0
Want this question answered?
Be notified when an answer is posted
Add your answer:
Earn +20 pts
What is the effect when a 1310nm optical module is fed wit a 1550nm optical source and vice-versa?
When I Google for "1310nm optical module", I find devices that generate and put out narrow pulses of light at 1310 nm. When I Google for "1550nm optical source", I find devices that generate a constant beam of light at 1550 nm. Is that what this question is about, or are you talking about some other kind of "1310 nm optical module" ? Neither of these devices needs to be "fed" any light. What happens if you hook them up anyway?
What is short haul and long haul in stm1 surpass?
short haul in stm1 is below 30km and long haul which works for more then 30km.. there are differenet equipments for short haul and long haul.. working different wavelenght. long haul can work one 1310 nm and 1550nm.. but short haul can work on 1310 nm only..
What is the single mode fiber optic?
Single Mode cable is a single stand (most applications use 2 fibers) of glass fiber with a diameter of 8.3 to 10 microns that has one mode of transmission. Single Mode Fiber with a relatively narrow diameter, through which only one mode will propagate typically 1310 or 1550nm. Carries higher bandwidth than multimode fiber, but requires a light source with a narrow spectral width. Synonyms mono-mode optical fiber, single-mode fiber, single-mode optical waveguide, uni-mode fiber.
What is C band and L band in WDM?
WDM (Wavelength Division Multiplexing ) is a transmission technology that uses one optical fiber to simultaneously transmit multiple optical carriers of different wavelengths. The transmission loss in optical fiber varies with the wavelength of light. In order to reduce loss as much as possible and ensure transmission effect, it is necessary to find the most suitable wavelength for transmission. After a long time of exploration and testing, light in the wavelength range of 1260nm~1625nm has the lowest signal distortion and loss caused by dispersion, and is most suitable for transmission in optical fiber.(glsun dot com) The wavelength applications of optical fibers are divided into several bands, and each band is used as an independent channel to transmit an optical signal of a predetermined wavelength. ITU-T divides the frequency band of single-mode optical fiber more than 1260nm into several bands: O, E, S, C, L and U. O Band O band is the original band with wavelength range 1260-1360 nm. O band is the first wavelength band historically used for optical communication, with minimal signal distortion (due to dispersion). E Band E band is the extended band with wavelength range 1360-1460 nm. It is the least common of these wavebands. E band is mainly used as an extension of O band, but its use in optical communications is limited mainly because many existing optical cables show high attenuation in E band and the manufacturing process is very energy intensive. S Band E band is the short wavelength band with wavelength range 1460-1530 nm. Fiber loss is lower in S band than in O band, and S band is used by many PON (passive optical network) systems. C Band C band is the conventional wavelength band with wavelength range 1530-1565 nm. Optical fiber has the lowest loss in C band and has a great advantage in long distance transmission system. EDFA technology is commonly used in many metropolitan, long-distance, ultra-long-distance and subsea optical transmission systems in combination with WDM. The use of C band has expanded with the advent of DWDM (Dense Wavelength Division Multiplexing), which enables multiple signals to share a single optical fiber. L Band C band is the long wavelength band with wavelength range 1565-1625 nm. It is the second lowest-loss wavelength band and is often used when C band is insufficient to meet bandwidth requirements. With the widespread availability of EDFA, DWDM systems have expanded up to L band and were initially used to expand the capacity of terrestrial DWDM optical networks. Now it has been brought in by undersea cable operators to do the same thing - expand the total capacity of undersea cables. U Band Because the transmission attenuation loss of C band and L band is the lowest, the signal light in DWDM system is usually selected to be at C band and L band. In addition to O band and L band, there are two other bands, namely the 850 nm band and the U band (ultra-long band: 1625-1675 nm). The 850 nm band is the main wavelength of multi-mode fiber communication system combined with VCSEL (Vertical cavity surface emitting Laser). U band is mainly used for network monitoring. Summary WDM technology can be divided into WDM, CWDM and DWDM according to different wavelength modes. The wavelength range stipulated by ITU for CWDM (ITU-T G.694.2) is 1271 to 1611 nm, but in application, considering the large attenuation of 1270-1470nm band, the band range of 1470~1610nm is usually used. DWDM channels are more densely spaced and use C-band (1530 nm-1565 nm) and L-band (1570nm-1610nm) transmission Windows. Ordinary WDM generally uses 1310 and 1550nm wavelengths. With the growth of FTTH applications, C band and L band, the most commonly used bands in fiber optic networks, will play an increasingly important role in optical transmission systems.
