Introduction to optical fiber adapters for optical communica

Optical fiber adapter (Coupler), also known as Splitter (Splitter), connector, coupler, flange, is used to achieve optical signal shunt/junction, or used to extend the fiber link components, belongs to the field of optical passive components, in telecommunications networks, cable TV networks, user loop systems, regional networks will be applied to. Fiber couplers can be divided into standard couplers (waveguide, double branch, unit 1×2, which also divides the optical signal into two powers), direct coupling couplers (connecting two fibers of the same or different types of fiber interfaces to extend the fiber link), star/tree couplers, and wavelength multiplexers (WDM), if the wavelength is high-density separation, that is, the wavelength spacing is narrow. It belongs to DWDM), and the production method is sintering (Fuse), micro-optics (Micro Optics), and optical waveguide (Wave Guide), and the sintering method accounts for the majority of production (about 90%). The production method of sintering method is to melt and stretch two optical fibers together, so that the core polymerization together, to achieve the optical coupling effect, and the most important production equipment is the optical fiber welding machine, which is also an important step, although the important step part can be manufactured by the machine, but after sintering, it is still necessary to work to detect packaging, so the labor cost accounts for about 10 ~ 15%. Moreover, the use of manual detection package must ensure the consistency of quality, which is also a mass production must be overcome, but the technical difficulty is not as high as DWDM modules and optical active components, so the initial want to enter the optical fiber industry manufacturers, most will cut from the optical coupler, gross profit is 20 ~ 30%.

 

Performance index:

 

● Input loss: ≤0.3dB(PC)≤0.2dB(UPC)<0.2dB(APC) ≤0.3dB(multi-mode)

 

● Return loss: ≥40dB(PC)≥50dB(UPC)≥60dB(APC) ≥35dB(multi-mode)

 

● Interchangeability: ≤0.2dB Operating temperature (℃) : -30 - +80

 

● Storage temperature (℃) : -40 - +85

 

Vibration test: ≤0.1dB(10-60Hz,1.5mm amplitude)

 

● Tensile strength test: ≤0.1dB(0-15Hg tensile force, except φ0.9mm fiber)

 

● Repeatability: ≥1000 times

 

sort

 

According to the different coupling fibers are classified as follows:

 

SC fiber coupler: Applied to the SC fiber interface, it looks very similar to the RJ-45 interface, but the SC interface is more flat, and the obvious difference is the contact plate inside, if it is 8 thin copper contact plates, it is the RJ-45 interface, if it is a copper column, it is the SC fiber interface.

 

LC Fiber coupler: Applied to the LC fiber interface, the connector connecting the SFP module, it uses the easy to operate modular jack (RJ) latch mechanism. (Commonly used routers)

 

FC fiber coupler: Applied to the FC fiber interface, the external strengthening mode is metal sleeve, tightening mode is turnbuckle. Generally used on the ODF side (most used on the distribution frame)

 

ST optical fiber coupler: Applied to ST optical fiber interface, usually used in optical fiber distribution frame, shell is round, fastening method is turnbuckle. For 10Base-F connections, the connector is usually of type ST. Commonly used in optical fiber distribution frames)

 

principle

 

The optical fiber coupler is a detachable (movable) connection device between the optical fiber and the optical fiber, which is the precision docking of the two end faces of the optical fiber, so that the light energy output of the transmitting optical fiber can be coupled to the receiving optical fiber to the maximum extent, and its involvement in the optical link to minimize the impact on the system. For a waveguide fiber coupler, it is generally a component with a Y-branch, and the optical signal input by one fiber can be equally divided by it. When the open Angle of the coupler branch increases, the light leaking to the cladding will increase, increasing the excess loss, so the open Angle is generally within 30°, so the length of the waveguide fiber coupler can not be too short.