We demonstrate and investigate a peculiar mode of cw Yb<sup>3+</sup>-doped crystal laser operation when two emissions, at two independently tunable wavelengths, are simultaneously produced. Both emissions are generated from a single pumped volume and take place in either a single beam or spatially separated beams. The laser employs original two-channel cavities that use a passive self-injection-locking (PSIL) control to reduce intracavity loss. The advantages of the application of the PSIL technique and some limitations are shown. The conditions for two-wavelength multimode operation of the cw quasi-three-level diode-pumped Yb<sup>3+</sup> lasers and the peculiarity of such an operation are carried out both theoretically and experimentally. The results reported are based on the example of a Yb<sup>3+</sup>:GGG laser but similar results are also obtained with a Yb<sup>3+</sup>:YAG laser. The laser operates in the 1023–1033-nm (1030–1040-nm) range with a total output power of 0.4 W. A two-wavelength, single longitudinal mode generation is also obtained.
© 2003 Optical Society of America
(140.3410) Lasers and laser optics : Laser resonators
(140.3480) Lasers and laser optics : Lasers, diode-pumped
(140.3570) Lasers and laser optics : Lasers, single-mode
(140.3600) Lasers and laser optics : Lasers, tunable
Yann Louyer, Jean-Pierre Wallerand, Marc Himbert, Margarita Deneva, and Marin Nenchev, "Two-Wavelength, Passive Self-Injection-Controlled Operation of Diode-Pumped cw Yb-Doped Crystal Lasers," Appl. Opt. 42, 5463-5476 (2003)