What is the difference between dual fiber single mode and dual fiber multi mode?
There are 2 major differences one color code. single mode will be white or yellow. multimode will be black or tan. 2nd the hole in the connector ferrel for the fiber. fiber is 125 microns. in a single mode connector the opening is 126 microns. multimode is 127/128.Single Mode cable is a single strand (most applications use 2 fibers) of glass fiber with a diameter of 8.3 to 10 microns that has one mode of transmission. Single Mode Fiber with a relatively narrow diameter, through which only one mode will propagate typically 1310 or 1550nm. Carries higher bandwidth than multimode fiber, but requires a light source with a narrow spectral width. Synonyms mono-mode optical fiber, single-mode fiber, single-mode optical waveguide, uni-mode fiber.Single Modem fiber is used in many applications where data is sent at multi-frequency (WDM Wave-Division-Multiplexing) so only one cable is needed - (single-mode on one single fiber)Single-mode fiber gives you a higher transmission rate and up to 50 times more distance than multimode, but it also costs more. Single-mode fiber has a much smaller core than multimode. The small core and single light-wave virtually eliminate any distortion that could result from overlapping light pulses, providing the least signal attenuation and the highest transmission speeds of any fiber cable type.Single-mode optical fiber is an optical fiber in which only the lowest order bound mode can propagate at the wavelength of interest typically 1300 to 1320nm.Multi-Mode cable has a little bit bigger diameter, with a common diameters in the 50-to-100 micron range for the light carry component (in the US the most common size is 62.5um). Most applications in which Multi-mode fiber is used, 2 fibers are used (WDM is not normally used on multi-mode fiber). POF is a newer plastic-based cable which promises performance similar to glass cable on very short runs, but at a lower cost.Multimode fiber gives you high bandwidth at high speeds (10 to 100MBS - Gigabit to 275m to 2km) over medium distances. Light waves are dispersed into numerous paths, or modes, as they travel through the cable's core typically 850 or 1300nm. Typical multimode fiber core diameters are 50, 62.5, and 100 micrometers. However, in long cable runs (greater than 3000 feet [914.4 meters), multiple paths of light can cause signal distortion at the receiving end, resulting in an unclear and incomplete data transmission so designers now call for single mode fiber in new applications using Gigabit and beyond.More Information:Multimode and Singlemode fiber are the five types of fiber in common use. Both fibers are 125 microns in outside diameter - a micron is one one-millionth of a meter & 125 microns is 0.005 inches- a bit larger than the typical human hair. Multimode fiber has light travelling in the core in lots of rays, called modes. It's a bigger core (always 62.5 microns, but sometimes 50 microns) & is used with LED sources at wavelengths of 850 & 1300 nm for slower local area networks (LANs) & lasers at 850 & 1310 nm for networks jogging at gigabits per second or more. Singlemode fiber has a much smaller core, only about 9 microns, so that the light travels in one ray. It is used for telephony & CATV with laser sources at 1300 & 1550 nm. Plastic Optical Fiber (POF) is large core (about 1mm) fiber that can only be used for short, low speed networks.Step index multimode was the first fiber design but is slow for most makes use of, due to the dispersion caused by the different path lengths of the various modes. Step index fiber is rare - only POF makes use of a step index design today.Graded index multimode fiber makes use of variations in the composition of the glass in the core to compensate for the different path lengths of the modes. It offers hundreds of times more bandwidth than step index fiber - up to about 2 gigahertz.Singlemode fiber shrinks the core down so small that the light can only travel in one ray. This increases the bandwidth to infinity - but it is practically limited to about 100,000 gigahertz.
What are the three categories of data communication?
