Fiber Optic Couplers,High Power Components,High Power Optical Isolators

Fiber optics are used for a variety of applications in the photonics industry. Fiber optics are typically connectorized for convenience of mating and coupling. These connectors come in many configurations and styles. A fiber optic connector that was lower loss, lower cost, easier to terminate or solved some other perceived problem is urgently needed to the industry. As a result, about 100 fiber optic connectors have been introduced to the marketplace, but only a few represent the majority of the market. Today, Fiberstore’s Blog are going to show you these commonly used fiber optic connectors.

Fiber Optic Connector Types
Commonly used fiber optic connector types include SC, FC, LC, ST, MU, E2000, MTRJ, SMA , DIN as well as MTP & MPO etc. They are widely used in the termination of fiber optic cables, such as fiber optic pigtail, fiber optic patch cables and so on.

	LC Connector (Lucent Connector) — Ferrule diameter = 1.25mm. LC connectors are licensed by Lucent and incorporate a push-and-latch design providing pull-proof stability in system rack mounts. LC connectors are available in single mode and multimode. Externally LC connectors resemble a standard RJ45 telephone jack. Internally they resemble a miniature version of the SC connector. This type of connectors are commonly used in connecting SFP Transceiver Module in Router/Switch. For example, the optic interfaces of Cisco’s SFP transceivers are all LC connectors.
	SC Connector (Subscriber Connector) — Ferrule diameter = 2.5mm. The SC connector is becoming increasingly popular in single-mode fiber optic telecom and analog CATV, field deployed links. But the most commonly used field is to connect GBIC (100Base-FX) in router/switch. The high-precision, ceramic ferrule construction is optimal for aligning single-mode optical fibers. The connectors’ outer square profile combined with its push-pull coupling mechanism, allow for greater connector packaging density in instruments and patch panels. The keyed outer body prevents rotational sensitivity and fiber endface damage. Multimode versions of this connector are also available. The typical insertion loss of the SC connector is around 0.3 dB.
	ST Connector (Straight Tip) — Ferrule diameter = 2.5mm. ST connector’s high-precision, ceramic ferrule allows its use with both multimode and single-mode fibers. The bayonet style, keyed coupling mechanism featuring push and turn locking of the connector, prevents over tightening and damaging of the fiber end. The insertion loss of the ST connector is less than 0.5 dB, with typical values of 0.3 dB being routinely achieved. ST connector is used extensively both in the field and in indoor fiber optic LAN applications, eg. ODF (optical distribution frame). In addition, ST connector is also used to connect GBIC transceiver, usually for 100Base-F.
	FC Connector (Ferrule Connector) — Ferrule diameter = 2.5mm. The FC has become the connector of choice for single-mode fibers and is mainly used in fiber-optic instruments, SM fiber optic components, and in highspeed fiber optic communication links. This high-precision, ceramic ferrule connector is equipped with an anti-rotation key, reducing fiber endface damage and rotational alignment sensitivity of the fiber. The key is also used for repeatable alignment of fibers in the optimal, minimal-loss position. Multimode versions of this connector are also available. The typical insertion loss of the FC connector is around 0.3 dB.
	MU Connector (Miniature Unit) — Ferrule diameter = 1.25mm. MU is a small form factor SC. It has the same push/pull style, but can fit 2 channels in the same Footprint of a single SC. MU was developed by NTT. It is a popular connector type in Japan. Applications include high-speed data communications, voice networks, telecommunications, and dense wavelength division multiplexing (DWDM). MU connectors are also used in multiple optical connections and as a self-retentive mechanism in backplane applications.
	MTRJ Connector (Mechanical Transfer Registered Jack) — Ferrule diameter = 2.45×4.4 mm. MT-RJ is a duplex connector with both fibers in a single polymer ferrule. It uses pins for alignment and has male and female versions. Multimode only, field terminated only by prepolished/splice method.
	E2000 Connector — Ferrule diameter = 2.5mm. E2000 connector is a plastic push-pull connector developed by Diamond. The E2000 was developed as an improvement on the SC connector design by having: a latch that retains the connector, a dust cap always in place, and a smaller size. The built in dust cap always stays on the connector protecting the ferrule and blocking harmful laser light when the connector is disconnected. E2000 is available for Singlemode and Multimode applications.
	SMA Connector (Sub Miniature A) — Ferrule diameter = 3.14mm. Due to its stainless steel structure and lowprecision threaded fiber locking mechanism, this connector is used mainly in applications requiring the coupling of high-power laser beams into large-core multimode fibers. Typical applications include laser beam delivery systems in medical, bio-medical, and industrial applications. The typical insertion loss of an SMA connector is greater than 1 dB.
	DIN Connector — Ferrule diameter = 2.5mm. DIN connector is a metal screw on connector which is developed by Siemens. Deutsch Telecom mainly uses it. This is a good connector to use where the ruggedness of a metal screw on connector is required but where there is not enough space for a FC Connector.
	MTP and MPO Connector — MTP and MPO are compatible ribbon fiber connectors based on MT ferrule which allow quick and reliable connections for up to 12 fibers. They are intended for installations that require many fiber connections. Up to 12 fibers in a ribbon are stripped to 125um cladding and inserted into 250um spaced parallel grooves. The ferrule also includes two 0.7mm diameter holes, running parallel to the fibers on the outer side of the ferrule. These two holes hold precision metal guide pins which align the fibers with tight tolerances. MTP and MPO connectors feature male and female connector design. Male connectors have two guide pins and female connectors do not. Both connector types need an adapter to mate a pair of male and female connectors. Because MTP and MPO connectors are trying to align so many fibers at once, their coupling loss are typically bigger than single fiber connectors.

