In lasers with nonorthogonal eigenmodes the excess-noise factor <i>K</i> can be large, especially in unstable-cavity lasers with hard-edged intracavity apertures. To the best of our knowledge, we report the first detailed study of the dependence of <i>K</i> on aperture shape. Calculations and measurements of <i>K</i> for unstable-cavity lasers with variable-size apertures of triangular, square, pentagonal, hexagonal, octagonal, and rhomboid symmetries are summarized. It is shown that both the magnitude of <i>K</i> and its resonant behavior strongly depend on aperture shape and that many aspects of this dependence can be explained in terms of one-dimensional resonance lengths.
© 1999 Optical Society of America
(050.1220) Diffraction and gratings : Apertures
(050.1940) Diffraction and gratings : Diffraction
(140.3460) Lasers and laser optics : Lasers
(270.2500) Quantum optics : Fluctuations, relaxations, and noise
(270.3430) Quantum optics : Laser theory
G. P. Karman, G. S. McDonald, J. P. Woerdman, and G. H. C. New, "Excess-Noise Dependence on Intracavity Aperture Shape," Appl. Opt. 38, 6874-6878 (1999)