Category: Fiber Transceivers

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

Introduction to Semiconductor Optical Amplifier (SOA)

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Optical amplifier, with the introduction in 1990s, conquered the regenerator technology and opened doors to the WDM technology. It is mainly used to amplify an optical signal directly, without the need to first convert it to an electrical signal. There are many types of optical amplifiers, namely Raman amplifiers, erbium doped-fiber amplifiers (EDFAs), and semiconductor optical amplifier (SOA). This article will make a clearer introduction to SOA amplifier, and analyze its advantages and disadvantages.
The Basics of Semiconductor Optical Amplifier (SOA)
SOA optical amplifiers use the semiconductor as the gain medium, which are designed to be used in general applications to increase optical launch power to compensate for loss of other optical devices. Semiconductor optical amplifiers are often adopted in telecommunication systems in the form of fiber-pigtailed components, operating at signal wavelengths between 0.85 µm and 1.6 µm and generating gains of up to 30 dB. Semiconductor optical amplifier, available in 1310nm, 1400nm, 1500nm, 1600nm wavelength, can be used with singlemode or polarization maintaining fiber input/output.
Key Points of SOA Amplifier
1310 nm, 1400 nm, 1550 nm and 1610 nm wavelength selectable
High fiber-to-fiber gain of 20 dB
Up to 16 dBm output
1 MHz with 10 ns pulse width (optional)
PM Panda fiber input/output (optional)
Similar to lasers, but with non-reflecting ends and broad wavelength emission
Incoming optical signal stimulates emission of light at its own wavelength
Process continues through cavity to amplify signal
Working principle of SOA amplifier
The basic working principle of a SOA is the same as a semiconductor laser but without feedback. SOAs amplify incident light through simulated emission. When the light traveling through the active region, it causes these electrons to lose energy in the form of photons and get back to the ground state. Those stimulated photons have the same wavelength as the optical signal, thus amplifying the optical signal.
SOA Over EFDA in DWDM Networks
As the solution below, 120km Metro Networks by Using an SOA amplifier. You may wonder why not use EDFA in the above networks.
Theoretically, SOA optical amplifiers are not comparable with EDFA in the terms of performance. The noise figure of SOA optical amplifier is typically higher, the gain bandwidth can be similar, SOAs exhibit much stronger nonlinear distortions in the form of self-phase modulation and four-wave mixing. Yet, the semiconductor optical amplifier is of small size and electrical pumped, which is often less expensive than EDFA. Additionally, SOA can be run with a low power laser.
How to Choose SOA Optical Amplifier?
When selecting SOA amplifier, you have to check the every detailed parameter in the product data sheet. But, seriously, do you understand it? No, please read the following part.
The key parameters used to characterize a SOA amplifier are gain, gain bandwidth, saturation output power and noise.
Gain is the factor by which the input signal is amplified and is measured as the ratio of output power to input power (in dB). A higher gain results in higher output optical signal.
Gain bandwidth defines the range of bandwidth where the amplification functions. A wide gain bandwidth is desirable to amplify a wide range of signal wavelengths.
Saturation output power is the maximum output power attainable after amplification beyond which no amplification is reached. It is important that the SOA has a high power saturation level to remain in the linear working region and to have higher dynamic range.
Noise defines the undesired signal within the signal bandwidth which arises due to physical processing in the amplifier. A parameter called noise figure is used to measure the impact of noise which is typically around 5dB.

 

Why Third-party 40G QSFP+ Transceiver, Instead of OEM QSFP Module?

