SC270 High Power Fiber Lasers and Amplifiers

Tuesday, May 6, 8:30 a.m. - 12:30 p.m.
W. Andrew Clarkson; Optoelectronics Res. Ctr., Univ. of Southampton, UK

Course Description
Recent advances in cladding-pumped fiber lasers and amplifiers have been dramatic, leading to unprecedented levels of performance in terms of output power, efficiency, beam quality and wavelength coverage. These achievements have attracted growing interest within the community and have fuelled thoughts that fiber-based sources may one day replace conventional “bulk” solid-state lasers in many application areas. The main attractions of cladding-pumped fiber sources are derived directly from their geometry which simultaneously allows very efficient generation of coherent light and almost complete immunity from the effects of heat generation, which are so detrimental to the performance of other types of lasers.

This course aims to provide an introduction to high power fiber lasers and amplifiers, starting from the basic principles of operation and ending with examples of current state-of-the-art devices and some thoughts on future prospects. The course will cover a range of topics, including basic fiber laser and amplifier theory, spectroscopy of the relevant rare earth ions for high power devices, a discussion of the factors influencing laser and amplifier performance, fiber design and fabrication, pump sources and pump launching schemes, fiber resonator design, master-oscillator and power-amplifier configurations, linewidth control and wavelength selection, transverse mode selection, nonlinear loss processes (SBS and SRS) and their impact on performance, and heat generation and its impact on power scalability. The course will also give an overview of techniques (e.g. coherent and spectral beam combining) for further scaling of output power and provide an introduction to hybrid fiber-bulk laser schemes for scaling pulse energy.

Benefits and Learning Objectives
This course should enable you to:

• Calculate threshold pump power and slope efficiency, and estimate the maximum output power that can be obtained from a given fiber laser oscillator or amplifier configuration.
• Select the optimum pump source for a given rare earth ion transition and fiber design.
• Design the pump light collection and coupling scheme and estimate the pump launch efficiency.
• Specify the fiber parameters (e.g. cladding design, core size, rare earth ion concentration) required for a particular laser or amplifier configuration.
• Design the fiber laser resonator and select the operating wavelength.
• Estimate thermally-induced damage limit.
• Measure fiber laser performance characteristics and relate these to fiber design and resonator parameters.

Intended Audience
This course is intended for individuals with a basic knowledge of lasers and optics who wish to learn about the basic principles and capabilities of fiber lasers and amplifiers when operating at high power levels. The course will also cover some of the practical issues of operating these devices and provide an update for those wishing to learn about some of the latest developments in this rapidly advancing field.

Instructor Biography
W. Andrew Clarkson obtained his bachelor of science degree in physics from the University of Manchester (United Kingdom) in 1984 and his doctorate from the University of Southampton (United Kingdom) in 1991. He currently holds the position of professor at the Optoelectronics Research Centre, University of Southampton, where he leads a research group investigating power-scaling of fiber lasers and solid-state lasers, and nonlinear frequency conversion schemes for these devices. He has presented and co-authored numerous invited papers in this area and has published more than 200 journal and conference papers. He has served on the technical program committees of numerous international conferences, and as a topical editor for Optics Letters and is a fellow of the Optical Society of America.