Multiple pump sources can be combined into a single output using Nx1 pump combiners, which are crucial parts of fiber optic systems. They are frequently employed in amplifiers, high-power fiber lasers, and other applications that call for high optical power. In this blog, we will examine the fundamentals of Nx1 pump combiners in this article, including their operation, applications, and many varieties.

What is an Nx1 pump combiner?

An optical coupler known as an Nx1 pump combiner combines N pump sources into a single output fiber. While there are N input fibers, there is only 1 output fiber, denoted by the number 1. In order to combine numerous pump sources, each operating at a distinct wavelength, into a single output fiber, these combiners are generally utilized in fiber laser and amplifier systems. They can considerably boost the system’s output power by doing this.

How do Nx1 pump combiners work?

Nx1 pump combiners operate on the fundamental principle of wavelength division multiplexing (WDM). This method combines several light wavelengths into a single optical fiber. In order for WDM to function, the various light wavelengths must first be separated using optical filters before being recombined into a single output fiber.

The pump sources are connected to the input fibers of an Nx1 pump combiner, which then uses WDM filters to combine them into a single output fiber. The combined optical power can be efficiently coupled since the output fiber normally has a bigger diameter than the input fibers.

Nx1 pump combiners’ various types

Nx1 pump combiners come in a variety of designs, each with its unique benefits.

Combiners for Fused-taper Nx1 pumps

Tapering numerous fibers together results in the creation of fused-taper Nx1 pump combiners. Low insertion loss and excellent coupling efficiency are produced as a result of the output fiber’s seamless transition from the input fibers. These combiners may be delicate to temperature fluctuations and difficult to build.

Combiners for fused-bundle Nx1 pumps

A bundle of fibers is fused together to create a fusion-bundle Nx1 pump combiner. In comparison to fused-taper combiners, this results in a robust structure that is less sensitive to temperature variations. However, the lack of a smooth transition between the input fibers and the output fiber may result in a decreased coupling efficiency.

PNX1 pump combiners on a plane

Planar waveguide technology is used to create planar Nx1 pump combiners. They are composed of a substrate-borne thin-film waveguide layer. Following that, the input fibers are connected to the waveguide layer, enabling effective optical power coupling. Although they can be mass-produced and are incredibly tiny, planar combiners may have significant insertion loss.

The use of Nx1 pump combiners

Nx1 pump combiners are employed in numerous applications, such as:

High-power fiber lasers

High-power fiber lasers frequently employ Nx1 pump combiners to combine various pump sources into a single output fiber. More output power and greater beam quality are attainable as a result of a single pump source.

Laser amplifiers

Devices called optical amplifiers use a pump source to amplify optical signals. Higher output power and greater performance are made possible by the employment of Nx1 pump combiners, which combine numerous pump sources into a single output fiber.

Conclusion

In order to combine several pump sources into a single output fiber, Nx1 pump combiners are crucial parts of fiber optic systems. They are frequently employed in amplifiers, high-power fiber lasers, and other applications that call for high optical power. Nx1 pump combiners come in a number of distinct varieties, each with unique benefits and drawbacks. Anyone working in the fiber optics industry should be familiar with the fundamentals of Nx1 pump combiners because they are crucial parts of many different systems.