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For the data center or network upgrade, 40G network is a trending choice. Then where do you buy the 40G QSFP transceiver? Will you choose an OEM one or a third-party one? There are some differences between third-party 40G QSFP transceiver and OEM 40G QSFP transceiver, which will be shown below.
Features of OEM 40G QSFP Transceiver Modules
As we know, the OEM 40G QSFP transceiver from name brand like Cisco, Juniper and Brocade is widely used in data center and enterprise network. They all have some great features. The Cisco 40G QSFP transceiver offers a wide variety of high-density and low-power 40 Gigabit Ethernet connectivity options for data center, high-performance computing networks, enterprise core and distribution layers, and service provider applications. Here are some benefits of Cisco 40 Gbps transceiver:
Hot-swappable input/output device that plugs into a 40 Gigabit Ethernet Cisco QSFP port
Flexibility of interface choice (for different reach requirements and fiber types)
Interoperable with other IEEE-compliant 40GBASE interfaces where applicable
Certified and tested on Cisco QSFP 40G ports for superior performance, quality, and reliability
High-speed electrical interface compliant to IEEE 802.3ba
QSFP Form factor, 2-wire I2C communication interface and other low-speed electrical interface compliant to SFF 8436 and QSFP。
The Brocade 40 Gbps transceiver supports highly reliable operations in data center and is optimized for Brocade switching platforms. It undergoes strict qualification and certification testing.
Why Choose 3rd 40G QSFP Optical Transceivers Over OEM?
40G QSFP transceiver from Cisco and Brocade is reliable and with high-quality, but why so many third-party 40 Gbps transceiver occurred on the market? The answer seems simple, the transceiver market need it. With high-speed development of the optical communication industry, the demand for 40G QSFP transceiver is increasing. The third-party 40G QSFP with good compatibility and high stability is the perfect choice for some customers. Here are some amazing advantages of the third-party 40 Gbps transceiver:
Price advantage
Optics that you buy directly from name brand is expensive because it includes the costs of testing and validation, and the majority of what you pay for goes into their pocket as pure profit. While the third-party providers may not use the same testing procedures as the name brand, but most have nearly 100% success in compatibility. The third-party providers don’t mark up the 40G QSFP as much as the name brand, so they offer better price for the customer.
Quality and Reliability
The third-party 40Gbps transceiver is reliable as the original one if you buy from a reliable optics provider. Usually, the reliable third-party provider will offer warranty and support after you buy from them, because they are highly focused and specialize in the optical transceiver market.
More choice for 40G QSFP transceiver
The third-party optical transceiver is compatible for most name brand transceivers, so it will have more choice for your data center and enterprise networks.
For the 40 Gbps transceiver, fiber-mart.COM provides various of compatible brands for you, Cisco, Genetic, Juniper Networks, Arista Networks, Brocode, HPE, Dell, Intel, IBM, etc. All have passed the compatibility testing.

Decoding Grade A Connector in Fiber Optic Cables

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With the advances in fiber optic technology and transmission systems, reliable cabling systems are becoming even more important. Active optical equipment, which is often worth hundreds of thousands of dollars, is all connected into the network via the humble fiber optic patch cord or patch lead. The risk of network downtime due to unreliable cabling is one that should be avoided. Therefore, these types of networks, along with many other Data Center and high speed Commercial networks require reliable cabling infrastructure in order to maximize performance and to ensure long term reliability. Today’s article will introduce Grade A optical fiber cables.
What Are Grade A, Grade B, Grade C Fiber Optic Connector?
IEC standards dictate the connector performance requirement for each grade of fiber optic patch cord connector. These standards guide end users and manufacturers in ensuring compliance to best practices in optical fiber technology.
According to IEC 61753 and IEC 61300-3-34 Attenuation Random Testing Method, Grade C connectors have the following performance characteristics.
Attenuation: 0.25dB-0.50dB, for >97% of samples.
Return Loss: 35dB
According to IEC, Grade B connectors have the following performance characteristics
Attenuation: 0.12dB-0.25dB, for >97% of samples.
Return Loss: 45dB
Grade A connector performance (which is still yet to be officially ratified by IEC) has the following performance characteristics. Average Insertion loss of 0.07dB (randomly mated IEC Standard 61300-3-34)and a Maximum Insertion Loss of 0.15db max, for >97% of samples.
While the return loss using IEC 61300-3-6 Random Mated Method is >55dB (unmated–only angled connectors) and >60dB (mated), this performance level is generally available for LC, A/SC, SC and E2000 interfaces.
How are Grade A Connectors on Optical Fiber Patch Cords Identified?
Grade A fiber optic patch cords are identified with the letter ‘A’ printed on the connector side. The symbol is actually the letter ‘A’ enclosed within a triangle (“A”).
This identification marker is proof that you are using a high quality fiber optic patch cord. Grade A connectivity is also available for Optical fiber through adapters. The same rule applies for A grade fiber optic Adapters which also have the letter “A” clearly marked.
What Does a Fiber Optic Patch Cord Meet the Grade A Criteria?
Firstly a high quality Grade A fiber optic patch cord begins with using high quality zirconia ferrules and high quality optical fiber cable. However, the manufacturing and testing process must be first class.
In order to meet the stringent performance criteria of ‘A’ Grade connectors on patch cords, high quality manufacturing, inspection, testing and Quality Assurance (QA) procedures are required. Without the proper expertise in optical fiber technology, many other manufacturers are unable to meet these requirements.
To consistently achieve ‘A’ Grade performance, high accuracy testing using state of the art test equipment as well as constantly assessing testing methods are all required. Analysing and ensuring mechanical end face limits and that parameters are within range, ensures that Grade A connectivity is achieved.
Grade A connectors offer virtually the same IL performance as a fusion splice, with the added benefit of providing a physical contact which can be connected, disconnected and moved when required.
Conclusion
It is important to fully understand the benefits of using reliable, good quality optic fiber patch cords and connectivity. Good quality connectors with low Insertion Loss will meet large bandwidth and high speed requirements of the latest active optical equipment allowing large streams of data to be transmitted reliably over long distances. Grade A connectors on optical fiber patch cords are an example of the advances in this technology.

