Fiber Optic Attenuators—Types And Applications

A fiber optical attenuator is a fiber-coupled device used to reduce or balance the power (the power level of an optical signal, either in free space or in an optical fiber) of the light transmitted from one device to another device. Fiber optic attenuators are designed to use with various kinds of fiber optic connectors. The basical types of optical attenuators are fixed, step-wise variable, and variable fiber optic attenuator. Insertion loss and return loss, or back reflection, are collectively referred to as attenuation; total attenuation is called system loss.

Fiber Optic Attenuators provide technicians with a means of adjusting an optical signal level. Attenuators are commonly used in fiber optic communications, either to test power level margins by temporarily adding a calibrated amount of signal loss, or installed permanently to properly match transmitter and receiver levels.

Commonly used fiber optic attenuators are the female to male type, which is also called a plug fiber attenuator. Plug fiber attenuators utilize male/female ceramic ferrule connectors. Fixed value attenuators function at one loss level, while variable attenuators like the variable optical attenuated jumper (VOA) can adjust loss in a range, as by a turning screw. Patch cord attenuators are fibers that combine the functions of the patch cord and attenuator, reducing costs.

Types of fiber optic attenuators:
1. Female to male plug style optical attenuator (MU, SC, FC, ST, LC) PC& APC polish available;
2. Flange style fiber optical attenuator;
3. Adjustable fiber optical attenuator (FC style) Attenuation scale:0~30dB;
4. IN-Line style fiber optical attenuator.

Wide range variable & inline fiber optic attenuator
The inline fiber optic attenuators are with more accurate attenuation compared with traditional connector type fiber optic attenuators. What is more, the fiber optic attenuator is with a precision screw set, by turing it, the attenuation range can be varied. And this fiber optical attenuator can be with various terminations on the each side of the cable.

Variable Fiber Optic Attenuators
Fixed value fiber optic attenuators can reduce the power of fiber light at a fixed value loss, for example, a 10dB SC fiber optic attenuator will reduce the optical power 10dB and utilize a SC male to female attenuator. Variable fiber optic attenuators (or adjustable fiber optic attenuator) are with adjustable attenuation range. It usually is inline type, the appearance like fiber optic patch cord; it is with an adjustable component in the middle of the device to change the attenuation level to a certain figure. There are also handheld variable fiber optic attenuators; they are used as test equipment, and we have the inline fiber optic attenuators.

Fiber optic attenuator name is based on the connector type (like lc attenuator) and the attenuation level. For example, LC 5dB fiber optic attenuator means this attenuator use LC fiber optic connector and it can reduce the optical fiber power level by 5dB. Commonly used attenuation range is from 1dB to 20Db. Fiber Optic Attenuators are employed in telecommunications networks, local area networks (LAN), and cable television (CATV) systems. They also can be used in fiber optic sensors, testing instruments, and fiber to the home. Compact, environmentally sound, and suffering low return losses, these devices can be embedded into optical fiber networks fitted to the wide variety of industry standard connectors and fibers.

Fiber Testers Of Fusion Splicer

fusion splicer is a device that uses source of heat to melt two optical fibers together at their end faces, to form a single long fiber. The resulting joint, or fusion splice, permanently joins the two optical fibers end to end, so that optical light signals can pass from one fiber into the other with very little loss. The source of heat is usually an electric arc, but can also be a laser, or a gas flame, or a tungsten filament through which current is passed.

Features of Fusion Splicers:
Carefully engineered fiber clamps allow the precise fixing of the fiber ends. At least one clamp is precisely adjustable with micrometer screws;
For splicing polarization-maintaining fibers, it is also necessary to rotate one of the fibers around its axis;
A microscope allows inspection of quality and alignment of the fiber ends. Often, there is a knob for switching between two orthogonal directions of view. The fiber cores can also usually be seen;
A “prefuse”, applied without touching the fibers, allows one to clean the surfaces;
Some splicers do the alignment automatically based on a camera image and/or on monitoring the optical power throughput. For the latter, there must be a light source attached to one fiber end, and a photodetector for the other one;
Some devices can also measure the quality of the resulting splice.

The process of Fusion Splicing involves using localized heat to melt or fuse the ends of two optical fibers together. The Splicing process begins by preparing each Fiber end for fusion. Fusion splicing requires that all protective coatings be removed from the ends of each fiber. The fiber is then cleaved using the score-and-break method. The quality of each fiber end is inspected using a microscope. In fusion splicing, Splice Loss is a direct function of the angles and quality of the two fiber-end faces.

Before optical fibers can be successfully fusion-spliced, they need to be carefully stripped of their outer jackets and polymer coating, thoroughly cleaned, and then precisely cleaved to form smooth, perpendicular end faces. Once all of this has been completed, each fiber is placed into a holder in the splicer’s enclosure.

