After a minute or so, the coating becomes soft and is removed easily using a lens tissue. It is worth noting that paint stripper typically contains dichloromethane (CH2Cl2) and as such there may be restrictions by local regulations to use it. For lower quality and faster stripping, another option would be to use a normal cigarette lighter to burn the coating off. However, the fiber may end up becoming brittle hence not the best choice for stripping.

Optical Fiber In-line Polarizer & its Fine Features

The significance and value of Optical fibers don’t need any explanations or specifications in the world of electronics and technology. These devices are no doubt the tiny part but are equally important as well as requisite for the effective / efficient working of the machinery and electronic. When we talk about optical fiber In-line polarizer these are the cogs which can never be overlooked.

Low cost optical fiber In-line polarizer is the device to convert unpolarized light into linearly polarized light. It encompasses both, input as well as output as one input of single mode fiber and one output with polarization maintaining fiber. It can easily be connected conveniently into the optical systems through pigtailed input / output connectors.

Now let’s discuss the fine features of In-line Polarizer:

• Low insertion loss: in telecommunications, the loss of signal power coming from the insertion of a device into the optical fiber is generally referred to as insertion cost. The insertion cost of the In-line polarization is stumpy and quite lesser than the other similar devices.

• High extinction ratio: the polarizer especially, the In-line polarizer usually have the high extinction ratio i.e. the ratio of the two optical power levels of a digital signal produced by an ocular source.

• High return loss: The optical fiber polarizer generates high return loss i.e. the loss of power in the signal reflected / returned by a discontinuity in a broadcast line or ocular fiber.

• Compactness and light weight: Yet another beneficial feature of an In-line Polarizer is that it is quite compact as well as light weighted. This helps in the placement and execution of the appliance. Its light weight helps it work easily and effortlessly.

• High stability and reliability: In-line polarizer is always recommended as it is quite stable as well as reliable. Unlike all other types of polarizers, the in-line polarizer has higher stability. This is the reason why companies and industries trust these.

 Beyond all, the optical fiber In-line polarizer is available in market at low costs. There are several organizations which offer and sell the high quality optical fiber solutions at competitive prices and ensure you an effective as well as a durable working.

So, whenever you seek the high quality optical fiber In-line Polarizer, or decide to buy them, make sure you choose a copper-bottomed company to get the best products and high quality services as well as high class solutions at competitive prices!

The significance and value of Optical fibers don’t need any explanations or specifications in the world of electronics and technology. These devices are no doubt the tiny part but are equally important as well as requisite for the effective / efficient working of the machinery and electronic. When we talk about optical fiber In-line polarizer these are the cogs which can never be overlooked.

Optical Fiber In-line Polarizer

Low cost optical fiber In-line polarizer is the device to convert unpolarized light into linearly polarized light. It encompasses both, input as well as output as one input of single mode fiber and one output with polarization maintaining fiber. It can easily be connected conveniently into the optical systems through pigtailed input / output connectors.

Now let’s discuss the fine features of In-line Polarizer:

• Low insertion loss: in telecommunications, the loss of signal power coming from the insertion of a device into the optical fiber is generally referred to as insertion cost. The insertion cost of the In-line polarization is stumpy and quite lesser than the other similar devices.

• High extinction ratio: the polarizer especially, the In-line polarizer usually have the high extinction ratio i.e. the ratio of the two optical power levels of a digital signal produced by an ocular source.

• High return loss: The optical fiber polarizer generates high return loss i.e. the loss of power in the signal reflected / returned by a discontinuity in a broadcast line or ocular fiber.

• Compactness and light weight: Yet another beneficial feature of an In-line Polarizer is that it is quite compact as well as light weighted. This helps in the placement and execution of the appliance. Its light weight helps it work easily and effortlessly.

• High stability and reliability: In-line polarizer is always recommended as it is quite stable as well as reliable. Unlike all other types of polarizers, the in-line polarizer has higher stability. This is the reason why companies and industries trust these.

