Short Courses

SC290 High Power Fiber Lasers and Amplifiers

Sunday, February 24, 9:00 a.m. - 12:00 p.m.
Johan Nilsson; Univ. of Southampton, UK

Level: Advanced Beginner (basic understanding of topic is necessary to follow course material)

Course Description
This course describes the principles of high power fiber lasers and amplifiers, with output powers that can exceed a kilowatt. It describes the fundamentals of such devices and discusses current state of the art and research directions of this rapidly advancing field. Fiber technology, pump laser requirements and input coupling will be addressed. Rare-earth-doped fiber devices are the focus of the course, but Raman lasers and amplifiers will be considered, too, if time allows. This includes Yb-doped fibers at 1.0 - 1.1 μm, Er-doped fibers at 1.5 - 1.6 μm, and Tm-doped fibers at around 2 μm. Operating regimes extending from continuous-wave single-frequency to femtosecond pulsed will be considered. Key equations will be introduced to find limits and identify critical parameters. For example, pump brightness is a critical parameter for some devices in some regimes but not always. Important limitations relate to nonlinear and thermal effects, as well as damage, energy storage and, of course, materials. Methods to mitigate limitations in different operating regimes will be discussed. Fiber, laser and amplifiers designs for different operating regimes will be described.

Benefits and Learning Objectives
This course should enable you to:

• Describe the fundamentals of high power fiber lasers and amplifiers.
• List key strengths and relative merits of high power fiber lasers and amplifiers.
• Assess performance limitations and describe the underlying physical reasons in different operating regimes.
• Design or specify basic fiber properties for specific operating regimes.
• Describe the possibilities, limitations, and implications of current technology regarding core size and rare earth concentration of doped fibers.
• Discuss different options for suppressing stimulated Brillouin scattering and other detrimental nonlinearities.
• Design basic high power fiber lasers and amplifier systems.
• List strengths and weaknesses of different pumping schemes.

Intended Audience
This course is intended for scientists and engineers involved or interested in commercial and military high power fiber systems. This includes system designers, laser designers and fiber fabricators. A basic knowledge of fibers and lasers is needed.

Instructor Biography
Johan Nilsson is a professor in the Optoelectronics Research Centre (ORC), University of Southampton, England. He received a doctorate in engineering sciences from the Royal Institute of Technology, Stockholm, Sweden, in 1994, for research on optical amplification. Since then, he has worked on optical amplifiers and amplified lightwave systems, optical communications, guided-wave lasers and nonlinear optics, first at Samsung Electronics and now at the ORC, where he is leading a research group in the field of high-power fiber devices and applications. His research has primarily focused on devices but has also covered system, fabrication and materials aspects. He has given courses on high-power fiber sources at Photonics West and OFC.