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Solid vs Stranded Cable – Which one should i Choose?

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If you are on the fence as to whether you should use solid vs stranded cable, you are not alone. People all around the world struggle with this decision and there are no clear cut answers. The best option for you hinges on the nuances of your particular situation. Let’s take a look at the differences between the two types of cables and examine instances where one will function better than the other.
Solid vs Stranded Cable: The Basics
Solid cable is built with one strand or the core of a wire that has non-conductive material for insulation. This type of cable is used for home electrical wiring, wiring for breadboards and other situations where wires are not required to be constantly flexed. Stranded cable is made up of a collection of small gauge wires that are insulated and compressed with materials that are non-conductive. This type of cabling is typically used in situations where wire must be routed into cramped spaces. It is also used in areas where there is considerable flexing or vibrations. Examples include speaker wire, headphone cables and appliance cables.
Situations Where Stranded Cables are Ideal
Those who require cabling for intricate purposes such as circuit boards or electronic devices will favor stranded wires as they’ll remain intact and protected even if twisted or bent when connecting electrical components.
Situations Where Solid Cables are Ideal
Those who work outdoors or use heavy duty applications might expose the cables to corrosive particles, erratic movements and harsh weather conditions. Solid cables are best for these types of situations.
The Benefits of Solid Cables
Solid cables are often favored because they usually more affordable than the stranded variety due to their cheaper production costs. These cables are simple yet quite durable. As single, thick strands of cable, they are quite resistant to threats and very easy to produce. Solid cables also have a much more compact diameter compared to stranded cables. Yet this reduced size does not reduce the current carrying ability of solid cables. Add in the fact that solid cables are not as prone to failure as a result of corrosion and it is easy to see why they are held in high regard.
The Disadvantages of Solid Cables
Though solid cables have plenty of laudable characteristics, they also have a few flaws. One of the main problems with solid cables is that they are usually only sold in small gauges. Also, if there is constant flexing or vibrations, the cable could eventually wear down and break, creating the need for a replacement. Therefore, solid cables are not optimal for applications like robotics or vehicles that require a considerable amount of movement. If the cable must be bent into awkward shapes, the solid cable won’t have the appropriate amount of malleability and fortitude to remain fully intact.
Benefits of Stranded Cables
Stranded cables are easier to route in comparison to solid cables. They are also extremely flexible. Stranded cables can withstand an incredible amount of vibrations and flexing without fatiguing and eventually breaking. As a result, you won’t have to replace your stranded cables as often as will be necessary with solid cables.
Disadvantages of Stranded Cables
Stranded cables are far from perfect. Their diameter is quite large yet they provide a similar carrying capacity as solid cables. They are also more expensive as their production costs are considerably higher than solid cables. These costs are higher due to the complex manufacturing process that is required to develop these intricate wires. Also, stranded cables are much more likely to falter as a result of corrosion from capillary action. It is also worth noting that stranded cables are not ideal for preventing electronic interference as the air channels in between each strand amplify the “skin effect” created by the magnetic fields along the cable’s surface.
Be sure to take each of the factors listed above into account before making a commitment to either solid vs stranded cable for your home or business project.

