Static interference fringes were observed repeatedly with changes of path difference in both homodyne and heterodyne Michelson interferometers. This unique coherence property of an electronically tuned Ti:sapphire laser with an intracavity acousto-optic tunable filter (AOTF) has revealed the frequency structure and dynamics of the laser field. The fact that static interference occurred in a heterodyne interferometer with unequal path lengths indicates backscattering of the intracavity laser field, suggesting that Brillouin-enhanced four-wave mixing occurs in the intracavity AOTF.
© 1999 Optical Society of America
(040.2840) Detectors : Heterodyne
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(140.3590) Lasers and laser optics : Lasers, titanium
(190.0190) Nonlinear optics : Nonlinear optics
(190.2640) Nonlinear optics : Stimulated scattering, modulation, etc.
(230.1040) Optical devices : Acousto-optical devices
Jihong Geng, *Satoshi Wada, Norihito Saito, and Hideo Tashiro, "Frequency structure in an electronically tuned Ti:sapphire laser: periodic appearance of static fringes in both homodyne and heterodyne Michelson interferometers," Opt. Lett. 24, 1635-1637 (1999)