Fiber Lasers

Brochure Fiber Lasers
Brochure Fiber Lasers

The Fraunhofer Institute for Laser Technology ILT develops adapted, fiber-based beam sources for pulsed  or continuous wave operation and offers extensive know-how in the fields of highly stable fiber lasers,  high-power fiber lasers, simulation, assembly and joining technology as well as laser components. The  institute mainly focuses on solutions for industrial applications.

Fiber lasers combine highest beam quality and efficiency in both continuous and pulsed operation. Since such lasers can be designed monolithically and, therefore, very robustly without free-space components, they have established them-selves in industrial applications alongside gas and solid-state lasers and have already partially replaced them. As their output parameters such as power, wavelength or pulse shape are so flexible, fiber lasers can be used for a wide range of applications. In material processing, they can be used, for example, for ablation and welding; in metrology, for interferometry and also in medical technology applications.

High-power fiber lasers for industrial applications

In various R&D projects, Fraunhofer ILT scientists are creating lasers with output powers in the kW range. Using fiber Bragg gratings and pump light couplers, they can develop fully fiber-integrated and thus particularly robust fiber lasers as resonators or amplifiers. The output signal can be unpolarized or linearly polarized, depending on the requirements. 

In cooperation with our customers, we design and  conceptualize customized beam sources for a wide variety of applications:

  • Linearly polarized single-mode fiber lasers with output powers over 1 kW
  • Single-mode fiber lasers with pulse durations in the pico to microsecond range and peak power of 100 kW
  • Q-switched, short-pulsed multimode fiber lasers with peak powers above 250 kW

Such lasers can be applied, for example, in the industrial structuring of surfaces with pulsed radiation, the preparation of adhesive surfaces of composite components or cutting and welding.

Highly stable fiber amplifiers for narrow band signals

Together with the European Space Agency ESA, Fraunhofer ILT is developing narrow-band and power-stable single-mode fiber amplifiers for future use in space applications, such as linearly polarized fiber amplifiers with an output power of up to 5 W and a line width below 10 kHz. The fiber amplifiers will be used to measure the static gravitational field or gravitational waves and in inter-satellite communication.

In order to investigate their suitability for space, Fraunhofer ILT will expose the lasers to various stresses such as shock, vibration, vacuum or cosmic radiation in a test campaign.

Simulation of optical components and fiber lasers

Various software tools are available at Fraunhofer ILT for the development and design of new beam sources. These tools are used to model both the thermo-mechanical properties using finite element methods (FEM) and the spectral and tem-poral properties of differently doped fiber lasers. In addition, modal properties can be simulated for propagation in any fiber geometry and mode coupling, e. g. in fiber Bragg gratings.

Fiber laser components, assembly and joining technology

The fiber laser design places the highest demands on the quality of the components. For this reason, Fraunhofer ILT qualifies fiber-integrated and fiber-coupled components in extensive tests for their respective applications. In many cases, commercial components are not available due to the special requirements and, therefore, have to be developed  

at Fraunhofer ILT.

Examples for adapted fiber laser components

  • Fiber Bragg gratings for multimode fibers
  • Isolators and Pockels cells for use in space and that are free of organic materials
  • Soldered Pockels cells for use in high-power fiber lasers
  • Isolators for use in high-power fiber lasers with powers up into the kW range
  • Pump and signal light couplers for adapted fiber geometries
  • Splice connections of special geometries for use in high-power fiber lasers