24-Port Gigabit Switch Selection

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An Ethernet switch acts as a bridge to connect different parts of a network together. Although many routers also possess the network switching capabilities and multiple Ethernet ports, the Ethernet switch is not the replacement for routers. It is worth emphasizing that Ethernet switches are smarter than routers in that they operate at the data link layer (Layer 2) and the network layer (Layer 3) of the OSI Reference Model and therefore support any packet protocol. Ideally, switches will make better use of bandwidth if you prefer wired to wireless connections but have more devices than available Ethernet ports. On the other hand, an Ethernet switch is a costly way to expend the network in home or small business. So it is very important to invest an Ethernet switch with the appropriate number of ports to fit your needs. In the midst of various Gigabit Ethernet switches, a 24-port switch is considered as the most common Gigabit switch that connect devices in a local area network. Then this article will explore how to select a suitable 24-port Gigabit switch.
Cisco SGE2000P comes with 24 10/100/1000BASE-T RJ45 ports and 4 shared Gigabit SFP slots. This 24-port Gigabit managed switch can provide ACL (access control lists), DoS (denial-of-service), VLAN and IEEE 802.1X port authentication. And the enhanced quality of service (QoS) and traffic-management features help ensure clear and reliable voice and video communications. This Gigabit network switch enable you to take advantage of the comprehensive feature set for a better-optimized, more secure network.
TP-Link TL-SG1024 24-Port Gigabit Switch
The TP-Link TL-SG1024 features 24 Gigabit Ethernet ports and non-blocking switching, which can provide large file transferring and also be compatible with 10Mbps and 100Mbps Ethernet devices. Moreover, this network switch has 48Gbps switching capacity with 8K MAC address table, 10KB Jumbo Frame and 4MB buffer memory. This TP-Link switch is a fanless rack mount design with LED diagnostic lights, so you can easily tell which ports are in use. It can automatically adjust power consumption according to the link status to limit the carbon footprint of your network. The price is $69.99 on Amazon. So this fanless Ethernet switch is good for your wallet both because it is inexpensive to buy and because of its energy-saving technology.
Comparison of 24-Port Gigabit Switch
From the chart we can see, all the Gigabit switches listed above provide 24 port Ethernet RJ45 ports, only fiber-mart S3800-24F4S 24-port Gigabit switch has 4 SFP+ uplink ports. They have some characteristics in common that make them suitable for being used in places like home or small business office. In terms of the power consumption, TP-Link TL-SG1024 and NETGEAR ProSafe GS724T are lower than others, but the huge price spread exists between these two switches because NETGEAR ProSafe GS724T has another two SFP ports for more flexible application. Among these four switches, if you have no limited cost budget, fiber-mart S3800-24F4S is a good choice. It has more flexible port combination and higher switching capacity, that is why it may cost a little more than the other three switches. If you need stronger data transferring capability, fiber-mart S3800-24F4S is a better choice considering its forwarding rate. On the contrary, TP-Link TL-SG1024 is the best budget choice. If you want a fanless switch, NETGEAR ProSafe GS724T is an inexpensive and reliable choice, but the install program only works on Windows and the secure management is very difficult to be enabled.
Conclusion
When choosing a Gigabit Ethernet switch, the first factor to consider is how many devices need to be networked together. Purchasing a network switch with too few ports and not enough capacity will prove ineffective, and one that is too large can be a waste of money. Generally, small offices with a few employees should start with a 16-port switch, but a business that is looking to expand its operations soon needs a 24-port switch. So 24-port Gigabit switch is the most future-proofing and cost-effective choice in small business network.

