Category: Fiber Transceivers

Optical transceivers, Active Optic Cables, data center switches, and cable management in data centers.

Do You Know About Fiber Optic Splitter?

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today’s optical network topologies, the advent of fiber optic splitter is significant in helping users maximum the performance of optical network circuits. Fiber optic splitter, or sometimes called as beam splitter, is a passive optical component that can split an incident light beam into two or more light beams, and vice versa. The device contains multiple input and output ends. Whenever the light transmission in a network needs to be divided, fiber optic splitter can be implemented for the convenience of network interconnections.
How Does Fiber Optic Splitter Work?
As for the working principle of fiber optic splitter, it can be generally described in the following way. When the light signal transmits in a single-mode fiber, the light energy can not entirely concentrated in the fiber core. A small amount of energy will be spread through the cladding of fiber. That is to say, if two fibers are close enough to each other, the transmitting light in an optical fiber can enter into another optical fiber. Therefore, the reallocation technique of optical signal can be achieved in multiple fibers. And this is how fiber optic splitter comes into being.
Classification of Fiber Optic Splitter
At present, there are two types of fiber optic splitters. One is known as PLC (planar lightwave circuit) splitter, and another one is known as FBT (fused biconical taper) splitter.
1) PLC splitter divides the incoming signal into multiple outputs by using an optic splitter chip. One optic splitter chip is able to achieve at most 64 ends. PLC splitter is usually used for larger applications. The losses of PLC splitter are not sensitive to the wavelength, which satisfies the need for multiple wavelengths transmission. PLC splitter’s configuration is compact and its size is small, thus the installation space can be greatly saved.
2) FBT splitter is fused with a heat source similar to a one-to-one fusion splice. Fibers are stretched under a heating zone to form a double cone. The cost of FBT splitter is lower due to the commonly used materials, and the splitting ratio is adjustable. But the losses are sensitive to wavelengths. Device should be chosen according to wavelengths. And it is unable to offer the uniform spectroscopy.
Applications
1) Passive monitoring application of fiber optic splitter is used for the maintenance of long-haul network, cable TV ATM circuit or local area/metro area network. The splitter taps into a small percentage of optical traffic. Majority of the signal arrives its destination, but a small percentage is directed to a local access port. The application can be done by manual operation for troubleshooting purposes or by connecting the splitter to a network monitoring system for ongoing maintenance and performance assessment.
2) Fiber optic splitter can also be used for FTTx/PON application. This enables to reduce the physical fiber usage or the basic quantity of required fibers. A single fiber can be split into many branches to support multiple end users. The strain on the fiber backbone can be greatly decreased through the application.
Conclusion
To sum up, fiber optic splitter provides a solution for improving the efficiency of optical infrastructures. PLC splitter and FBT splitter are varied in different aspects, hence choosing the right type of splitter for your network is also important. fiber-mart.com.COM provides all the above fiber optic splitters. Please visit fiber-mart.com for more information.

What Is a Fiber Optic Splitter?

