A fiber-optic splitter, also known as a

beam splitter A beam splitter or beamsplitter is an optical instrument, optical device that splits a beam of light into a transmitted and a reflected beam. It is a crucial part of many optical experimental and measurement systems, such as Interferometry, int ...

, is based on a

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (aquatic environment), the earthy material that exi ...

of an integrated waveguide

optical Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultravio ...

power distribution device, similar to a coaxial cable transmission system. The optical network system uses an optical signal coupled to the branch distribution. The

fiber optic An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers find wide usage in fiber-optic communications, where they permit transmission over longer distances and at ...

splitter is one of the most important passive devices in the

optical fiber An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers find wide usage in fiber-optic communications, where they permit transmission over longer distances and at ...

link. It is an optical fiber tandem device with many input and output terminals, especially applicable to a passive optical network ( EPON,

GPON ITU-T G.984 is the series of standards for implementing a gigabit-capable passive optical network (GPON). It is commonly used to implement the link to the customer (the ''last kilometre'', or ''last mile'') of fibre-to-the-premises ( FTTP) serv ...

, BPON,

FTTX Fiber to the ''x'' (FTTX; also spelled "fibre") or fiber in the loop is a generic term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile telecommunications. As fiber optic ...

FTTH Fiber to the ''x'' (FTTX; also spelled "fibre") or fiber in the loop is a generic term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile telecommunications. As fiber opt ...

etc.) to connect the

main distribution frame In telephony, a main distribution frame (MDF or main frame) is a signal distribution frame for connecting equipment (inside plant) to cables and subscriber carrier equipment ( outside plant). Overview The MDF is a termination point within the ...

and the terminal equipment and to branch the optical signal.

Types

According to the principle, fiber optic splitters can be divided into Fused Biconical Taper (FBT) splitter and Planar Lightwave Circuit (PLC) splitters. The FBT splitter is one of the most common. FBT splitters are widely accepted and used in passive networks, especially for instances where the split configuration is smaller (1×2, 1×4, 2×2, etc.). The PLC is a more recent technology. PLC splitters offer a better solution for larger applications. Waveguides are fabricated using

lithography Lithography () is a planographic method of printing originally based on the miscibility, immiscibility of oil and water. The printing is from a stone (lithographic limestone) or a metal plate with a smooth surface. It was invented in 1796 by ...

onto a silica glass substrate, which allows for routing specific percentages of light. As a result, PLC splitters offer accurate and even splits with minimal loss in an efficient package.

Balanced splitters

Balanced (2xN) splitters consists of 2 input fibers and N output fibers which divide the power of the optical signal proportionally. They are mainly used for non-simultaneous redundancy.

Splitting ratio principle

Wave splitting involves dividing a light beam into multiple streams. The daughter streams can be equal or in some other ratio. The FBT splitter uses two (or more) fibers. The fibers' coating layer is removed. Both fibers, at the same time, are stretched under a heating zone thus forming a double cone. This special waveguide structure allows control of the splitting ratio via controlling length of the fiber torsion angle and stretch. The PLC splitter is a micro-optical element using

photolithographic Photolithography (also known as optical lithography) is a process used in the manufacturing of integrated circuits. It involves using light to transfer a pattern onto a substrate, typically a silicon wafer. The process begins with a photosensit ...

techniques to form optical waveguide at medium or

semiconductor A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...

substrate for realizing branch distribution function. For example, graded-index silica-glass waveguides could be used to fabricate PLC optical splitters, and the splitting ratio can be simply adjusted during the design and fabrication phases.{{cite journal , last1=Awad , first1=Ehab , title=V-splitter with adjustable power splitting ratio , journal=Optical and Quantum Electronics , date=September 2017 , volume=49 , issue=9 , page=300 , doi=10.1007/s11082-017-1137-x , s2cid=254898153

Advantages and disadvantages

* The FBT splitter offers low cost, common materials (quartz substrate, stainless steel, fiber, hot dorm, GEL), and an adjustable splitting ratio. However, its losses are wavelength-dependent and it offers poor spectral uniformity, cannot ensure uniform spectroscopy, and is temperature sensitive. * PLC splitter: Losses are not sensitive to the wavelength, spectral uniformity is higher and it is more compact and has lower cost with greater degrees of splitting. However, device fabrication process is more complex.

References

Fiber-optic communications

Types

Balanced splitters

Splitting ratio principle

Advantages and disadvantages

See also

References