 Beyond all, the optical fiber In-line polarizer is available in market at low costs. There are several organizations which offer and sell the high quality optical fiber solutions at competitive prices and ensure you an effective as well as a durable working.

So, whenever you seek the high quality optical fiber In-line Polarizer, or decide to buy them, make sure you choose a copper-bottomed company to get the best products and high quality services as well as high class solutions at competitive prices!

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Fiber Media Converters in Private DatacomMarket Forecast (March 2014)

According to ElectroniCast, the global use of fiber media converters in private datacom networks is expected to reach $1.29 billion in 2014…

Aptos, CA (USA) – March 20, 2014 --ElectroniCast Consultants, a leader in fiber optic market research, announced the release of a new market analysis of the worldwide use of fiber optic / Fiber media converters in private data communications.  A fiber media converter is a networking device that makes it possible to connect two dissimilar media types such as copper with fiber optic cabling, as well as (different) fiber-to-fiber (F2F), such as multimode to single mode optical fiber.

The worldwide value for selected fiber media converters used in private datacom networks reached $1.07 billion in 2013. The consumption value is forecast increase with strongly rising quantity growth partially offset by declining average prices.

The EMEA and the APAC regions are forecast for double-digit consumption value growth during the timeline covered in this study (2013-2018); however, the American region’s growth is forecast to “flatten” and eventually turn to negative.  The worldwide use of private datacom fiber media converters, which are specified in the ElectroniCast market study, is forecast to peak at $1.646 billion in 2017, before slipping to $1.628 billion in 2018.

“The fiber media converters researched in this market study are typically used within an existing Private Enterprise Data Centers (DCs) and Local Area Networks (LANs), as well as other non-public data communication links. They are often used to connect newer 100-Mbps, Gigabit Ethernet, 10G, or other equipment in existing networks, which are generally (copper-based) 10BASE-T, 100BASE-T, or a mixture of both,” stated Stephen Montgomery, Director of the Fiber Optics Components group at ElectroniCast Consultants.

“Several factors make the conversion from copper to optical fiber a good choice, such as – longer link lengths in campuses and industrial plants; resistance to electromagnetic and radio-frequency interference (EMI/RFI) may be necessary; and wider bandwidth capability, just to point-out a few examples,” Montgomery added.

The strong user demand for greater bandwidth and increased interconnectivity to the desktop, throughout the buildings, campuses, from LAN-to-LAN (Metropolitan Area Network - MAN) continues in 2014.

This is matched by rapidly growing demand for global broadband interconnectivity. Interactive multimedia terminals, triple play (voice, video and data), quadruple-play (adding mobility as a communications function to the network), and numerous other dynamics/ applications, continuing bring rapid access to massive databases, which increase productivity while providing rapid ROI (return on investment).

Such expanded capability, however, must often be obtained without making the current network elements obsolete. Local area network (LAN) applications illustrate this trend.  LANs are becoming larger and more complex. Reconfiguration, relocation, and extension of LANs are occurring more frequently, due to organization restructuring, advances in computer usage, and the trend toward decentralized computing.

These changes to LAN cabling represent a major ongoing operational expense and a disruption of work for many companies (enterprises). For example, adding capabilities often requires that network administrators upgrade their existing LANs to another media type: for example, copper-to-fiber, multimode-to-singlemode fiber, or even singlemode –to- different types of singlemode optical fiber (note: copper-to-copper conversion is not covered in the study). By using media converters, the network administrator can achieve these upgrades inexpensively.

According to ElectroniCast, the global use of fiber media converters in private datacom reached $1.07 billion in 2013 and is forecast to peak at $1.646 billion in 2017, before slipping to $1.628 billion in 2018.  