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The fiber optic splitter is also referred to as optical splitter, which is an integrated waveguide optical power distribution device. It plays an important role in passive optical network (EPON, GPON, BPON, FTTX, FTTH and so on) by allowing a single PON interface to be shared among many subscribers. To achieve this, it is designed to split an incident light beam into two or more light beams and couple the light beams to the branch distribution as an optical fiber tandem device, which has the function to maximize the performance of network circuits.
How Optical Splitter Works?
In general, a optical splitter has many input and output terminals to attain the branch of the light beams and maximize the functionality of optical network circuits. The passive optical splitter can split, or separate, an incident light beam into several light beams at a certain ratio. As a simple example, Figure 1 shows how optical splitter with 1×4 split configurations can separate an incident light beam from a single input fiber cable into four light beams and transmit them through four individual output fiber cables. For instance, if the input fiber optic cable carries 1000 Mbps bandwidth, each user in the end of output fiber cables can use the network with 250 Mbps bandwidth.
As for the optical splitter with 2×64 split configurations, it is more complicated than the optical splitter with 1×4 split configurations. There are two input terminals and sixty-four output terminals in the optical splitter with 2×64 split configurations. Its function is to split two incident light beams from two individual input fiber cables into sixty-four light beams and transmit them through sixty-four light individual output fiber cables.
What should be noted is that the ejected light beams may or may not have the same optical power as the incident light beam. The designer would better to take it into consideration when designing the passive optical networks.
Optical Splitter Types Classified by Package Style
The optical splitter can be terminated with different forms of connectors, and the primary package could be box type or stainless tube type. Fiber optic splitter box is usually used with 2mm or 3mm outer diameter cable, while the other is normally used in combination with 0.9mm outer diameter cables. Besides, it has variously different split configurations, such as 1×2, 1×8, 2×32, etc. With the development of the optical splitter manufacturing technology, the fiber optic market can support the high-technical splitter used in the network where the split configurations are 2×64 or larger at present.
Optical Splitter Types Classified by Transmission Medium
According to the different transmission medium, there are single mode optical splitter and multimode optical splitter. For multimode ones, the phrase implies that the fiber is optimized for 850nm and 1310nm operation. For single mode ones, the phrase means that the fiber is optimized for 1310nm and 1550nm operation. Meanwhile, based on working wavelength difference, there are single window and dual window optical splitters. The single window fiber optic splitter is to use one working wavelength, while the dual window fiber optic splitter is with two working wavelengths.
Optical Splitters Types Classified by Manufacturing Technique
On the basis of different manufacturing technique, there are two fiber optic splitter types, which are popularly used nowadays. One is the traditional fused type optical splitter, fused biconic tapered (FBT) splitter, which features competitive prices; and the other is planar lightwave circuit (PLC) splitter, which has compact size and suits for high-density applications. Both of them have the advantages and can be used in different applications.
Fused Biconic Tapered (FBT) Optical Splitters
The FBT splitter (See Figure 2) is fabricated by the traditional technology with over 20 years history. Its manufacturing technique is relatively mature and the manufacturing cost is lower than PLC splitter, so that the FBT optical splitter can be deployed in a cost-effective manner in today’s fiber optic market.
In the manufacturing process of FBT splitter, there are two or more fibers placed closely together, typically twisted around each other and fused together by applying heat while the assembly is being elongated and tapered. The fused fibers are protected by a glass substrate and then protected by a stainless steel tube. Meanwhile, there is a signal source controls the desired coupling ratio to meet the requirements in applications.
Nowadays, FBT splitters are widely used in passive optical networks, especially in the network where the split configuration is not larger than 1×4. In fact, there is a slight drawback of FBT splitter, the split configuration. In details, if more than four splits are required, multiple FBT splitters can be spliced together in concatenation to multiply the amount of splits available, like a tree splitter. By using this design, the package size increases due to multiple FBT splitters and the insertion loss also increases with the additional splitters. Therefore, if high split counts are needed, small package size and low insertion loss are also required, you are suggested to choose a PLC splitter, instead of the FBT splitter.
Planar Lightwave Circuit (PLC) Optical Splitters
With a more recent technology, the PLC splitter (See Figure 3) provides a better solution for applications with larger split configurations. Clearly different from the manufacturing technique of FBT splitters, in the manufacturing process of PLC optical splitters, the waveguides are fabricated by using lithography onto a silica glass substrate, which allows for routing specific percentages of light. As a result, the PLC splitter offers very accurate splits with minimal loss in an efficient package.
PLC splitters
With the rapid growth of FTTx worldwide, the requirement for larger split configurations (1×32, 2×64, etc.) in these networks has also grown in order to serve mass subscribers. Due to its performance benefit of larger split configurations, the PLC splitter is more commonly used in the network where the split configuration is larger than 1×4.

What’s The Difference Between EPON And GPON Optical Fiber Networks?