History of Different Connector Types
The ST connector is the oldest design of the connectors still in common use. It was the first connector to use a 2.5mm ferrule. The FC and DIN connectors improved on the ST connector by: isolating cable tension from the ferrule, keying the location of the ferrule for angle polishing, and threading onto the adapter for a more positive connection. The SC connector was then developed to eliminate having to screw and unscrew the connector every time and to reduce the cost by molding instead of machining the connector. A big advantage of this push/pull connector over a FC connector is that less room is required between connectors on patch panels. The E-2000 was developed as an improvement on the SC connector design by having: a latch that retains the connector, a dust cap always in place, and a smaller size. As patch panel densities increased the LC and MU connectors were developed to reduce the space required for connectors on patch panels. Both of these connectors use a 1.25mm ferrule. The MT-RJ connector was then developed to put transmit and receive fibers into one connector. This was the first connector to use the MT ferrule design as opposed to a 2.5mm or 1.25mm diameter ferrule. The MTP connector was then developed to increase fiber density even more. The MTP currently has 12 fibers in its MT ferrule however a 24-fiber version is under development.

There are many more influences that lead to the development of these different commonly used connector types. This is why all of the different connector types exist. In fact, there are not only these connector types. A multitude of specialty connectors are launched to the market for different application.

Connector Endface Preparation
Once the optical fiber is terminated with a particular connector, the connector endface preparation will determine what the connector return loss, also known as back reflection, will be. The back reflection is the ratio between the light propagating through the connector in the forward direction and the light reflected back into the light source by the connector surface. Minimizing back reflection is of great importance in high-speed and analog fiber optic links, utilizing narrow line width sources such as DFB lasers, which are prone to mode hopping and fluctuations in their output.

