SC157 Laser Beam Analysis, Propagation and Shaping Techniques

Monday, May 5, 1:00 p.m. - 5:00 p.m.
James R. Leger; Univ. of Minnesota, USA

Level: Beginner (no background or minimal training is necessary to understand course material)

Course Description
The propagation and focusing properties of real laser beams are greatly influenced by beam shape, phase distortions, degree of coherence and aperture truncation effects. The ability to understand, predict and correct these real-world effects is essential to modern optical engineering. Attendees of this course will learn a variety of techniques for measuring and quantifying the important characteristics of real laser beams, be able to calculate the effects of these characteristics on optical system performance, and explore a variety of beam shaping techniques to optimize specific optical systems. The course will start with a basic description of Gaussian beam characteristics from an ideal laser. These concepts will be extended to non-Gaussian beams (e.g, top-hat shapes) and the relative merits of various beam shapes will be discussed. Beam characterization methods such as M2, Strehl ratio and TDL will be reviewed. Simple expressions for estimating the effects of laser aberrations and coherence on beam focusing and propagation will be reviewed. Coupling of light into single- and multi-mode fibers as well as far-field light concentration limits will be explored as real-world examples. The course will end with a description of internal and external cavity beam shaping techniques.

Benefits and Learning Objectives
This course should enable you to:

• Understand the characteristics of Gaussian and non-Gaussian beams in physically meaningful terms.
• Utilize specific laser beam measurement techniques, such as Strehl ratio and M2
• Calculate Gaussian beam characteristics in complex optical systems
• Analyze the effects of laser aberrations on beam propagation and focusing.
• Predict the performance limits of incoherent beam concentrators and optimize their design
• Design optimum beam couplers for fibers, solid-state pumping, etc.
• Design incoherent and coherent beam shaping optical systems
• Compare external laser cavity and internal laser cavity beam shaping techniques

Intended Audience
This course is designed to provide laser engineers, optical system designers and technical management professionals with a working knowledge of laser beam characterization, analysis and modification. Physical explanations of most topics are designed to make the concepts accessible to a wide range of students.

Instructor Biography
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, metrology, and imaging systems. Leger is a fellow of the OSA, IEEE, and SPIE, and winner of the 1998 OSA Fraunhofer Award. He is a former topical editor for Optics Express and Applied Optics, and is a past member of the Board of Directors of OSA. He is currently on the Steering Committee of CLEO.