Archive | July 2016

High-quality Cisco Compatible GLC-LH-SM

The Cisco GLC-LH-SM optical transceiver, as one type of SFP transceivers, presents a huge change in the ease of incorporating fiber optic technology into enterprise networking. SFP transceiver does not need to be configured to begin function, and offers internal calibration to optimize data throughput. And, being hot swappable, it can be assured that other network components would keep online during the replacement of the SFP transceivers. Cisco GLC-LH-SM is 1000BASE-LX/LH SFP, which is widely used in optical network systems. High-quality Cisco Compatible GLC-LH-SM is offered only $7 at Fiberstore. Here is what you need to know about Cisco GLC-LH-SM.

Features of GLC-LH-SM

Cisco GLC-LH-SM is the 1000BASE-LX/LH SFP compatible with the IEEE 802.3z 1000BASE-LX standard. Unlike other Cisco SFP transceivers that can operate either on single mode or multimode fibers, GLC-LH-SM can support on standard single mode fiber-optic with a link span of up to 10 km and up to 550 m on any multimode fibers. This industry-standard Cisco Small Form-Factor Pluggable (SFP) is a hot-swappable input/output device that plugs into a Gigabit Ethernet port or slot, linking the port with the network.


The GLC-LH-SM, can be used and interchanged on a wide variety of Cisco products and can be mixed in combinations of 1000BASE-SX, 1000BASE-LX/LH, or 1000BASE-ZX on a port-to-port basis Cisco Catalyst 6500 or 7600 Series Supervisor Engine 720.

Advantages of Cisco GLC-LH-SM Optics

Generally speaking, widespread adoption of fiber optic networking has been extremely high precision demands and delicate construction that came along with the media; but fiber optic cables made of glass-like material can easily damage. Also, the interfaces on either end of the cable have often been required to be very expensive, highly complex transceivers that required a large amount of intricate configuration to perform optimally, which becomes the main obstacle of the widespread adoption of fiber optic networking.

However, with Cisco GLC-LH-SM fiber optic transceivers, the challenges are a thing of the past. Here are three ways that the GLC-LH-SM transceivers make fiber optic networking very possible.

1. There is no need for Cisco SFP transceivers to configuring before function, and it also offers internal calibration to optimize data throughput.

2.  Another unique advantage of fiber optics is that these SFP transceivers are truly hot swappable, which means a transceiver failure can be solved by simply replacing a new one, then you network is back online and ready to go.

3. GLC-LH-SM fiber optics also has a single or multimode operations. Single mode allows data transmission over distances exceeding 10km, useful for very large research facilities, hospitals, or university campuses. And multimode fibers open the data floodgates, giving you maximum throughput upwards of 1.25 Gbps so that this transceiver can meet your needs whether a network solution that covers a long distance, or the huge bandwidth fiber optic.

FS.COM Compatible Cisco GLC-LH-SM Optics

FS.COM is a professional OEM supplier of optical communication products. For the past decade, we have led the industry in manufacturing and delivering world-class products that improve the way we communicate. Cisco compatible GLC-LH-SM is offered at the minimum price of $7 in FS.COM, which is much lower than that in Amazon ($34).


FS.COM 1000BASE-LX/LH SFP can be used in Gigabit Ethernet, Fibre Channel, switch to switch interface, switched backplane applications, router or server interface and other optical transmission systems. Besides the compatible 1000Base-LX/LH SFP modules, we also provide the 1000BASE-EX (like Cisco GLC-EX-SMD), 1000BASE-SX (like Cisco GLC-ZX-SM), 1000BASE-BX (like Cisco GLC-BX-D) and so on.


Fiber optic technology has been around for several decades now, and is sure to be the future transmission media for network backbone and other high-demand applications. Cisco GLC-LH-SM, as an old established Cisco SFP transceivers, wins large market share in telecom field. Cisco GLC-LH-SMD is a new type of GLC-LH-SM with a added function of DOM, which you can also buy it from the market.

Difference Between Twisted Pair Cable and Coaxial Cable

A wire or cable is an indispensable element in communication system for connecting optical devices like optical transceivers, router and switch. Recently the most common cable types deployed in communication system are fiber optic cable, twisted pair cable and coaxial cable. Both twisted pair cable and coaxial cable are copper cables, so what’s the difference between them? This article may help you sort it out.

