We demonstrate that the transverse eigenmodes in a waveguide that combines a parabolic index guide with a Gaussian gain guide can be highly nonorthogonal. The excess-noise factor K that arises from this nonorthogonality exhibits resonant features with maximum values that can easily reach K≈400 . This simple model applies directly to stable-cavity microchip lasers with focused gain.
© 2001 Optical Society of America
N. J. van Druten, M. P. van Exter, and J. P. Woerdman, "Resonant excess quantum noise in focused-gain lasers," Opt. Lett. 26, 1176-1178 (2001)