Cleaning the splicing device and the fiber
Since the slightest trace of dust or other impurities can wreak havoc on a splice’s ability to transmit optical signals, you can never be too clean when it comes to fusion splicing. Even though fibers are hand-cleaned before being inserted into the splicing device, many fusion splicers incorporate an extra precautionary cleaning step into the process: prior to fusing, they generate a small spark between the fiber ends to burn off any remaining dust or moisture.

The fiber is then cleaved using the score-and-break method so that its endface is perfectly flat and perpendicular to the axis of the fiber. The quality of each fiber end is inspected using a microscope. In fusion splicing, splice loss is a direct function of the angles and quality of the two fiber-end faces. The closer to 90 degrees the cleave angle is the lower optical loss the splice will yield.

Splicing Optic Fiber
The splicer emits a second, larger spark that melts the optical fiber end faces without causing the fibers’ cladding and molten glass core to run together. The melted fiber tips are then joined together, forming the final fusion splice. Estimated splice-loss tests are then performed, with most fiber fusion splices showing a typical optical loss of 0.1 dB or less.

Fiberstore is the recognized leader in the development of the highest quality fusion splicing equipment and accessories that have and continue to advance fusion splicing technology. You have a wide selection of fiber optic splicing relevant equipments, like fusion splicer, fiber optic cleaver, fiber cleaver blades, fusion splicer assemblies, etc.

Economical Fiber Media Converter To Long Distance Transmission

Fiber media converter, also known as fiber transceiver or Ethernet media converter, is a simple networking device which receives data signals, sents via one media, converts the signals and then transmits the signals into another kind of media. A fiber optic media converter makes it possible to connect two dissimilar media types with fiber optic cabling, can transform between different media, different cable types and different equipment interfaces. They were introduced to the industry nearly two decades ago, and are important in interconnecting fiber optic cabling-based systems with existing copper-based and structured cabling systems.

Key Features
Fiber media converters support many different data communication protocols including Ethernet, Fast Ethernet, Gigabit Ethernet, T1/E1/J1, DS3/E3, as well as multiple cabling types such as coax, twisted pair, multi-mode and single-mode fiber optics. Fiber media converters can connect different local area network (LAN) media, modifying duplex and speed settings. Switching media converters can connect legacy 10BASE-T network segments to more recent 100BASE-TX or 100BASE-FX Fast Ethernet infrastructure. For example, existing half-duplex hubs can be connected to 100BASE-TX Fast Ethernet network segments over 100BASE-FX fiber.

Fiber media converters are also used in metropolitan area network (MAN) access and data transport services to enterprise customers. When expanding the reach of the LAN to span multiple locations, fiber transceivers are useful in connecting multiple LANs to form one large campus area network that spans over a wide geographic area.

Media converter types range from small standalone devices and PC card converters to high port-density chassis systems that offer many advanced features for network management.

There are singlemode converters (also called WDM fiber optic converters) and multimode converters. For singlemode converters, there are dual fiber type and single fiber type which the fiber cable functions both as transmitting media and receiving media. While for multimode converters, there are only dual fiber types. Working distance is also different. For typical multimode fiber optic converters, their working distance max is about 2km, for single mode fiber media converters, their working distance can be 20km, 40km, 60km, 80km and up to 120km.

Some fiber optic converters will work with any type of Ethernet cable while others only have ports for either the 100 Megabit or the 10 Gigabit speed Ethernet cables. Different brands and models of converters have different speed caps.

Fiber media converter protects your investment in existing copper Ethernet-based network, is an economical solution to achieve long distance transmission based on current status. With the rapid development of society, the transmission of different types of information, like audio, video and data, has become more and more important and Ethernet has been a good way to deal with this need. Traditional Ethernet fiber converter has its disadvantages because it use copper wires and its working distance is very short (about 100meters). Fiber media converter is the solution of this problem, it could extend the Ethernet working distance to max 100km or more, what is more ,the fiber optical converter used today is cheap and reliable.

CWDM Solutions Provided by Ingellen

CWDM technology involves the applications of CWDM products such as CWDM MUX/DEMUX, CWDM SFP, CWDM add-drop multiplexer and other related products. This article is about what is CWDM stand for, the advantages of CWDM and what devices or products needed for the CWDM solutions.

As we know, broadband has unveiled a new world for subscribers, full of advanced capabilities and faster speeds. Fiber optic connections typically require two strands of fiber – one for transmitting and one for receiving signals. But, what happens when you need to add services or customers, there are three options, 1) installing more cables, 2) increasing system bitrate to multiplex more signals or 3) wavelength division multiplexing. Obviously, the first two selections are all need more investment on the existing systems, which are all not the cost-effective ones. Only the third alternative, WDM (wavelength division multiplexing), allows using current electronics and current fibers and simply shares fibers by transmitting different channels at different color (wavelengths) of the light.