Private Datacom Fiber Media Converter Global Market Forecast,
(Value Basis, $ Million) – Source: ElectroniCast Consultants

Private Datacom Fiber Media Converter Global Market Forecast,

Note: Market forecast data in this study report refers to consumption (use) for a particular calendar year; therefore, this data is not cumulative data.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, 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.

Where can WDM-PON go next? -- DK Photonics

Where can WDM-PON go next?

The current generation of commercial WDM-PON/ 100GHz DWDM systems based on reflective ONU technology is optimized for applications up to 20 km, 40 channels, and 1 Gbps per customer. Current research focuses on how to scale WDM-PON toward higher bit rates and longer reach. Forward error correction is a key technology for scaling the current generation of WDM-PON technology to higher bit rates, longer reach, tighter channel spacing, or a combination thereof. An important challenge is to package the technology in an MSA form-factor pluggable module to maintain its benefits in cost and compatibility with third-party equipment.

A typical requirement for next generation metro/access systems is to enable node consolidation. That means operators can reduce opex by closing down portions of their central offices; at the same time, this goal requires the optical signals to bridge longer distances than what is typical of the access networks of today. Thus, when routing WDM-PON / 1064nm high power isolator signals through the metro part of the network, it becomes necessary to support ring architectures as an alternative to the basic tree structure.

In a ring structure, cascaded filters may decrease the effective channel passband. Since the spectral width of the WDM-PON signal is wider than the signals from a normal DFB source, such filtering effects may affect transmission.

In a recent evaluation project, a partnership between Transmode and Deutsche Telekom Hochschule für Telekommunikation of Leipzig, Germany, achieved 140-km long reach WDM-PON transmission over a ring-based access-network architecture. The partnership investigated the effects of using WDM-PON based on ASE-seeded wavelength-locked transmitters in a ring-based network architecture with cascaded CWDM OADM nodes. Transmission at 1.25 Gbps over 140-km singlemode fiber was demonstrated using an EDFA and dispersion compensation.

The results were first published at ECOC 2013 (In de Betou, Bunge, Åhlfeldt, and Olson, "140km Long-reach WDM-PON Test for Ring-based Access Network Architecture"). This partnership has investigated what opportunities could be provided by WDM-PON technology in such network topologies by studying experimentally the influence of narrow filtering and maximum reach.

The experimental testbed (in Leipzig) was built around Transmode's TM-Series iWDM-PON system to create an optical line terminal (OLT) (see Figure 2). The OLT has a transponder line card that hosts pluggable wavelength-locked Fabry-Perot transceivers, ASE seed light sources, dual circulators for up- and downstream, and a 40-channel multiplexer based on an AWG.

To reach distances beyond 100 km, amplifiers dispersion compensation, and remote ASE seed sources were used. While an experimental field trial today, it shows that WDM-PON may well continue to evolve to support longer reach and more sophisticated network architectures in the future supporting a broader range of deployment scenarios.

DK Photonics – www.dkphotonics.com specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as High Power Isolator,1064nm Components,PM Components,Pump Combiner,Pump Laser Protector,which using for fiber laser applications.Also have Mini-size CWDM, Optical Circulator, PM Circulator,PM Isolator, Fused Coupler,Mini Size Fused WDM.More information,please contact us.

WDM-PON technology-DK Photonics

WDM-PON provides the dedicated bandwidth of a point-to-point network and the fiber sharing inherent in PONs. The architecture is somewhat similar to that of EPON and GPON; instead of the power-splitter approach used in TDM-PON architectures, WDM-PON uses an arrayed waveguide grating (AWG) filter that separates the wavelengths for individual delivery to the subscriber ONUs (see Figure 1).

A simple, plug-and-play implementation is based on wavelength-locked or tunable lasers. Self-tuning "colorless" ONUs can be used at the subscriber sites to simplify inventory and spare-part handling. Colorless optics not only simplify operations, but also reduce deployment costs, since they don't need the expensive wavelength-stability components that traditional fixed and tunable optics require. There are multiple approaches to the colorless ONU technology.