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EPON and GPON are popular versions of passive optical networks (PONs). These short-haul networks of fiber-optical cable are used for Internet access, voice over Internet protocol (VoIP), and digital TV delivery in metropolitan areas. Other uses include backhaul connections for cellular basestations, Wi-Fi hotspots, and even distributed antenna systems (DAS). The primary differences between them lie in the protocols used for downstream and upstream communications.
A PON is a fiber network that only uses fiber and passive components like splitters and combiners rather than active components like amplifiers, repeaters, or shaping circuits. Such networks cost significantly less than those using active components. The main disadvantage is a shorter range of coverage limited by signal strength. While an active optical network (AON) can cover a range to about 100 km (62 miles), a PON is typically limited to fiber cable runs of up to 20 km (12 miles). PONs also are called fiber to the home (FTTH) networks.
The term FTTx is used to state how far a fiber run is. In FTTH, x is for home. You may also see it called FTTP or fiber to the premises. Another variation is FTTB for fiber to the building. These three versions define systems where the fiber runs all the way from the service provider to the customer. In other forms, the fiber is not run all the way to the customer. Instead, it is run to an interim node in the neighborhood. This is called FTTN for fiber to the node. Another variation is FTTC, or fiber to the curb. Here too the fiber does not run all the way to the home. FTTC and FTTN networks may use a customer’s unshielded twisted-pair (UTP) copper telephone line to extend the services at lower cost. For example, a fast ADSL line carries the fiber data to the customer’s devices.
The typical PON arrangement is a point to multi-point (P2MP) network where a central optical line terminal (OLT) at the service provider’s facility distributes TV or Internet service to as many as 16 to 128 customers per fiber line (see the figure). Optical splitters, passive optical devices that divide a single optical signal into multiple equal but lower-power signals, distribute the signals to users. An optical network unit (ONU) terminates the PON at the customer’s home. The ONU usually communicates with an optical network terminal (ONT), which may be a separate box that connects the PON to TV sets, telephones, computers, or a wireless router. The ONU/ONT may be one device.
In the basic method of operation for downstream distribution on one wavelength of light from OLT to ONU/ONT, all customers receive the same data. The ONU recognizes data targeted at each user. For the upstream from ONU to OLT, a time division multiplex (TDM) technique is used where each user is assigned a timeslot on a different wavelength of light. With this arrangement, the splitters act as power combiners. The upstream transmissions, called burst-mode operations, occur at random as a user needs to send data. The system assigns a slot as needed. Because the TDM method involves multiple users on a single transmission, the upstream data rate is always slower than the downstream rate.
GPON
Over the years, various PON standards have been developed. In the late 1990s, the International Telecommunications Union (ITU) created the APON standard, which used the Asynchronous Transfer Mode (ATM) for long-haul packet transmission. Since ATM is no longer used, a newer version was created called the broadband PON, or BPON. Designated as ITU-T G.983, this standard provided for 622 Mbits/s downstream and 155 Mbits/s upstream.
While BPON may still be used in some systems, most current networks use GPON, or Gigabit PON. The ITU-T standard is G.984. It delivers 2.488 Gbits/s downstream and 1.244 Gbits/s upstream.
GPON uses optical wavelength division multiplexing (WDM) so a single fiber can be used for both downstream and upstream data. A laser on a wavelength (λ) of 1490 nm transmits downstream data. Upstream data transmits on a wavelength of 1310 nm. If TV is being distributed, a wavelength of 1550 nm is used.
While each ONU gets the full downstream rate of 2.488 Gbits/s, GPON uses a time division multiple access (TDMA) format to allocate a specific timeslot to each user. This divides the bandwidth so each user gets a fraction such as 100 Mbits/s depending upon how the service provider allocates it.
The upstream rate is less than the maximum because it is shared with other ONUs in a TDMA scheme. The OLT determines the distance and time delay of each subscriber. Then software provides a way to allot timeslots to upstream data for each user.
The typical split of a single fiber is 1:32 or 1:64. That means each fiber can serve up to 32 or 64 subscribers. Split ratios up to 1:128 are possible in some systems.
As for data format, the GPON packets can handle ATM packets directly. Recall that ATM packages everything in 53-byte packets with 48 for data and 5 for overhead. GPON also uses a generic encapsulation method to carry other protocols. It can encapsulate Ethernet, IP, TCP, UDP, T1/E1, video, VoIP, or other protocols as called for by the data transmission. Minimum packet size is 53 bytes, and the maximum is 1518. AES encryption is used downstream only.
The latest version of GPON is a 10-Gigabit version called XGPON, or 10G-PON. As the demand for video and over the top (OTT) TV services has increased, there is an increasing need to boost line rates to handle the massive data of high-definition video. XGPON serves this purpose. The ITU standard is G.987.
XGPON’s maximum rate is 10 Gbits/s (9.95328) downstream and 2.5 Gbits/s (2.48832) upstream. Different WDM wavelengths are used, 1577 nm downstream and 1270 nm upstream. This allows 10-Gbit/s service to coexist on the same fiber with standard GPON. Optical split is 1:128, and data formatting is the same as GPON. Maximum range is still 20 km. XGPON is not yet widely implemented but provides an excellent upgrade path for service providers and customers.
Most PONs are configured like this. The number of splitters and split levels varies with the vendor and the system. Split ratios are usually 1:32 or 1:64 but could be higher.

