SC157 - Laser Beam Analysis, Propagation, and Shaping Techniques
Sunday, 14 May
13:30 - 17:30
Short Course Level: Beginner
Instructor: James Leger; Univ. of Minnesota, USA
Short Course Description:
The performance of conventional high power lasers is often compromised by one or more physical effects, limiting the maximum power that can be obtained from a single lasing element. To increase the power from these individual elements, laser beam combining can be employed to convert the outputs from several lower-power modules into a single, high-power beam. This short course establishes general beam combining principles relevant to all laser systems, and emphasizes the limits that are achievable with differ approaches. The practicing engineer and technical manager will be introduced to a wide variety of beam combining methods. Incoherent beam combining attempts to maximize the radiance of an array of incoherent sources. The theoretical limits of this approach will be derived, and a design methodology developed to achieve maximum radiance. Spectral and polarization beam combining techniques employ wavelength and polarization sensitive elements to sum laser power. Several practical issues of this technique will be discussed, and specific systems described. Coherent beam combining is introduced by exploring methods of establishing mutual coherence across laser arrays. The properties and characteristics of these coherent techniques are quantitatively analyzed using simple modal theories. Methods of converting arrays of coherent beams into a single beam are explored, and the sensitivity of these approaches to path length errors investigated. Real-world examples will be used as case studies to illustrate design principles. This offering of the course will make use of recently developed material on coherent beam combining architectures.
Short Course Benefits:
This course should enable the participants to:
Describe the requirements for laser beam combining of all types.
Estimate the optimum brightness enhancement achievable from incoherent combining.
Design an ideal incoherent beam combiner.
Design spectral beam combiners and estimate performance limitations.
Compare different architectures for establishing mutual coherence across laser arrays.
Determine the effects of path length errors on beam combining performance.
Design optical systems to convert coherent arrays of laser beams into a single beam.
Describe the performance characteristics of several laser systems that utilize beam combining.
Short Course Audience:
The course is designed for students, engineers, scientists and technical managers who are interested in understanding the basics of laser beam combining. No advanced knowledge of laser systems is assumed.
James Leger is the Cymer Professor of Electrical and Computer Engineering at the University of Minnesota. His previous work at MIT Lincoln Laboratory and current research concerns diffractive and microoptics applied to lasers and electro-optic systems. Prof. Leger is a fellow of OSA, IEEE, and SPIE, and winner of the 1998 OSA Fraunhofer award. He is also a member of the academy of distinguished teachers, and has won several awards for his teaching. Current and past service includes Deputy Editor of Optics Express and membership on the OSA board of directors.