Five Tips for Choosing QSFP28 Fiber Optic Transceivers

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The QSFP28 standard is designed to carry 100 Gigabit Ethernet, EDR InfiniBand. or 32G Fibre Channel. This transceiver type is also used with direct-attach breakout cables to adapt a single 100GbE port to four independent 25 gigabit ethernet ports (QSFP28-to-4x-SFP28). Sometimes this transceiver type is also referred to as “QSFP100” or “100G QSFP” for sake of simplicity. Please refer to the following tips for choose the right 100G Optical Modules for your modern data center.
Optical Modules Selection Based on Distance
<100 meter, When the transmission distance is within 100m, The QSFP28 SR4 optical module is highly recommended. The QSFP28 SR4 supports links up to 70m via OM3 Multimode fiber and 100m via OM4 Multimode fiber, with MPO / MTP fiber interface. It offers 4 independent transmitting and receiving channels, and each is with 25Gbps able to be aggregated into 100Gbps. Meanwhile, the QSFP28 SR4 optic module is also ideal for the connections from rack to rack in the data center.
100m to 10km, When the transmission distance is over 100m but shorter than 10 km, the QSFP28 LR4 optical transceiver is preferred. The QSFP28 LR4 is a fully integrated 4 × 25Gbit/s optical transceiver module, supporting distance up to 10 km. So for long span 100G deployment, such as cabling between two buildings, QSFP28 LR4 with duplex LC and single-mode fiber cable is the perfect option.
>10km, When transmission distance exceeds 10 km, the QSFP28 ER4 module is ideal for very long transmission distance. It provides superior performance for 100G Ethernet applications up to 30km links and converts 4 input channels of 25Gb/s electrical data to 4 channels of LAN WDM optical signals and then multiplexes them into a single channel for 100Gb/s optical transmission.
Optical Modules Selection Based on Applications
QSFP28 CWDM4 provides a 100G Ethernet high-speed link with a maximum transmission distance of 2 km, which interfaces with LC duplex connectors, and uses Mux/Demux technologies with 4 lanes of 25Gbps optically multiplexed into and demultiplexed from duplex single-mode fiber.
QSFP28 PSM4 doesnot need any MUX/DEMUX technology for each laser but it does need either a directly modulated DFB laser (DML) or an external modulator for each fiber. Besides, with an MPO/MTP interface, PSM4 modules can transmit data at 100Gb/s from point to point over 2 km or can be divided into dual 50Gb/s or quad 25Gb/s links for linking to servers, storage and other subsystems.
It’s seen from that both of QSFP28 CWDM4 and QSFP28 PSM4 are designed to meet the requirement for intermediate or mid-reaches for datacenter applications (500 m to 2 km). And they both use WDM and parallel single mode fiber technologies and support transmission distance up to 2 km.
When faced with such a situation, maybe we can make a decision from the two aspects. For one thing, from the aspect of an inner transceiver module structure, by comparison , PSM4 can be more cost-effective due to its lower component costs. For another thing, from the infrastructure viewpoint, PSM4 will be more expensive when the link distance is long, because PSM4 uses 8 optical single-mode fibers while CWDM uses only 2 optical single-mode fibers.

QSFP28 Transceiver Modules Installation Guide

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CAUTION:
When installing or removing a transceiver module, avoid touching the golden plating on the transceiver module with a bare hand.
Do not remove the dust plug from a transceiver module if you are not to connect an optical fiber to it.
Remove the optical fibers, if any, from the transceiver module before installing it.
To avoid ESD damage, wear an ESD wrist strap when installing or removing an QSFP28 transceiver module or network cable. Make sure the wrist strap makes good skin contact and attach the wrist strap wire to the ESD jack (if any) on the device chassis as shown in the left part of Figure 1, or to the rack with an alligator clip as shown in the right part of Figure 1.
Installing and removing a QSFP28 transceiver module
QSFP28 transceiver module can have either a plastic bail-clasp latch or a metallic bail-clasp latch. The following uses the QSFP28 transceiver module with a metallic bail-clasp latch as an example.
Installing a transceiver module
Remove the optical fiber, if any, from the module.
Pivot the bail-clasp latch of the module up, as shown by callout 1 in Figure 1. (Skip this step if the bail-clasp latch is plastic.)
Align the module correctly with the port in the chassis. Gently push in the module until it is firmly seated in the port, as shown by callout 2 in Figure 1.
In case of limited space, you can gently push against the front face of the transceiver module instead of holding the sides.
If you are not to connect an optical fiber to the transceiver module, attach the dust plug to the module port.
Removing a transceiver module
Remove the optical fiber, if any, from the module.
Pivot the bail-clasp latch of the module down to the horizontal position. (Skip this step if the bail-clasp latch is plastic.)
Gently pull the module out of the port.