Twisted Pair

Twisted pair cables as the names implies, consists of a pair of cables twisted together, which has been utilized in telecommunication field for a long time. The twisting can avoid noise from outside sources and crosstalk on multi-pair cables, so this cable is best suited for carrying signals. Basically, twisted pair cable can be divided into two types: unshielded twisted-pair (UTP) and shielded twisted-pair (STP).


UTP is for UNshielded, twisted pair, while STP is for shielded, twisted pair. UTP is what’s typically installed by phone companies and data communication (though this is often not of high enough quality for high-speed network use) and is what 10BaseT Ethernet runs over. However, STP distinguishes itself from UTP in that it consists of a foil jacket which helps to prevent crosstalk and noise from outside source. It is typically used to eliminate inductive and capacitive coupling, so it can be applied between equipment, racks and buildings.

Coaxial Cables

Coaxial cable is composed of an inner solid conductor surrounded by a paralleled outer foil conductor that is protected by an insulating layer. A coaxial cable has over 80 times the transmission capability of the twisted-pair. Coaxial cable has also been the mainstay of high speed communication and has also been applied to network with 10 Gigabit links data centers, because it is proved to be cost efficient for short links within 10 m and for residential network.

coax cable

Comparison Between Twisted Cable and Coaxial Cable

Most people now are quite familiar with what coaxial cables are, as they are used in almost every home for cable television connections. These data cables are also popular in local area networks (LAN) because they are highly resistant to signal interference, which also gives coax cables the ability to support longer cable lengths between two devices.

The biggest advantage of twisted cables is in installation, as it is often thinner than coaxial cables and two conductors are twisted together. However, because they are thinner, they can not support very long runs. These tightly twisted designs cost less than coaxial cables and provide high data transmission rates. They connect with the RJ45 connector, which looks similar to a telephone jack but is designed for twisted pair pins.

In the end, twisted pair cabling is better suited when cost and installation are an issue and if EMI and crosstalk are not too much of a problem. But for coaxial cable, it supports greater cable lengths, and can be shielded in a variety of ways—with a foil shield on each conductor, a foil or braid inside the jacket or a combination of individual conductor and jacket shielding.

Additional Information About Fiber Optic Cables

Besides Twisted and coaxial cables, here comes a new generation of transmission media—fiber jumper. Fiber optic cables have a much greater bandwidth than metal cables, which means they can carry more data. They are also less susceptible to interference. For these two reasons, fiber optic cables are increasingly being used instead of traditional copper cables despite that they are expensive. Nowadays, two types of fiber optic cables are widely adopted in the field of data transfer—single mode fiber optic cables and multimode fiber optic cables.

LC-SC fiber patch cable

Single mode optical fiber is generally adapted to high speed, long-distance applications. While a multimode optical fiber is designed to carry multiple light rays, or modes at the same time, which is mostly used for communication over short distances. Optical fiber cables are also available in various optical connectors, such as LC to SC patch cord, LC to ST fiber cable, SC FC patch cord, etc. The picture above shows a LC to SC patch cord.


Some engineers confirm that fiber optic cables is sure to be the dominant transmission media in telecommunication field, while others hold that copper cables will not be out of the stage. Thus, whether to choose fiber optic cables, twisted cables or coaxial cables, it is advisable for you to have a full understanding of your application before selecting these data cables. All types of Ethernet cables as well as fiber optic cables are provided at FS.COM. Our Quick Order Tool will help you find what you need. If you have any requirement of our products, please send your request to us.

A Quick Lesson in Fiber Optics

Fiber optics, with its high bandwidth capacities and low attenuation characteristics, is considered to be the ideal building equipment in the telecommunication field. Depending on the type of application and the reach to be achieved, various types of optical fiber may be considered and deployed. This article is devoted to provide solutions to the questions about fiber optic cables. After going through the whole passage, you might form a basic understanding of optical cables.

What Is an Optical Fiber?

