We study the effect of nonparaxiality in a folded resonator by accurate measurements of the Gouy phase as a function of the mode number for mode numbers up to 1500. Our experimental method is based on tuning the resonator close to a frequency-degenerate point. The Gouy phase shows a nonparaxial behavior that is much stronger in the folding plane than in the perpendicular plane. Agreement with ray-tracing simulations is established, and a link with aberration theory is made.
© 2004 Optical Society of America
(080.1010) Geometric optics : Aberrations (global)
(120.2230) Instrumentation, measurement, and metrology : Fabry-Perot
(140.4780) Lasers and laser optics : Optical resonators
(230.7370) Optical devices : Waveguides
Thijs Klaassen, Arthur Hoogeboom, Martin P. van Exter, and J. P. Woerdman, "Gouy phase of nonparaxial eigenmodes in a folded resonator," J. Opt. Soc. Am. A 21, 1689-1693 (2004)