In one approach, the wavelength of the ONU transmitter is controlled by injection of a "seed" signal into the transmitter (e.g., a wavelength-locked Fabry-Perot laser or reflective semiconductor optical amplifier). The seed signal injected into the transmitter could come from broadband ASE light sliced through the filters in the system or from a DFB laser array. In a self-seeding version of this approach, the seed light is provided by feedback of broadband light from the transmitter itself. The passive filtering of the seed light in the remote node determines the wavelength of the ONU transmitter.

In a different approach, the colorless ONU contains a singlemode optic coupler wavelength-tunable laser, which is able to tune to the appropriate wavelength that matches the remote node filter port.

Below 10-Gbps channel bit rates, the injection-seeded method provides a cost-efficient approach. As an example, a wavelength-locked Fabry-Perot transmitter can be integrated into an MSA SFP pluggable form-factor module, which enables the use of third-party CPE devices. A modified EDFA gain block in a 70×90 MSA form factor could be used to generate the broadband ASE light that's used as a seed signal in the system.

At 10-Gbps bit rates, tunable-laser technology offers an alternative to the injection-seeded approach. The tunable-laser technology developed for the metro/long-haul market has matured significantly over the past couple of years and is able to give a good cost-per-bit ratio when high capacity is needed.

If the WDM-PON system is properly designed, then it's possible to mix different transmission technologies. By following certain design rules during the installation of the WDM-PON system, it's possible to allow step-wise channel upgrades to higher bit rates when the demand arises. These design rules ensure that channel OSNR requirements will be met in the presence of reflections and that inter-channel crosstalk is avoided. The result is an open and flexible access network that can support many applications and services over the same infrastructure. WDM-PON thus becomes an optical option for the access network as and where it makes sense.

Given its ability to help service providers cope with current bandwidth demands as well as the next potential broadband access bottleneck, WDM-PON/ 100GHz DWDM Module is becoming an important technology to consider in terms of its benefits and market timing. As with any emerging technology, service providers need to consider the optimal strategy for initial deployment of WDM-PON. That includes how they could use WDM-PON for additional network applications as the technology matures and its costs come down.

WDM-PON technology

FIGURE 2. Architectural scenario explored in the collaboration between Transmode and Deutsche Telekom Hochschule für Telekommunikation.

The latest generations of WDM-PON systems are now gaining traction with operators around the globe for field deployment, lab trials, and evaluations. It's clearly the early stage of WDM-PON deployments, but progress has started and 2014 looks to be a pivotal year for the technology.

WDM-PON is a key component in next generation access(1)

Many industry analysts believe that the increasing requirements for bandwidth scalability, quality of service, and support of the emerging traffic patterns required by video and broadcast standards will make copper networks insufficient for many high-bandwidth services in the future. Fiber availability is not universal, and the economics of new fiber deployments are often challenging; nevertheless, fiber will undoubtedly push deeper into access networks to support business services, mobile backhaul/fronthaul, multitenant buildings/fiber to the cabinet, and in some cases fiber to the home (FTTH), too. Yet today‘s fiber-based approaches, including TDM-PON/PLC Splitter and active point-to-point Ethernet, probably won't meet the likely requirements of the next generation of bandwidth-intensive traffic, either.

WDM-PON is a passive optical networking approach -- currently being developed by several companies -- that can be used to more adequately address these challenges over fiber-based networks. A WDM-PON design can be used to separate optical-network units (ONUs) into several virtual point-to-point connections over the same physical infrastructure, a feature that enables efficient use of fiber compared to point-to-point Ethernet and offers lower latency than TDM-based approaches. A notable advantage of this approach is the combination of high capacity per user, high security, and longer optical reach. WDM-PON therefore is highly suitable for applications such as mobile backhaul or business Ethernet service provision.

