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Disputation: Lars Grønmark Holmen Lars Grønmark Holmen by the Department of Technology Systems will be defending his thesis: 

Development of 1.5 µm and 2 µm fiber lasers and applications in 3D-imaging and mid-infrared generation

for the degree of Philosophiae Doctor.

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The PhD defence will be fully digital and streamed directly using Zoom. The host of the session will moderate the technicalities while the chair of the defence will moderate the disputation.

Ex auditorio questions: the chair of the defence will invite the audience to ask ex auditorio questions either written or oral. This can be requested by clicking 'Participants -> Raise hand'.

Attend the disputation

Download Zoom

Request the thesis.

Trial lecture

Integrated optics - present and future (download)

Main research findings

Lasers find widespread use in a variety of fields such as industrial materials processing, laser surgery, telecommunications, metrology, and defense. Particularly fiber lasers have emerged over the last few decades as a notably attractive laser architecture for practical applications. In a fiber laser, light amplification occurs inside optical fibers that act as waveguides. These fibers can be spliced together to form monolithic and alignment-free laser systems that offer extreme reliability in demanding environments. Most scientific and commercial success has to date been achieved with ytterbium-doped fiber lasers that emit at wavelengths around 1.1 µm. There are however numerous laser applications that benefit from fiber laser emission at other less conventional wavelengths. This thesis presents development of silica fiber lasers doped with erbiumthulium and holmium ions, which emit at wavelengths around 1.5 µm and 2 µm. Pulsed lasers operating in the nanosecond regime with high pulse energy and peak powers are reported, along with a widely tunable holmium laser that emits at 2.025 – 2.2 µm. The sources developed are performance tailored to selected laser applications. Specifically, this work demonstrates lasers used for 3D-imaging at long ranges (several kilometers) and generation of mid-infrared emission (3-5 µm) through optical frequency conversion.

For more information

PhD advisor, Ida Elisabeth Rydning, 

Technician, Arild Hemstad,

Published June 15, 2021 9:36 AM - Last modified June 25, 2021 8:43 AM