Understanding the FTTx Network

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FTTx technology plays an important role in providing higher bandwidth for a global network. And FTTx (fiber to the x) architecture is a typical example of substituting copper by fiber in high data rate traffic. According to the different termination places, the common FTTx architectures include FTTH, FTTB, FTTP, FTTC, and FTTN. This article will introduce these architectures respectively.
What is FTTx Network?
FTTx also called as fiber to the x, is a collective term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile telecommunications.
Different FTTx Architectures
FTTP: fiber-to-the-premises, is a loosely used term, which can encompass both FTTH and FTTB or sometimes is used a particular fiber network that includes both homes and businesses. It depends on how the context is used and a specific location of where the fiber terminates. FTTP can offer higher bandwidth than any other broadband services, so operators usually use this technology to provide triple-play services.
FTTH: as indicated by the name fiber-to-the-home, fiber from the central office reaches the boundary of the living space, such as a box on the outside wall of a home. Once at the subscriber’s living or working space, the signal may be conveyed throughout the space using any means, such as twisted pair, coaxial pair, wireless, power line communication, or optical fiber. Passive optical networks (PONs) and point-to-point Ethernet are architectures that deliver triple-play services over FTTH networks directly from an operator’s central office.
FTTB (fiber to the building) — Fiber terminates at the boundary of the building. A fiber cable in FTTB installation goes to a point on shared property and the other cabling provides the connection to single homes, offices or other spaces. FTTB applications often use active or passive optical networks to distribute signals over a shared fiber optic cable to individual households of offices.
FTTC( fiber-to-the-curb or -cabinet), is a telecommunication system where fiber optic cables run directly to a platform near homes or any business environment and serve several customers. Each of these customers has a connection to this platform via coaxial cable or twisted pair. The term “curb” is an abstraction and just as easily means a pole-mounted device or communications closet or shed. Typically any system terminating fiber within 1000 ft (300 m) of the customer premises equipment would be described as FTTC. A perfect deployment example of FTTC is a DLC/NGDLC (digital loop carrier) which provides phone service.
FTTN (fiber to the node) — Fiber terminates in a street cabinet, which may be miles away from the customer premises, with the final connections being copper. One of the main benefits of FTTN is the ability to deliver data over more efficient fiber optic lines, rather than other fiber optic lines with the greater speed restriction
Conclusion
The advent of the FTTx network is of great significance for people around the world. As it has a higher speed, costs less, and carries more capacity than twisted pair conductor or coaxial cables.

WHAT IS FTTX OR FIBER TO THE X?

