By use of the reflection of an uncoated external etalon, a diode-pumped thulium-doped YAG microchip laser was forced into a single-frequency mode. The wavelength of the single-frequency radiation was tunable over 15 nm simply by translation of the etalon relative to the laser. Output powers of 45 mW were achieved in a monolithic setup that is insensitive to vibrations. The origin of the single-frequency oscillation is the wavelength-dependent reflection of the etalon, which is coupled back into the laser resonator. This method permits the combination of inherently stable, single-frequency resonator geometries such as microchips with laser materials that have broad tuning ranges.
© 1998 Optical Society of America
(140.0140) Lasers and laser optics : Lasers and laser optics
(140.3480) Lasers and laser optics : Lasers, diode-pumped
(140.3570) Lasers and laser optics : Lasers, single-mode
(140.3580) Lasers and laser optics : Lasers, solid-state
(350.5610) Other areas of optics : Radiation
Frank F. Heine and Günter Huber, "Tunable Single Frequency Thulium:YAG Microchip Laser With External Feedback," Appl. Opt. 37, 3268-3271 (1998)