Thus WDM-PON is poised to become the disruptive next generation access architecture. It will enable high-speed access for businesses, mobile backhaul, and eventually FTTH. WDM-PON also will enable operators to build converged networks and consolidate existing access networks, including potentially eliminating central offices to reduce cost while boosting performance.

There are several types of WDM-PON systems under development. They all have in common the use of passive, temperature-hardened DWDM optical filters in the remote node and colorless ONUs.

Basic WDM-PON architecture

FIGURE 1. Basic WDM-PON architecture.

DK Photonics – www.dkphotonics.com specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as High Power Isolator,1064nm Components,PM Components,Pump Combiner,Pump Laser Protector,which using for fiber laser applications.Also have Mini-size CWDM, Optical Circulator, PM Circulator,PM Isolator, Fused Coupler,Mini Size Fused WDM.More information,please contact us.

62.5/125 um Vs. 50/125um Multimode fiber Information

We have created this page to illustrate the very basic differences between 62.5 and 50/125 multimode fiber in selecting a patch cable for your existing cable plant.

62.5/125 um Vs. 50/125um Multimode fiber

62.5/125 um Vs. 50/125um Multimode fiber

The key thing to remember is to always use a patch cable of the same type as the cable that you are connecting to. It is virtually impossible to tell the difference between the two fiber types (62.5 and 50/125) by looking at the bare fiber* or the connectors*. Usually, this information will be written on the cable's jacket.

The photos above illustrate that the outer diameters of the two fiber types are the same. What is different is the size of the center light carrying core of the fiber. You cannot see the fiber's core without a microscope*. Therefore, you must rely on the writing that is on the fibers jacket to determine what type is.

Severe losses of light can occur when you try to match 50/125 and 62.5/125 fiber, as the illustration on the left shows.

* CAUTION: Never look directly into a fiber cable's end face or into the ferrule of a connector (with fiber present) as there may be dangerous laser light present.

NOTE: This page was designed to help you know the difference between 62.5 and 50/125 fiber for the purpose of purchasing patch cables and products to connect to existing installed cabling. This page was not designed to provide information on choosing between the two types fiber for new installations.

Comparation Between EPON and GPON(2)

Technical Maturity

Standard

EPON: IEEE802.3ah standard. The standard defines the physical layer of EPON MPCP, the OAM and other related contents. Basic principle for IEEE developing the EPON standard is 802.3 architecture EPON standardization work, minimal expansion of the standard Ethernet MAC protocol.

GPON: ITU-T G.984 series standard. The standard defines the provisions of the GPON physical layer, the TC layer and OAM functions. The GPON standard formulation to consider the support of traditional TDM services, still using the the 125s fixed frame structure to maintain 8K timing continuation. To support ATM multi-protocol, GPON defined an entirely new package structure GEM (GPON encapsulation method), ATM and other protocols can be mixed encapsulation framing.

Core chip

EPON: There are currently 5-6 professional firms providing the EPON core chip (excluding self-designed chip system vendors), these manufacturers have started to chip design and verification during the discussing of the standard, so most of them have launched a second-generation compatible and standard chip when the 802.3ah standard formally promulgated, which can quickly support the EPON system of large-scale deployment.

GPON: Except for the GPON chip, there is no the a professional chip manufacturers launched a commercial GPON core chip that independently designed by themselves. The GPON equipment modules are dedicated to the independent or collaborative development module, no the professional module manufacturers can provide samples, not to mention the mass production.

Multi-service Capabilities And Security

The most questions about EPON is its capacity of transmitting the traditional TDM EPON multi-service. Not to mention the current EPON equipment manufacturers to use the patented technology of the TDM over Ethernet provides TDM EPON single segment of the business of transmission channels, from the test results, and its performance is completely meet 1.5ms delay index requirements, in full compliance with the traditional TDM services standards. Even in ordinary Ethernet devices, now it also can use a variety of standard PWE3 (pseudowire emulation edge to edge) devices to provide cross-network segment, the end-to-end transparent traditional point-to-point TDM channel. With the dwindling proportion of traditional TDM traffic using packet switching technology TDM services asylum growing packet networks, will undoubtedly be a more economical means. Security, EPON standard AES-based encryption technology, with the security of GPON.