Overview of 100G QSFP28 Optical Transceivers

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QSFP28 fiber optic module has become the dominant form factor for 100G high-speed networks. The interconnect offers multiple channels of high-speed differential signals with data rates ranging from 25Gbps up to potentially 40Gbps, and meets 100Gbps Ethernet (4×25Gbps) and 100Gbps 4X InfiniBand Enhanced Data Rate (EDR) requirements. TARLUZ 100G QSFP28 optical transceiver including SR4, LR4, PSM4, CWDM4 and AOCs, complied with IEEE 802.3bm and SFF-8636, compatible with network device from different vendors, designed for applications of 100G Data Center Internal Network, Data Center Interconnection and Metro Network.
The following list is QSFP28 fiber optic transceivers form TARLUZ, it is able to compatible with the main network device provider like Cisco, HPE, Huawei, etc.
QSFP28 SR4: The QSFP28-SR4 optical module supports links of 70m over OM3 MMF and 100m over OM4 MMF with MPO-12 or MTP-12 connectors. This transceiver is a parallel 100G QSFP28 optical module with 4 independent transmit and receive channels each capable of 25Gb/s operation. The 100G QSFP28-SR4 modules are ideal for rack to rack connections in the datacenter and short reach telecom applications.The QSFP28-100G-eSR4 is extended version of QSFP for transmit over 300m.
QSFP28 PSM4: The 100G PSM4 specification defines requirements for a point-to-point 100 Gbps link over eight single mode fibers (4 transmit and 4 receive) of at least 500m, each transmitting at 25Gbps. Four identical and independent lanes are used for each signal direction. PSM4 does not need a MUX/DEMUX for each laser but it does need either a directly modulated DFB laser (DML) or an external modulator for each fiber. With an MTP interface, PSM4 modules can bus 100Gbps point-to-point over 2km or can be broken out into dual 50Gbps or quad 25Gbps links for linking to servers, storage and other subsystems.
QSFP28 CWDM4: The CWDM4 module uses Mux/Demux technologies with 4 lanes of 25 Gbps optically multiplexed onto and demultiplexed from duplex single-mode fiber. It is centered around the 1310nm band with 20nm channel spacing as defined by the ITU standard. With a reach of 2km, QSFP28 CWDM4 transmits 100G optical signals via a duplex LC interface.
QSFP28 LR4: This module is for longer span 100GbE deployment, such as connectivity between two buildings, QSFP28-LR4 with duplex LC fiber interface and transmitted over single-mode fiber cable. This LR4 module uses WDM technologies to achieve 100G transmission over four different wavelengths around 1310nm. It can support distances up to 10km.
QSFP28 ER4 Lite: QSFP28-ER4 Lite is a 100Gbps transceiver designed for optical communication applications compliant to Ethernet 100GBASE-ER4 Lite standard. The high performance cooled LAN WDM EA-DFB transmitters and high sensitivity APD receivers provide superior performance for 100Gigabit Ethernet applications up to 25km links without FEC and 32km links with FEC.

What are polarization maintaining fibers?

In the most common an optical fiber in which the polarization of linearly polarized light waves launched into the fiber is maintained during propagation, with little or no cross-coupling of optical power between the polarization modes.

 

In the most common an optical fiber in which the polarization of linearly polarized light waves launched into the fiber is maintained during propagation, with little or no cross-coupling of optical power between the polarization modes. Such fiber is used in special applications where preserving polarization is essential.

 

 What is polarization maintaining(PM) fibers ? 

 

Polarization Maintaining (PM) optical fiber is a key component of Fiber Optic Gyroscopes, devices that measure rotation in missiles, aircraft, ships and satellites. They are a type of interferometric sensor in which the phase difference between two light paths is measured.The polarization of light propagating in the fiber gradually changes in an uncontrolled (and wavelength-dependent) way, which also depends on any bending of the fiber and on its temperature. Specialised fibers are required to achieve optical performances, which are affected by the polarization of the light travelling through the fiber.optical fibers always exhibit some degree of birefringence, even if they have a circularly symmetric design, because in practice there is always some amount of mechanical stress or other effect which breaks the symmetry. As a consequence, the polarization of light propagating in the fiber gradually changes in an uncontrolled (and wavelength-dependent) way, which also depends on any bending of the fiber and on its temperature.

 

 Principle of polarization maintaining(PM) fibers

 

The mentioned problem can be fixed by using a polarization-maintaining fiber, which is not a fiber without birefringence, but on the contrary a specialty fiber with a strong built-in birefringence (high-birefringence fiber or HIBI fiber, PM fiber). In general, optical fiber telecommunications applications, PM fiber is used to guide light in a linearly polarised state from one place to another. To achieve this result, several conditions must be met. Input light must be highly polarised to avoid launching both slow and fast axis modes, a condition in which the output polarization state is unpredictable.

