FIBER LASERS

F R A U N H O F E R I N S T I T U T E F O R L A S E R T E C H N O L O G Y I LT

DQS certified by

DIN EN ISO 9001

Reg.-No.: DE-69572-01

Fraunhofer-Institut

für Lasertechnik ILT

Steinbachstraße 15

52074 Aachen, Germany

Telephone +49 241 8906-0

Fax +49 241 8906-121

info@ilt.fraunhofer.de

www.ilt.fraunhofer.de

Fraunhofer Institute for Laser Technology ILT

The Fraunhofer Institute for Laser Technology ILT is worldwide

one of the most important development and contract research

institutes of its specific field. The activities cover a wide range

of areas such as the development of new laser beam sources

and components, precise laser based metrology, testing

technology and industrial laser processes. This includes laser

cutting, caving, drilling, welding and soldering as well as

surface treatment, micro processing and rapid manufacturing.

Furthermore, the Fraunhofer ILT is engaged in laser plant

technology, process control, modeling as well as in the

entire system technology. We offer feasibility studies,

process qualification and laser integration in customer

specific manufacturing lines. The Fraunhofer ILT is part

of the Fraunhofer-Gesellschaft.

Subject to alterations in specifications and other technical information. 06/2019.

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

Contact

Dipl.-Phys. Oliver Fitzau

Telephone +49 241 8906-442

oliver.fitzau@ilt.fraunhofer.de

Dipl.-Ing. Hans-Dieter Hoffmann

Telephone +49 241 8906-206

hansdieter.hoffmann@ilt.fraunhofer.de

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.

Title: Q-switched high-power fiber laser.

1 Adapter for vibration tests on fiber components.

2 Highly stable fiber laser for gravitational measurements.

3 Active fiber in laser base plate.

4 Soldered Pockels cell as a Q-switch.

5 Narrow-band fiber laser for the investigation

of stimulated Brillouin scattering (SBS).

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