Flat Polish — a flat polish of the connector surface will result in a back reflection of about -16 dB (4%).
PC Polish — the Physical Contact (PC) polish results in a slightly curved connector surface, forcing the fiber ends of mating connector pairs into physical contact with each other. This eliminates the fiber-to-air interface, there by resulting in back reflections of -30 to -40 dB. The PC polish is the most popular connector endface preparation, used in most applications.
UPC/SPC Polish — in the Super PC (SPC) and Ultra PC (UPC) polish, an extended polishing cycle enhances the surface quality of the connector, resulting in back reflections of -40 to -55 dB and < -55dB, respectively. These polish types are used in high-speed, digital fiber optic transmission systems.
APC Polish — the Angled PC (APC) polish, adds an 8 degree angle to the connector endface. Back reflections of <-60 dB can routinely be accomplished with this polish.

The main advantage of optical isolator Faraday effect of magneto-optic crystal. Faraday Faraday effect was first observed in 1845 does not have the optically active material in the magnetic field by rotating the polarization direction of the light occurs the substance, also known as magneto-optical effects. Polarized along the transmission direction of the magnetic field, the optical isolator is a polarization rotation angle θ and the magnetic field strength B and the material is proportional to the length L of the product. For normal incident signal light, after the passage to become a linearly polarized light from the polarizer, the Faraday rotating magnetic medium, together with the external magnetic field so that the right-handed polarization direction of the signal light 45, and just make a low loss through a polariser 45 placement of the analyzer. For the reverse light of the analyzer when a linearly polarized light through the medium is placed, the deflection direction is right-rotated by 45 degrees so that the polarization direction of the light and the backward direction perpendicular to the polarizer, the reflected light is completely blocked transmission .

Optical isolator variety, including on-line optical isolator, free-space optical isolators, etc. We provide a variety of optical isolators, used to meet the needs of different applications. 1310/1480 / 1550nm polarization-independent optical isolator interior design of two single-mode fiber for craft orthogonal polarization states were treated to ensure the entire device is independent of the polarization characteristics. Unipolar devices with low insertion loss, two-stage device has a high optical isolation, suitable for different applications, mainly used in optical fiber amplifiers, fiber lasers, fiber CATV networks, and satellite communications.

Faraday magnetic media within 1μm ~ 2μm wavelength range usually low optical loss yttrium iron garnet (YIG) single crystal. Novel pigtail input and output optical isolators have a fairly good performance, the minimum insertion loss of about 0.5dB, isolation of 35 ~ 60dB, up to 70dB. Usually the wavelength of the optical isolator to distinguish, 800-1300nm more, there are some specific wavelength.

An optical isolator is a passive optical components allows only unidirectional light through its working principle is based on Faraday rotation of non-reciprocity. Echo reflected light through the fiber can be well isolated optical isolators. The main advantage of optical isolator Faraday effect of magneto-optic crystal. Optical isolator features are: positive low insertion loss, high reverse isolation, high return loss. An optical isolator is blocked to allow the light to one direction and the opposite direction by the passive components, the role of limiting the direction of light, the light transmission in one direction only, the reflected return light passes through the optical fiber can be an optical isolator good isolation to improve the transmission efficiency of light.

OF-Link Communications Co., Ltd is a manufacturer and exporter specialized in fiber optic passive components. We focus on offering products with premium quality and competitive prices in the field of optical fiber communications, fiber laser and fiber sensor applications.

 Fiber Optic isolator allow only one-way light passes through, and its operating

principle is based on Faraday rotation of non-reciprocity. Echo reflected light through the fiber can be well isolated optical isolator. The main advantage of the optical isolator   magneto-optical Faraday effect transistor. Optical isolator features are: positive low insertion loss, high reverse isolation, high return loss. The optical isolator allows the light to one direction is prevented by the opposite direction by the passive components, the function is to limit the direction of the light, the light transmission in one direction only, the reflected return light passes through the fiber optical isolator can be good isolation and improve light transmission efficiency, optical isolator is characterized by high isolation, low insertion loss; high reliability, high stability; very low polarization dependent loss and polarization mode dispersion. Its role is to prevent the adverse effects of light and transmitted light generated by the optical system, e.g., between the semiconductor laser source and an optical transmission system is installed in the optical path due to various causes an optical isolator can largely reduce the adverse effects of reflected light on the stability of the light source spectral output power generated. In the high-speed direct modulation direct detection optical fiber communication systems, the transmission of the light will produce additional noise in the system performance degradation, which also requires an optical isolator to eliminate. Both ends of the fiber amplifier doped fiber isolator is mounted glazing can improve the stability of the optical fiber amplifier, without it, the reflected light enters the source (laser), causing severe fluctuation source. In coherent optical long-distance optical fiber communication systems, at some distance install an optical isolator can reduce the power loss caused by stimulated Brillouin scattering by. Thus, the optical isolator has an important role in optical fiber communication, optical information processing systems, and precision measuring optical fiber sensing system.

