Fiber coupling type

What are the classifications of fiber optic couplers? What is a fiber optic coupler, and what are the principles and uses of a fiber optic coupler? Fiber optic couplers are also called fiber optic adapters, also known as fiber optic flanges.

Definition: A device for detachable (movable) connection between an optical fiber and an optical fiber. It precisely butts the two end faces of the optical fiber so that the optical energy output by the emitting fiber can be coupled to the receiving optical fiber to the maximum extent, and the It intervenes in the optical link so that the impact on the system is minimized.

Classification: According to different classifications of optical fibers

SC fiber coupler: applied to SC fiber interface, if it is 8 thin copper contacts, it is RJ-45 interface, if it is a copper column, it is SC fiber interface.

LC fiber optic coupler: used in LC fiber optic interface, the connector connected to the SFP module, commonly used in routers.

FC fiber coupler: applied to FC fiber interface, generally used on the ODF side.

ST fiber coupler: applied to ST fiber interface, often used in fiber distribution frame.

What is the principle and use of fiber coupler

Optical network systems also need to couple, branch, and distribute optical signals, which requires fiber couplers to achieve. Optical fiber coupler, also known as optical splitter and optical splitter, is one of the most important passive devices in optical fiber links. It is a fiber optic junction device with multiple input ports and multiple output ports. M×N is often used to represent a A splitter has M inputs and N outputs.

Optical splitters used in fiber optic CATV systems are generally 1×2, 1×3 and 1×N optical splitters composed of them

principle

It can be divided into two types: fused tapered type and planar waveguide type. The fused tapered type product is made by welding two or more optical fibers on the side; the planar waveguide type is a micro-optical element type product. Or form an optical waveguide on a semiconductor substrate to realize the branch distribution function.

The two types of light splitting principles are similar. They achieve different sizes of branches by changing the evanescent field mutual coupling (coupling degree, coupling length) between fibers and changing the fiber radius. Conversely, multiple optical signals can be combined into one signal. called a synthesizer. Fused taper fiber coupler has become the mainstream manufacturing technology in the market because of its simple manufacturing method, low price, easy connection with external optical fiber, and the advantages of being resistant to mechanical vibration and temperature changes.

The fusion tapering method is to scramble two (or more than two) optical fibers with the coating removed in a certain way, melt them under high temperature heating, and stretch them to both sides at the same time, and finally form a double cone in the heating zone. With the special waveguide structure, different light splitting ratios can be obtained by controlling the twisted angle and stretched length of the fiber.

Finally, the tapered area is solidified on the quartz substrate with curing glue and inserted into the stainless copper tube, which is the optical splitter. Due to the inconsistency of the thermal expansion coefficient of the cured glue with that of the quartz substrate and the stainless steel tube in this production process, the degree of thermal expansion and contraction is inconsistent when the ambient temperature changes. This situation is likely to cause damage to the optical splitter, especially the optical splitter. The situation in the wild is even worse, which is also the main reason why optical splitters are easily damaged. For the production of more splitters, multiple splitters can be used.