 

Provided that the polarization of light launched into the fiber is aligned with one of the birefringent axes, this polarization state will be preserved even if the fiber is bent. The physical principle behind this can be understood in terms of coherent mode coupling. The propagation constants of the two polarization modes are different due to the strong birefringence, so that the relative phase of such copropagating modes rapidly drifts away. Therefore, any disturbance along the fiber can effectively couple both modes only if it has a significant spatial Fourier component with a wavenumber which matches the difference of the propagation constants of the two polarization modes. If this difference is large enough, the usual disturbances in the fiber are too slowly varying to do effective mode coupling.In addition, connectors must have been installed on the PM fibers in such a way that internal stresses do not cause the electric field to be projected onto the unintended axis of the fiber.

 

Applications

 

PM optical fibers are used in special applications, such as in fiber optic sensing, interferometry and quantum key distribution. They are also commonly used in telecommunications for the connection between a source laser and a modulator, since the modulator requires polarized light as input. They are rarely used for long-distance transmission, because PM fiber is expensive and has higher attenuation than singlemode fiber.Optical fibers may be applied in measurements of electrical current, particularly as so-called optical current transformers. Electric current sensors, in which optical fibers are used are small, light, cheap and safe. Their sensitivity is, however, due to the restricted magnetootpic properties of optical fibers, rather small. Moreover, these sensors are susceptible to deformations of the optical fiber. An increase of their sensitivity consists in lengthening the distance of optical fiber on which the magnetic field acts.PM fibers are applied in devices where the polarization state cannot be allowed to drift, e.g. as a result of temperature changes. Examples are fiber interferometers and certain fiber lasers. A disadvantage of using such fibers is that usually an exact alignment of the polarization direction is required, which makes production more cumbersome. Also, propagation losses are higher than for standard fiber, and not all kinds of fibers are easily obtained in polarization-preserving form.

 

Fiber-MART offer polarization components can be utilized in high power optical amplifiers and optical transmission system, test and measurement. the launch conditions at the optical fiber end face must be consistent with the direction of the transverse major axis of the fiber cross section. Fiber-Mart Polarizing Beam Combiner/Splitter (PBC/PBS) is a compact high performance light wave component that combines two orthogonal polarization signals into one output fiber, and also can split the incoming light into two orthogonal states. We also supply the Isolator type (IPBC/IPBS) which provides both polarization beam combining and optical isolation in one integrated component.for more information,you can visit www.fiber-mart.com.pls feel free to contact with us for any question . E-mail: service@fiber-mart.com

OM4 fiber optic cabling

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OM4 Specifications
How does OM4 compare to OM1, OM2, OM3, and single mode? There are significant differences between most of the standardized types of glass. A select few of the major attributes of these different glass types are shown below to highlight the differences.
It is important to note that OM4 glass is not necessarily designed to be a replacement for OM3. Despite the relatively long-standing availability of OM4, there are no plans to obsolete OM3 fiber optic cabling. For most systems, OM3 glass is sufficient to cover the bandwidth needs at the distances of the current installation base. Most system requirements can still be reliably and cost effectively achieved with OM3, and this glass type will remain available for the foreseeable future.
Despite the availability of OM4 glass, OM3 is quite capable of 40 and 100 Gb/s applications albeit at significantly shorter distances than OM4. The primary benefit that OM4 provides is additional reach at extended bandwidth at an overall cost still less than that of an OS2 singlemode system. In other words, OM4 provides a solution that allows more installations to avoid the significantly higher costs of singlemode systems.
OM4 Compatibility
Additionally, OM4 provides an opportunity to future-proof cabling infrastructure. OM4 is completely backwards-compatible with existing OM3 systems. As a result, these two grades of glass are interchangeable within the transmission distance limitations outlined above. The additional bandwidth and lower attenuation of OM4 provide additional insertion loss margin. As a result, users of OM4 gain additional safety margin to help compensate for less-than-ideal cabling installations as well as provide margin for degradation due to moves, adds, and changes over the life of the installation.
As increased bandwidth requirements are called out in new installations, particularly 40 and 100 Gb/s standards, transmission distances over fiber optic cables contained in existing infrastruOM4-LC-LC-Patch-Cord-1cture may become increasingly limited. Increasingly, these higher bandwidth system requirements have dictated a need to transition from cost-effective multi-mode systems to more costly single-mode systems. Until OM4 was formally specified, many next-generation 40 and 100 Gb/s applications would have had to make the leap to single-mode system solutions. OM4 effectively provides an additional layer of performance that supports these applications at longer distances, thereby limiting the number of installations that truly require OS2 singlemode fiber. OM4 can provide a minimum reach of 125m over multimode fiber within the 40 and 100 GbE standards.