Explore More about the Basics of Fiber Couplers

To the basic components of many fiber-optic setups, the fiber coupler belongs. Note that with two different meanings, the term fiber coupler is used:

With multiple outputs and input fibers, it can be an optical fiber device. Based on the polarization and wavelength at one or more outputs, Light from an input fiber can appear with the power distribution potentially. For coupling light from free space into a fiber, It can also be a device.

Coupling Loss

All fibers involved are single-mode in many cases and for a given wavelength; they support only a single mode per polarization direction. On the performance of the coupler, there are then certain physical restrictions. In particular, combining multiple inputs of the same optical frequency into a single-polarization output is not possible without significant excess losses. This can happen only if the optical phases of the input beams are stabilized and adjusted precisely. That means that the two inputs would have to be mutually coherent to be combined. You can buy fiber splitter online.

Bandwidth

Only in a limited range of wavelengths, do most types of couplers work as the coupling strength is dependent on wavelength. Of those couplers where the coupling occurs over a certain length, this is a typical property. A few tens of nanometers are typical bandwidths of fused couplers. They can be used as beam combiners or dichroic couplers as mentioned above.

Typical Applications

Some typical fiber couplers applications:

• In fiber interferometers, Fiber couplers can be used for example for optical coherence tomography (OCT). For such purposes, specially designed broadband couplers are often required.
• The powerful signal from one transmitter is sent into a fiber-optic splitter in a cable TV system. For different customers, it distributes the power over a large number of output fibers.
• For sending them into the inner cladding of the active fiber and combining the radiation of several laser diodes, multimode fiber couplers are often used in high-power fiber amplifiers and lasers.
  

Another fiber coupler can be used as the output coupler and a dichroic fiber coupler can be used to inject pump light within the resonator of a fiber laser. Having no resonator ends where light could be injected, this technique is used particularly in fiber ring lasers.