QoS

In QoS, EPON defines eight priority queues, DBA algorithms are also taken into account the priority queue bandwidth allocation strategy and fairness and other issues. IP a priority or Ethernet priority packet can be easily mapped to eight priority queues, and then through the DBA algorithm guarantees the transmission bandwidth and delay, QoS requirements fully meet the needs of different business . The GPON OLT detects the traffic load of each CONT-T for prediction / analysis ONU business flow and network congestion and allocate resources to each CONT-T, according to the network conditions, but does not involve the VP / VC, or Port_ID QoS. VP / VC, or Port_ID provide QoS guarantees by the corresponding mechanisms at both ends of the ATM / GEM client.

For different QoS requirements of the business, GPON by to use pointers arrangements ONU using the different transmission mode to achieve: to adjust its authorized bandwidth and authorization cycle to guarantee the bandwidth and latency requirements of the business. In fact, how to guarantee QoS EPON and GPON implementation mechanism is essentially the same. OAM including the GPON bandwidth authorized allocation, DBA, link monitoring, protection switching, key exchange, and various alarm functions. Itself from the standard point of view, the GPON standard defined richer OAM information than the the EPON standard definition, but from the actual equipment of view, both provide the functionality and not much difference, the current EPON equipment can also provide these features. 

To sum up, in terms of QoS, multi-service bearer security, the current EPON products are similar with GPON standard specified. But the cost per unit bandwidth is much lower than the EPON, besidesl EPON technology is more mature, earlierbe accepted by the market, and earlier enter the commercial stage  in large-scale. The next generation network is a packet-based network, Ethernet as the absolute mainstream bearing platform of the packet network has become an indisputable fact. The user network interface in the future is certainly an Ethernet interface, the Ethernet interface on the MAN will surely be ubiquitous. Using Ethernet technology to connect the Ethernet interface on both sides will be a very natural thing.

What is Pump Laser Protector, Where is the Pump Laser Protector use?

The Pump Laser Protector (also called Pump Protection Filters) is a passive component which allows maximum transmission from a discrete fibre-coupled pump laser diode and blocks parasitic signals around the centre wavelength of the laser from being reflected back into the laser.

Multimode Pump Laser Protector -10~30W

Single-emitter laser diodes are highly regarded for their long term reliability. However, these devices are very sensitive to backward propagating light within the delivery fiber. Backward power imaged onto the diode material, as small as 5% of the pump diode output, can cause accelerated diode degradation and, in the majority of cases, catastrophic failure.That is why we need Pump Laser Protector.

DK Photonics offers filter technology that provides protection to pump diodes under these conditions (up to 50 dB Backward Signal Attenuation). Splicing these filters to the pump output fiber rejects unwanted light before it reaches the diode.

Multimode Pump Protection filters are available for a wide range of standard light emitting diodes. Fiber pigtails are 105/125 micron, with both 0.15 and 0.22 NA cores and 50/125 or 62.5/126 MM fiber available. Operating wavelengths cover the majority of diode laser lines (915 nm, 940 nm, 960 nm and 976) and maximum power handling is 25W without water-cooling.DK Photonics recently released a new type of Pump Laser Protector up to 200W handling power with water-cooling technology. And also have SingleMode Pump Laser Protector with Hi1060 fiber for 976nm fiber laser.

If you do not see a Pump Laser Protector from the standard configurations that meets your needs, we welcome the opportunity to review your desired specification and quote a filter best suited to your application. Different pump/rejection wavelengths or fiber pigtail can be accommodated.