There is Coarse Wavelength Division Multiplexing and Dense Wavelength Division Multiplexing for WDM technology, Coarse Wave Division Multiplexing (CWDM) technology is the most effective solution for expanding bandwidth and has many advantages over DWDM technology in terms of system costs, set-up, maintenance, and scalability.

Coarse wavelength division multiplexing are realized by the used of CWDM modules, which combines or split up to 18 optical signals over one single fiber optic link. Each signal carried can be at a different rate and in a different format. CWDM technology uses an ITU standard 20nm spacing between the wavelengths, from 1310nm to 1610nm. CWDM is coarse wavelength multiplexing technology for city and access networks.

CWDM Modules utilize thin-film coating and micro optics package technology which is available in two main configurations: CWDM Mux/Demux modules and CWDM OADM modules. The CWDM solution we offer has the ability to multiplex up to9 (8+1) different fiber links over the same physical circuit. The operation range can reach up to120Km, depending on optical modules used.The total maximum capacity is 1.25G x 9 =11.25G.

CWDM Solutions by Ingellen
Benefits of CWDM
Passive equipment that uses no electrical power
Much lower cost per channel than DWDM
Scalability to grow the fiber capacity as needed
With little or no increased cost
Protocol transparent
CWDM can provide connectivity for multiple Wireless Carriers using virtually any protocol to the cell tower over a single strand of fiber.

Ingellen provides CWDM modules with various kinds of connectors and cable length and optional stainless tube package or standard box package and to meet your requirement. We offer 2 channel CWDM Mux/Demux, 4 channel CWDM Mux/Demux …up to 18 channel CWDM Mux/Demux modules and 1-16 channels CWDM OADM. Our CWDM modules are configured by number of channels for any customer-specify channel plan, and can be integrated with taps and detectors for a complete CWDM solution. All of these CWDM modules come with compact size, Low Insertion Loss, Bi-directional and Environmentally Independent features.

Multiplexers Used In Communication

A multiplexer, sometimes referred to a multiplexor or simply a mux, is an electronic device that selects from several input signals and transmits to one or more output signals, can be considered as a multiple-input, single-output switch. A Phone Optical Multiplexer is an example of a very large virtual multiplexer that is built from many smaller, discrete ones. An electronic multiplexer makes it possible for multiple signals to share one device or resource, for example, one A/D converter or one communication line, instead of having one device per input signal.

Multiplexers connect or control, multiple input lines called “channels” consisting of either 2, 4, 8 or 16 individual inputs, one at a time to an output. A multiplexer is often used with a complementary demultiplexer on the receiving end. A demultiplexer (or demux) is a single-input, multiple-output switch. At the receiving end, a demux, chooses the correct destination from the many possible destinations by applying the same principle in reverse.

Generally, multiplexers are used as one method of reducing the number of logic gates required in a circuit or when a single data line is required to carry two or more different digital signals. It selects one of many analog or digital input signals and forwards the selected input into a single line. A multiplexer of 2n inputs has n select lines, which are used to select which input line to send to the output.

Multiplexers also are used in building digital semiconductors such as central processing units (CPUs) and graphics controllers. In these applications, the number of inputs is generally a multiple of two, the number of outputs is either one or relatively small multiple of two, and the number of control signals is related to the combined number of inputs and outputs.

Types of multiplexers are used in communications. In its simplest form, a multiplexer will have two signal inputs, one control input and one output. One example of an analog multiplexer is the source control on a home stereo unit that allows the user to choose between the audio from a compact disc (CD) player, digital versatile disc (DVD) player and cable television line.

There are some more complex forms of multiplexers. Time-division multiplexers(or TDM), for example, have the same input/output characteristics as other multiplexers, but instead of having control signals, they alternate between all possible inputs at precise time intervals. Alternatively, a digital TDM multiplexer may combine a limited number of constant bit rate digital data streams into one data stream of a higher data rate, by forming data frames consisting of one timeslot per channel. Time-division multiplexers generally are built as semiconductor devices, or chips, but they also can be built as optical devices for fiber optic applications.

PDH Multiplexer designs for highly integrated structure and provides 16 standard E1 interfaces together with one channel of order wire, with self-contained alarm and NM functions, as well as self-testing and E1 loop-back testing functions. While, digital multiplexer is constructed from individual analogue switches encased in a single IC package as opposed to the “mechanical” type selectors such as normal conventional switches and relays.