Fiber Types & Modes of TransmissionIn fiber optics, the term "mode" refers to a stable propagation state of light down the fiber. Fibers can have any number of stable propagation states (modes), giving rise to two basic types of optical fibers, multimode and singlemode. Multimode obviously refers to a fiber that has many modes of propagation, while a singlemode, by design, only has one. Whether a particular fiber is multimode or singlemode depends on the fiber geometry, core/clad refractive indices, and the wavelength of operation. Multimode fibers can be further broken down into two subcategories, step-index and graded-index. Each type has distinctive advantages and disadvantages, which will be discussed below in more detail.Step-Index Multimode Fiber This was the first fiber type to find practical application, and continues to be in wide use today. A step-index multimode fiber allows the light to travel at many different angles within the fiber, thereby allowing many modes of propagation. The term "step" refers to the step function the refractive index takes at the core/clad interface.The advantages of a step-index multimode fiber are related to the relatively large core area and high numerical apertures. Both of these properties allow light to be easily coupled into the fiber. In turn, this allows the use of inexpensive termination techniques, low cost diodes, and high power handling capability. These fibers are therefore widely used in high power laser delivery applications (medical procedures, material processing), industrial process control links (factory automation), short distance data communications, and fiber sensors.A disadvantage to step-index multimode is bandwidth. Referring to the figure, the path the light takes down a step-index multimode fiber will be longer or shorter depending on the angle of propagation. This difference in path length causes the pulse of light to spread out during its journey down the fiber. This is known as modal dispersion (see Dispersion section). As one pulse spreads, it eventually interferes with the neighboring pulses, distorting the transmission signal. The longer the fiber length, the more severe this pulse spreading will become. However, this is only a problem in applications that require a coherent signal, as in communications links. Power delivery or sensor systems do not require coherent transmission and many data communication or industrial process control links are relatively short distances (less than 2km), allowing the widespread use of step-index multimode fiber.There is a wide selection of step-index multimode fiber available. Sizes vary from ~50 to >2000µm core diameters. Their construction can be silica or plastic cladding using silica, plastic, or liquid as a core. There are also applications with no core called hollow waveguides. The silica constructions allow lower attenuation, greater spectral range, higher power handling capability, and greater environmental range. Plastic fibers offer lower cost and greater flexibility, but are limited in transmission and environmental properties. Hollow waveguides are used principally in the IR.Polymicro offers a wide selection of step-index, multimode fibers, particularly for laser power delivery and stringent or harsh environmental conditions. Please refer to our data sheets.Graded-Index Multimode Fiber As the name implies, the refractive index of this fiber gradually decreases from the core out through the cladding, as opposed to the abrupt step change of step-index. Instead of taking a zigzag path down the fiber, the gradual change in refractive index directs the light in a sinusoidal path as previously illustrated. Since the light travels faster in a material of lower refractive index, the light traveling on the outer reaches of the graded region moves more quickly, thereby reducing the amount of pulse spreading. The result is a dramatic >25-fold increase in bandwidth over step-index multimode fibers.Graded-index is actually a compromise between step-index multimode and singlemode fibers, trading off bandwidth for ease of termination and light launch. The graded profile and smaller core increases bandwidth over step-index multimode, but the core sizes are still large enough for convenient termination and use of lower cost diodes. In more recent years, the components and techniques for terminating singlemode has improved dramatically, so graded-index has seen a decline in market share. However, graded-index remains a popular standard for use in medium distance (2-15km) data communication links.The most common core sizes for graded-index multimode fibers are 50, 62.5, and 100mm. These sizes have become industry standards. The construction is always silica core/silica clad based, with dopants (typically Ge, B, P, and F) used to adjust the refractive index in the graded profile. This fiber is used almost exclusively for medium distance data communication (local area networks), although it is sometimes used for fiber sensor systems. The smaller core area makes this fiber less useful for power delivery applications, however new special, larger core designs specifically for high power applications are available.Singlemode Fiber In singlemode fiber the core size is reduced to the point (5-10mm diameter) where only one mode, the primary mode, can be guided. This mode essentially travels straight through the fiber and thus is not subject to the pulse spreading seen in multimode fiber due to different path lengths. The net effect is a substantial increase in bandwidth since all the light is traveling at the same speed for the same distance. In addition, using the primary mode and higher operational wavelengths (1310 and 1550nm) results in very low attenuation. For these reasons, singlemode is the fiber of choice for long distance data and voice communication.Singlemode does experience some distortion of the signal, but this is due primarily to chromatic dispersion, which is variation in light speed due to the pulse not being purely monochromatic. This type of dispersion is very small when compared to the modal dispersion experienced in multimode fibers.Singlemode fiber typically consists of a silica core/silica clad construction with a step-index refractive index profile. The core and/or clad is doped to obtain the index difference between the core and clad. The core size, being very small, is more difficult and costly to terminate versus the multimode fibers, but for long distance systems this cost is acceptable. In contrast, the small core size does not allow a great deal of power input, and therefore this fiber is generally not suitable for power delivery and many sensor applications.
