We show experimentally that the combination of soft-edged gain and index guiding can lead to resonant excess quantum noise. Resonances with excess noise factors close to 100 are observed in end-pumped Nd<sup>3+</sup>:YVO<sub>4</sub> lasers for cavity lengths in which two modes experience similar gain. An associated increase in the relaxation oscillation damping rate demonstrates that the fluctuation enhancement is indeed caused by excess quantum noise and not by dynamic instabilities.
© 2003 Optical Society of America
(140.0140) Lasers and laser optics : Lasers and laser optics
(140.3410) Lasers and laser optics : Laser resonators
(140.3530) Lasers and laser optics : Lasers, neodymium
(230.7370) Optical devices : Waveguides
(270.2500) Quantum optics : Fluctuations, relaxations, and noise
Y. Lien, E. van der Togt, M. P. van Exter, J. P. Woerdman, and N. J. van Druten, "Resonant excess quantum noise in lasers with mixed guiding," Opt. Lett. 28, 1668-1670 (2003)