DK Photonics – www.dkphotonics.com specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such asDK Photonics' promotion products including:High Power Isolator,1064nm Components,PM Components,Pump Combiner,Pump Laser Protector,which using for fiber laser applications.Also have Mini-size CWDM, Optical Circulator, PM Circulator,PM Isolator, Fused Coupler,Mini Size Fused WDM.More information,please contact us.

What is Cladding Power Strippers, Where is the Cladding Power Strippers use?

Cladding Power Strippers: devices which can remove light from a fiber cladding.

Cladding Power Stripper

Where is the Cladding Power Strippers use?

In some situations, it is necessary to remove light from the cladding of an optical fiber. Some examples:

-Sometimes, a single-mode fiber is used as a kind of mode cleaner. The wanted light is transmitted through the fiber core, and any other light, spoiling the beam quality, should be removed. In many cases, a polymer coating around the fiber cladding can serve as a Cladding Power Stripper. For that purpose, the refractive index of the coating should be slightly above that of the cladding, so that light can easily be transmitted from the cladding into the coating and then radiated into the ambient air by scattering at irregularities. (Alternatively, the coating may absorb the light.)

-In a high-power fiber amplifier made from a double-clad fiber, residual (unabsorbed) pump light (at the fiber end opposite to the pump end) may have to be removed from the pump cladding (inner cladding) in order to prevent it either from accompanying the amplified signal or from getting to the signal source. A special Cladding Power Stripper may be used for that purpose.

-When pump light is launched into a double-clad fiber (for example, from free space), some of the optical power may get into the outer cladding around the pump cladding. It may propagate in that outer cladding up to a location where the fiber has a polymer coating, and then destroy that coating via excessive heating. That problem may be avoided with a cladding stripper which attenuates light in the outer cladding, but not in the pump cladding.

Cladding Power Stripper for use in high-power fiber lasers and amplifiers need to be able to handle substantial optical powers. It needs to be ensured that these powers are absorbed in a sufficiently widespread region, and that the generated heat can be removed safely, without damaging the mode stripper or any surrounding parts.

DWDM & CWDM Solutions

In today’s world of intensive communication needs and requirements, “fiber optic cabling” has become a very popular phrase.  In the field of telecommunications, data center connectivity and ,video transport, fiber optic cabling is highly desirable for today’s communication needs due to the enormous bandwidth availability, as well as reliability, minimal loss of data packets, low latency and increased security.  Since the physical fiber optic cabling is expensive to implement for each individual service, using a Wavelength Division Multiplexing (WDM) for expanding the capacity of the fiber to carry multiple client interfaces is a highly advisable.  WDM is a technology that combines several streams of data/storage/video or voice protocols on the same physical fiber-optic cable by using several wavelengths (frequencies) of light with each frequency carrying a different type of data. With the use of optical amplifiers and the development of the  OTN  (Optical Transport Network) layer equipped with FEC (Forward Error Corection), the distance of the fiber optical communication can reach thousands of Kilometers without the need for regeneration sites.

DWDM vs. CWDM

DWDM (Dense Wavelength Division Multiplexing) is a technology allowing high throughput capacity over longer distances commonly ranging between 44-88 channels/wavelengths and transferring data rates from 100Mbps up to 100Gbps per wavelength. Each wavelength can transparently carry wide range of services such as FE/1/10/40/100GBE, OTU2/OTU3/OTU4, 1/2/4/8/10/16GB FC,STM1/4/16/64, OC3/OC12/OC48/OC-192, HD/SD-SDI and CPRI.  The channel spacing of the DWDM solution is defined by the ITU.xxx (ask Omri) standard and can range from 25Ghz, 50GHz and 100GHz which is the most widely used today. Figure – 1 shows a DWDM spectral view of 88ch with 50GHz spacing.