Core and cladding are the two main elements of an optical fiber. The core as shown in the image below, is the axial part of the optical fiber made of silica glass, which is the light transmission area of the fiber. The cladding is the layer completely surrounding the core. The refractive index of the core is higher than that of the cladding, so that light in the core strikes the interface with the cladding at a bouncing angle, gets trapped in the core by total internal reflection, and keeps traveling in the proper direction down the length of the fiber to its destination.

internal structure of fiber optics

There is usually another layer, called a coating surrounding the cladding that typically consists of protective polymer layers applied during the fiber drawing process, before the fiber contacts any surface. As we all known, the most typical types of fiber optic cable are MM fiber patch cords and single mode fiber optic cables.

How Do Fiber Optics Work?

Fiber optics use light pulses to transmit signals from one end to another. Light passes through the optical cable, bouncing off the cladding until it reaches the other end of the fiber channel, which is called total internal reflection. The diameter of the core corresponds directly with the angle of reflection.

As this diameter increases, the light requires more reflections and a greater amount of time to travel a given distance. For example, single mode fiber optic cable has a smaller diameter core which makes itself suitable for long distance, higher bandwidth runs. Multimode fiber, however, has a larger diameter core and is more commonly used in shorter cable runs.

What You Need to Know About Optical Fiber?

Attenuation and Wavelength

Light is gradually attenuated when it is propagated along the fiber. The attenuation value is expressed in dB/km. It is a function of the wavelength (λ), meaning that the operating wavelength to transmit a signal in an optical fiber is not any wavelength. It corresponds to a minimum of attenuation.

The typical operating wavelengths that light sources have been developed for are 850 nm and 1300 nm in multimode, and 1310 nm and 1550 nm in single mode. For a 850 nm operating wavelength, there is a 3dB light attenuation after 1 km propagation. 3 dB means that half of the light has been lost.


Bandwidth is a measure of the data-carrying capacity of an optical fiber. For example, a fiber with a bandwidth of 500 (Mega-hertz kilometer) can transmit data at a rate of 500 MHz along one kilometer. Bandwidth in single mode fibers is much higher than in multimode fibers.

How to Link Two Optical Fibers?

Fusion Splice

This operation usually needs a fusion splicer to accomplish the process. In this method, optical technician directly links two fibers together by welding with an electric arc, by aligning best possible both fiber cores. Compared with other method, this linking method is fast and relatively simple to make. And the light loss generated by the welding, due to an imperfect alignment of the cores, remains very weak.

However, just as the coin has two sides, this link method has drawbacks. In spite of a protection of fusion by a heat-shrinkable tube, this type of link is relatively fragile. It is a permanent link. What’s worst, the fusion splicer is usually very expensive.

Use of Connectors

In this case, it is necessary to terminate a connector at each end of the fibers to be connected. The two fibers can then be connected by connecting the two connectors together. The following picture shows a SC fiber patch cord.

SC fiber patch cord

Just as the following picture shows, this type of connection is robust. The type of connector can be chosen according to the application field of the system. Unlike fusion splice, this connection is removable. It is possible to connect and disconnect two fibers hundreds to thousands times without damaging the connectors. But the implementation is longer than fusion, and requires an experiment as well as specific tools. Furthermore, the light loss due to connection is higher than in the splicing solution.

Why to Choose Fiber Optics?

The main advantages of fiber optics are the followings:

  • Lower loss: Optical fiber has lower attenuation than copper conductors, allowing longer cable runs and fewer repeaters.
  • Increased bandwidth: The high signal bandwidth of optical fiber provides a significantly greater information-carrying capacity. Typical bandwidths for multimode fibers are between 200 and 600, and > 10 for singlemode fibers. Typical values for electrical conductors are 10 to 25
  • Immunity to interference: Optical fibers are immune to electromagnetic and radio frequency interference and also emit no radiation themselves.
  • No detection: Standard fiber optic cables are dielectric, so they cannot be detected by any type of detector.
  • Electrical isolation: Fiber optics allows to transmit information between two points at two different electrical potentials, and also next to high voltage equipments.
  • Decreased size and weight: Compared to copper conductors of equivalent signal-carrying capacity, fiber optic cables are easier to install, require less duct space, and weight about 10 to 15 times less.


The Internet nowadays is largely based around optical fiber. For those who do not understand fiber optics, they will have confusion and misconceptions when working with fiber optic networks. This article probably will not make you an optical engineer, but it will guide you to touch on a little bit of every topics, from the theoretical to the practical even if you aren’t designing optical networks. FS.COM offers s variety of fiber optic cables with the highest quality and low price. If you are interested, you can contact us.