The main advantage of the Fiber optical isolator magneto-optical Faraday effect transistor. Faraday Faraday effect was first observed in 1845 is not optically active material in the magnetic field by rotating the polarization direction of light occurring substance, also known as magneto-optical effects. Polarized light transmitted along the magnetic field, whose direction of polarization rotation angle θ and the magnetic field strength B and the material is proportional to the length L of the product. Optical isolator works shown in Figure 1. For normal incident signal light, through a polarizer becomes the linearly polarized light, the Faraday rotating magnetic medium and the polarization direction of the external magnetic field with the right hand 45 of the signal light, and just make a low loss through the polarizer 45 placement of the analyzer. For the reverse light, a polarization analyzer after the placement of the media line deflection direction is right-rotated by 45 degrees, thereby reversing the direction of polarization of the light and the direction perpendicular to the polarizer, the reflected light is completely blocked transmission . Faraday magnetic media within 1μm ~ 2μm wavelength range usually low optical loss yttrium iron garnet (YIG) single crystal. New pigtail input and output optical isolator has a very good performance, the minimum insertion loss of about 0.5dB, isolation of 35 ~ 60dB, up to 70dB.

OF-Link Communications Co., Ltd. is a manufacturer and exporter specializing in optical passive components. We focus on providing high quality products with competitive quality and price of applications in optical fiber communication, fiber lasers and fiber-optic sensor. Main products have polarization maintaining (PM) fiber optic components, high power fiber laser components, high power fiber laser components, high power fiber laser components, high power fiber laser components, fused / filter fiber coupler, WDM, CWDM, DWDM, bandpass filter, fiber optical isolators and circulators, variable optical attenuator (VOA), fiber collimator, fiber distribution cables and so on. OF-LINK is located in Shenzhen, China, fiber optic components based on their business nine years of experience in; our production facilities have passed the ISO 9001:2008 certification, providing products comply with RoHS, IEC and Telcordia requirements. Our 100% visual and optical testing to ensure that all products meet international industry standards.

With optical manufacturing capabilities, testing services, global logistics and supply chain management, OF-LINK is ready to meet the special requirements of customers from around the world the full spectrum. Our customers are mainly manufacturers at the University of telecommunications, fiber lasers and fiber-optic sensors, and research institutes around the world. Due to the high demand for fiber optic networks and the development of a larger fiber optic products, in 2009, OF-LINK merged with Compass Technology Co., Ltd. is located in Jiangsu Nantong City Chongchuan Development Zone, Jiangsu Province. This is a high-tech company who is engaged in the application of Beidou satellite and fiber-optic communications; OF-LINK participate in its optical parts, and solely responsible for the overseas market. We completed the production of one million units in line timing device 900 million units, “fiber optic connectors and 100 million units,” the PLC splitter annual building. The project was included in the major scientific and technological achievements into special funds for the project, and has broad prospects for the industry. OF-LINK idea is first to meet customer needs: quality and reliability assurance, timely delivery and reliability, to protect customers’ intellectual property (IP), efficient supply chain management, comprehensive and timely customer response system that allows its better serve the majority of consumers. Our company offers fiber optic isolators, quality assurance, affordable, hope there is a demand can come to purchase.