 

Understanding GPON OLT / ONU / ONT SFP Module

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Since the advances in Ethernet technology, “last mile” connectivity is expected to realize between the network backbone and local area networks (end users). Gigabit Passive Optical Network (GPON) is a cost-effective point-to-multipoint access network, which brings great improvement in data transmission distance (up to 20km) and bandwidth (an downstream capacity of 2.5Gbit/s and an upstream capacity of 1.25Gbit/s ). However, GPON’s higher bandwidth and split ratios are only achievable by using GPON-capable optical transceivers. It is well positioned to help meet the needs for higher bandwidth in FTTx applications, and continues to fuel growth in demand for GPON SFP modules. So this article will introduce the basics of GPON SFP, including GPON OLT, GPON ONU and GPON ONT SFP module.
GPON SFP is a new higher-speed bi-directional optical transceiver, which can deliver 2.5 Gbits/sec of bandwidth. And it is a kind of single fiber transceiver which comes with SC connector and can transmit data up to 20km. In addition, it features a 28-dB optical loss budget to enable 1:64 split ratios and provides adequate optical loop lengths. Most EPON and some BPON systems deployed today use 25-dB optics, which limit the split ratio and loop length. For this reason, GPON transceiver enjoys the added advantage of industrial demand. The key performance advantage is to reduce the upstream split loss arising from utilizing the mode-coupled-receivers (MCR) in a PON application. Moreover, this innovative module dose not outweigh the costs over a standard module. For these two reasons, the GPON SFP modules are very attractive to the network operators to improve the utilization of GPON network. On top of that, GPON SFP transceiver is an essential part of GPON system which is necessary both for optical network unit (ONU) installed at the subscriber’s premises and for the optical line terminal (OLT) at the central office (CO). The following part will respectively introduce the GPON OLT, GPON ONU and GPON ONT SFP module.
GPON OLT SFP Module
GPON OLT SFP is designed for OLT side in GPON network. OLT is a equipment integrating L2/L3 switch function, which is located in central office (CO). The main function is to control the information float in both directions: upstream and downstream. The GPON OLT module plays an inevitable role in the upstream and downstream transmission. In order to put across the transmission process, the downstream transmission is taken as an example. A single mode optical fiber coming from OLT (at the central office) PON port, runs to the passive optical splitter (POS) located near end users. And then the optical splitter will divide signals into separate paths which can provide service up to 64 end users. In this basic GPON topology, a GPON OLT module is used to connect a single-mode fiber patch cable to a passive optical splitter. Therefore, GPON OLT transceiver works to get the data, voice and video traffic from metro network or from a long-haul network.
GPON ONU/ONT SFP Module
Since the ONU and ONT are deployed at customer’s premises, they are connected to the OLT by means of optical fiber and no active elements are present in the link. In GPON network, the ONU/ONT transceiver is the physical connection between the customer premises and the central office OLT. This type of modules gets the signals from OLT, so they have the opposite characteristic of GPON OLT transceiver, incorporating a high performance 1310nm burst mode DFB transmitter and 1490nm CW mode APD receiver. By being pled into advanced “triple play” (data, voice & video) ONT or ONU equipment (with SFP ports), such as Ethernet switches, routers, DSLAMs or home gateway, ONU/ONT SFP module fits seamlessly into existing communications equipment and provides end users with a smooth upgrade to GPON. Therefore, GPON ONU/ONT SFP module plays an important role in the applications for point-to-multipoint (P2MP) ONT / ONU equipment in GPON network.
Conclusion
GPON SFP transceiver meets the the requirements of FTTx network to accelerate the speed or capacity. GPON OLT, ONU and ONT SFP module have their respective roles to play in the GPON networks. Many people may worry the high attenuation losses from optical splitter in the GPON networks, as above mentioned, the GPON optical module is just used to solve this problem in that it utilizes the MCR technology that protects large numbers of signals. In a word, this new module is a compelling network alternative to save cost and increase bandwidth and security.