Figure -1: Spectral view of 50GHz spacing 88 DWDM channels/wavelengths

DWDM systems can provide up to 96 wavelengths (at 50GHz) of mixed service types, and can transport to distances up to 3000km by deploying amplifiers, as demonstrated in figure 2) and dispersion compensators thus increasing the fiber capacity by a factor of x100.  Due to its more precise and stabilized lasers, the DWDM technology tends to be more expensive at the sub-10G rates, but is a more appropriate solution and is dominating for 10G service rates and above providing large capacity data transport and connectivity over long distances at affordable costs. The DWDM solution today is often embedded with ROADM (Reconfigurable Optical Add Drop Multiplexer) which enables the building of flexible remotely managed infrastructure in which any wavelength can be added or dropped at any site. An example of DWDM equipment is well demonstrated by PL-1000, PL-1000GM, PL-1000GT, PL-1000RO, PL-2000 and PL-1000TN by DK Photonics Networks.

Figure-2 Optical amplifier used in DWDM solution to overcome fiber attenuation and increase distance

CWDM (Coarse Wavelength Division Multiplexing) proves to be the initial entry point for many organizations due to its lower cost.  Each CWDM wavelength typically supports up to 2.5Gbps and can be expanded to 10Gbps support.  This transfer rate is sufficient to support GbE, Fast Ethernet or 1/2/4/8/10G FC, STM-1/STM-4/STM-16 / OC3/OC12/OC48, as well as other protocols.  The CWDM is limited to 16 wavelengths and is typically deployed at networks up to 80Km since optical amplifiers cannot be used due to the large spacing between channels. An example of this equipment is well demonstrated by PL-400, PL-1000E and PL-2000 by DK Photonics Networks.

It is important to note that the entire suite of DK Photonics’ equipment is designed to support both DWDM and CWDM technology by using standards based pluggable optical modules such as SFP, XFP and SFP+. The technology used is carefully calculated per project and according to customer requirements of distance, capacity, attenuation and future needs. DK Photonics also provides migration path from CWDM to DWDM enabling low entry cost and future expansion that can be viewed in the DWDM over CWDM technology page

WDM Installation

For designing and implementing a WDM network, there is a need to know some basic information regarding the infrastructure such as fiber type, attenuation of fiber, distance of fiber, network topology, service type, rate and connectivity. Based on this information, calculation of the optical link budget, OSNR (Optical Signal Noise Ratio) and dispersion can be performed in order to provide reliable, error free layer-1 optical solution.

DK Photonics’ WDM diversified equipment portfolio can provide either CWDM or DWDM solution for 4 wavelengths or 88 wavelengths ranging from few km to thousands of km and fit to the exact customer network needs. The network can be a point-to-point, linear add/Drop or ring Topology with passive Mux/DeMux or ROADM based infrastructure.

The WDM equipment serves as a demarcation point and is installed behind the Ethernet switch, router fiber channel SAN Fabric or SDH/SONET ADM coloring the fiber into different spectral wavelengths and multiplexing the rates fully isolated from each other over the same fiber to the remote site.  This allows transmission of multiple channels of different services and rates of data over the same fiber utilizing the fiber resources agnostically to the service type and rate.

The WDM technology can be applied to multiple applications such as connecting building service agnostic optical layer backbone,  data centers connectivity, Video broadcast, LTE fiber, cloud computing backbone, increasing existing fiber bandwidth and spectral efficiency.

Figure 3 shows the main traditional and emerging CWDM and DWDM technology applications which keep  growing along with the rise of the cloud computing and CSP (Content Service Providers) as well as Smart phones and video applications causing constant increase  to the WDM technology deployment and new capacities such as 100G.

Figure 3 – Main CWDM and DWDM technology applications

DK Photonics’ WDM products designed for easy and fast implementation take up minimal space and use least power, thus providing the highest integration level of CWDM and DWDM networks in the smallest 1U footprint, while providing high ROI. Additionally, the CWDM DWDM optical network is managed remotely with either DK Photonics’ Light Watch NMS/EMS or the imbedded web based management system as well as via any 3rd party SNMP tool.

Read more related articles :

Filter-based WDM          CWDM            Mini CWDM Module       DWDM