FBT vs. PLC Fiber Optic Splitters

Optical technology nowadays has made huge progress to meet the growing requirement for high-density multifiber applications in telecommunication field. Fiber optic splitter, as an indispensable equipment for fiber optic network, enables signals on an optical fiber to be distributed among two or more fibers. Optical cable splitter typically can be divided into FBT (Fused Biconical Taper) splitter and PLC (Planar Lightwave Circuit) splitter. Each type has advantages and disadvantages when deploying them in a passive optical network. This article will guide you to form a basic knowledge about fiber optic splitter, especially FBT splitter and PLC splitter.

Fiber Optic Splitter

Optical splitter, also known as a beam splitter, is based on a quartz substrate of an integrated waveguide optical power distribution device, which is used to split the fiber optic light evenly into several parts at a certain ratio. Since splitters contain no electronics nor require power, they are an integral component and widely used in most fiber optic networks. The diagram below shows how light in a single input fiber can split between four individual fibers (1×4).


Optical splitters are manufactured commonly in two types according to its working principle—FBT (Fused Biconical Taper) splitter and PLC (Planar Lightwave Circuit) splitter. Splitters can be built using a variety of single mode fiber patch cables and multimode optical fibers and with most connector types for various applications.

FBT Splitter—FBT is a traditional technology that two fibers are typically twisted and fused together 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, typically 3mm diameter by 54mm long. FBT splitters are widely accepted and used in passive optical networks, especially for instances where the split configuration is not more than 1×4. The slight drawback of this technology is when larger split configurations such as 1×16, 1×32 and 1×64 are needed. The following picture shows a FBT splitter with a split configuration of 1×2.

FBT Splitter

PLC splitter—A PLC splitter is a micro-optical component based on planar lightwave circuit technology and provides a low cost light distribution solution with small form factor and high reliability. It is manufactured using silica glass waveguide circuits that are aligned with a V-groove fiber array chip that uses ribbon fiber. Once everything is aligned and bonded, it is then packaged inside a miniature housing. PLC Splitter has high quality performance, such as low insertion loss, low PDL (Polarization Dependent Loss), high return loss and excellent uniformity over a wide wavelength range from 1260 nm to 1620 nm and have an operating temperature -40°C to +85°C. The following picture shows a PLC splitter connected with LC LC single mode patch cord.

PLC splitter

Advantages and Disadvantages of FBT and PLC splitters
1. FBT—Fused Biconical Splitter

FBT splitter is one of the most common splitters, which is widely accepted and used in passive networks. FBT splitter is designed for power splitting and tapping in telecommunication equipment, CATV network, and test equipment.


  • The product is well-known and is easy to produce, thus reducing cost of production.
    Splitter ratios can be customized.
  • Can work on three different operating bands (850nm, 131 Onm, and 1550nm).


  • Restricted to its operating wavelength.
  • Because of errors in equality insertion loss, the maximum insertion loss will vary depending on the split and increase substantially for those splits over 1:8.
  • Because an exact equal ratio cannot be ensured, transmission distance can be affected.
  • High temperature dependent loss (TDL). The operating temperature range is 23 °F- 167 °F. Any changes in temperature can affect the insertion loss.
  • The larger the split, the larger the encapsulation module.
  • Susceptible to failure due to extreme temperatures or improper handling.

2. PLC—Planar Lightwave Circuit Splitter

PLC splitter is a hot research at home and abroad today, with a good prospect of application, which is used to distribute or combine optical signals. It is based on planar lightwave circuit technology and provides a low cost light distribution solution with small form factor and high reliability.


  • Suitable for multiple operating wavelengths (1260nm–1650nm); unstinted.
  • Equal splitter ratios for all branches.
  • Compact configuration; smaller size; small occupation space.
  • Good stability across all ratios.
  • High quality; low failure rate.


  • Complicated production process.
  • Costlier than the FBT splitter in the smaller ratios.


Similar in size and outer appearance, PLC and FBT splitters provide data and video access for business and private customers, but internally the technologies behind these types vary, thus giving service providers a possibility to choose a more appropriate solution. FS.COM provides a full range of optical fiber splitters for you to choose from. If you are interested, you can have a look at it.