 

MTP/MPO Fiber Cable and its Application in 40G Network

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As the request for greater bandwidth and higher-density fiber optic connections within data centers continues, these requirements must be met by choosing the right type of connectivity. MPO/MTP fiber cable is specially designed for applications for all networking and device needs like 40G modules. It uses a high-density multi-fiber connector system built around precision molded MT ferrule, which are available in UPC and APC polish. It supports both multimode and single-mode applications, and optional lengths available. There are two main MTP/MPO cables types: MPO/MTP trunk cables and MPO/MTP harnesses cables. The following article will have a brief introduction to them individually.
MPO/MTP Standard Trunk Cables
Available in 12, 24, 48 and 72 fibers, MPO/MTP trunk cables work as a permanent link that connects MPO/MTP modules to each other. These cables are used to facilitate rapid deployment of high density backbone cabling in data centers and other high fiber environments reducing network installation or reconfiguration. A 72-fiber MPO/MTP trunk cable (see in the below image) can be terminated with 6 MPO/MTP connectors which are manufactured specifically for multi-fiber loose tube or ribbon cable. The MPO/MTP Trunk cable is designed for Data Center Applications.
72fiber-om4
These cables can interconnect cassettes, panels or redized MPO fan-outs, allowing for the flexibility in case any decision is made to change the connector style in the patch panels, new cassettes can be installed with the new connector style on the cross-connect side of the patch panel without having to change the connector on the cable trunk.
fiber-mart.COM offer single-mode (OS2) and multimode (10G OM3, 10G OM4) MPO/MTP Cable. Single-mode MPO/MTP cable is primarily used for applications involving extensive distances, 10G MPO/MTP cable provide 10G data transfer speeds in high bandwidth applications and they are 5 times faster than standard 50um fiber cable. Work with both VCSEL laser and LED sources, that means, the MTP/MPO trunk cables also provide 40G/100G MPO/MTP trunk cable.
MPO/MTP Harnesses Cables
The MPO/MTP Harnesses cable is MPO/MTP on one end, with single-fiber connectors on another end, single-fiber connector interface available in SC, ST, LC, MTRJ in forms of simplex or duplex channeling. It provides a reliable, cost-effective cabling system for migrating from legacy 10G to higher speed 40G/100GbE. They are suitable for many device needs like 100G modules, including CFP, CFP2 and CFP4 series. MPO/MTP Harnesses cable are available in SM (OS2), MM (OM3/OM4). You could select the suitable fiber according to your own needs with the selection of 12/24/72 fiber cores. The following picture shows the OS2 Fiber Optic Harness Cable.
single-mode-fiber-optic-harness-cable
The MPO/MTP harnesses cable application for data centers requiring quick infrastructure deployment with extended reach that want to maintain bandwidth throughout the infrastructure, its design cater for up-scaling needs and future technologies growth, it’s the best solution, which covers all fiber optic cabling needs in all areas of Data Center.
High-density MTP/MPO Cables for 40G Connection
IEEE 802.3ba 40 Ethernet Standard was ratified in June 2010. This standard specifies MPO connectors for standard-length MMF connectivity. MMF employs parallel optics using MPO interconnects for 40GbE transmission. More specifically, 40G is implemented using eight of the twelve fibers in a MPO connector. Four of these eight fibers are used to transmit while the other four are used to receive. Each Tx/Rx pair is operating at 10G.
Figure 1 shows a Type B MTP female trunk cables for 40GBASE SR4 QSFP+ and multi-fiber migration networks.
mtp-mpo-trunk-cables-in-40g-connectivity
Figure 2 shows how to extend your Cisco Nexus 10GBASE-LR networks up to 40G with MTP cable and 4x10GBASE-LR SFP+ transceiver for your high speed data center solution. The 4x 10GBASE-LR SFP+ transceivers interconnection with 1x 40GBASE-LR QSFP+ transceivers (QSFP-40GE-LR4) by one MTP to 4LC harness cable directly.
mtp-mpo-harness-cable-in-40g-connection
Fiberstore MPO-based fiber cabling solutions provide a fast, simple and economical way for 40G applications. Certainly, 40G fiber cabling solutions are not only limited to MPO/MTP fiber cables. QSFP cables, especially direct attach copper cables are also recommended. 40G direct attach cable provides a cost-effective solution for high-density network connectivity. You can see the detailed information in an article entitled “40G Direct Attach Cable (DAC) Cables Ovrview”.
Conclusion
To sum up, MPO/MTP cabling have proven to be an excellent solution for delivering 10G, 40G and 100G transmission, especially within a data center environment. It provides a flexible, high density option for quickly connecting services. fiber-mart.COM offers various high-density MPO/MTP fiber optic cables, trunk and harness versions, patch cords, and cassette module. The MPO/MTP fiber cables are tested with guaranteed quality, and they can be installed easily, which saves time and money. Besides MPO/MTP cables, other cables are also supplied, like LC to ST fiber cable, LC SC cable, SC SC fiber cable, and so on.