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Proceedings Paper

Assigning error to an M2 measurement
Author(s): T. Sean Ross
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Paper Abstract

The ISO 11146:1999 standard has been published for 6 years and set forth the proper way to measure the M2 parameter. In spite of the strong experimental guidance given by this standard and the many commercial devices based upon ISO 11146, it is still the custom to quote M2 measurements without any reference to significant figures or error estimation. To the author's knowledge, no commercial M2 measurement device includes error estimation. There exists, perhaps, a false belief that M2 numbers are high precision and of insignificant error. This paradigm causes program managers and purchasers to over-specify a beam quality parameter and researchers not to question the accuracy and precision of their M2 measurements. This paper will examine the experimental sources of error in an M2 measurement including discretization error, CCD noise, discrete filter sets, noise equivalent aperture estimation, laser fluctuation and curve fitting error. These sources of error will be explained in their experimental context and convenient formula given to properly estimate error in a given M2 measurement. This work is the result of the author's inability to find error estimation and disclosure of methods in commercial beam quality measurement devices and building an ISO 11146 compliant, computer- automated M2 measurement device and the resulting lessons learned and concepts developed.

Paper Details

Date Published: 22 February 2006
PDF: 7 pages
Proc. SPIE 6101, Laser Beam Control and Applications, 610108 (22 February 2006); doi: 10.1117/12.640434
Show Author Affiliations
T. Sean Ross, Air Force Research Lab. (United States)

Published in SPIE Proceedings Vol. 6101:
Laser Beam Control and Applications
Steven J. Davis; Alexis V. Kudryashov; Adolf Giesen; Detlef Nickel; Michael C. Heaven; Alan H. Paxton; Vladimir S. Ilchenko; J. Thomas Schriempf, Editor(s)

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