Authors:
James Beil
1
;
Rebecca Swertfeger
1
;
Stephen Misak
1
;
Zihe Gao
2
;
Kent D. Choquette
2
and
Paul O. Leisher
1
Affiliations:
1
Rose-Hulman Institute of Technology, United States
;
2
University of Illinois Urbana-Champaign, United States
Keyword(s):
Beam Quality, Beam Propagation Factor, Beam Parameter Product, Diffraction-Limited, Gaussian, near-Field, Far-Field, Beam Waist, Divergence Angle, Free-Space Optical Communications, Semiconductor Laser, Diode Laser, Beam Metrics.
Related
Ontology
Subjects/Areas/Topics:
Lasers
;
Optical Communications and Networking
;
Optics
;
Photonics, Optics and Laser Technology
;
Semiconductor Lasers and Leds
;
Waveguide Lasers
Abstract:
The beam propagation factor, M2, exists as one of very few measures of a laser’s performance, when really a
more detailed analysis of the application and laser are necessary for judgement in most cases. In free-space
optical communications, a crucial figure of merit is the proportion of diffraction-limited power in the farfield.
A calculated structure has been made with a higher proportion of diffraction-limited power in the farfield
than another calculated structure with a much better M2. This calculated structure has an M2 of 19, with
89% of its power within the diffraction limit in the far-field, compared to another calculated structure with
M2 of 1.7 that has 86% of its power within the diffraction limit in the far-field.