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“Fiber to the X” sounds like something really big, like to the “Nth degree.” It is one of the reasons that around 20,000 professionals plan to meet up at CommunicAsia June 26 – 28, 2018 in Singapore to gather info and develop business around it. FTTX is a situation in which all available optical fiber topologies from a telecommunications or cable carrier point to its customers. This is based on (not outside) the location of the fiber termination point. FTTC and FTTN (curb and neighborhood) are similar because the fiber ends outside the building.
Whereas, FTTC and FTTN (curb and neighborhood) are a little different. The fiber, in these cases, ends outside a building, not inside the building. FTTH and FTTP (home and premises) mean the same. FTTE (enclosure) refers to a junction box on a floor or in a department in a bigger facility.
FTTX, FTTH and FTTP are a must-have because of individuals’ and organizations’ increasing appetite for network, network and more network. The number of voice, image and video files shared on networks is bigger than ever and will continue to increase.
FTTx offers a huge amount of bandwidth to meet today’s needs better than ever. It lines up well with the triple play of voice, video and data and now people expect a converged multi-play services environment with huge bandwidth requirements. Apps and services like Hulu, Pluto, Amazon Alexa, WhatsApp, GoDaddy (web hosting, ISP, and DID number provider) and Zoom.us as well as, in general VOIP, RF video, online gaming that enables video and voice while playing, cyber security, and smart everything are depend upon FTTx networks.

What You Need to Know When Using 10G over CWDM

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Both Passive CWDM and DWDM have been viable solutions in the telecommunications industry, but now, 10G Ethernet is appearing to be the most preferred solution over CWDM, everyone is migrating to the use of 10G Ethernet. This encourages many engineers to figure out how they ought to adjust their new designs to support the transition from 10G to CWDM. If you’re one of these designers who’s attempting to navigate the transition, the following is what you need to know.
Bandwidth Exts are Easier
In past years, designers who want to increase or improve their bandwidth could achieve this easily over a single or duplex mode fiber. During this period, the 1G Ethernet and CWDM solutions were sufficient, and the only limiting element was the power budget of the optical transceiver or the attenuation of your fiber. That it was possible to transmit up to 200 kilometers and utilize just a 1G Ethernet when designers preferred cheap CWDM.
Now, many people are considering the 10G Ethernet solutions, and that’s why it’s necessary to understand how everything will differ when using 10G over CWDM. When intending to migrate to 10G, you need to know the fiber type. For the dispersion and attenuation calculation, every designer need to know the recommended parameters from ITU-T and understanding the vendor and product kind of the fiber could also help. Remember that the physical fiber will work better than the standards claim most of the time.
Chromatic dispersion is referred to as the time variance of a single pulse of a signal. To summarize, chromatic dispersion is “the spreading of a light pulse per unit source spectrum width in an optical fibre due to the various group velocities of the different wavelengths composing the source spectrum” or in layman’s terms, “the signal is stretched on the fiber transmission path due the dispersion characteristics of the transporting fiber.”
Chromatic dispersion always exists, but the higher the link speed is, the greater important it becomes. For instance, a wavelength of 1310nm have a 0 ps/nm chromatic dispersion and 5, 25 dB fiber attenuation. In comparison, a wavelength of 1610 nm have a 330 ps/nm chromatic dispersion and a 3,45 dB fiber attenuation.
CWDM Over DWDM 10G is Cost-Effective
Designers should bear it in mind that CWDM implementation is more cost effective than passive DWDM infrastructure. These solutions will be more expensive because DWDM lasers cost more. DWDM lasers are essentially DFB lasers which are cooled, however, they are recommended as they contain the longevity that are required in these solutions. If you would like transmit a signal over a large distance, you should think about large metro ring topologies.
Though 10GBASE DWDM is more expensive, it’s become the first choice because users have started to consider the costs after dividing it over the quantity of customers served. Some customers are more cost-conscious and have lower bandwidth capacity requirements; so, the cheap CWDM infrastructure will make more sense.
Remember that the new 10GBASE DWDM services is usually added over the same fiber. This will enhance the support of the initial CWDM infrastructure capacity by 4 times. This is irresistible to many designers.