We present a simple scheme to generate a continuously tunable pulsed narrow-bandwidth infrared wave. An Nd:YAG-pumped periodically poled lithium niobate optical parametric generator (OPG) is seeded with the output of another OPG pumped by the second harmonic (0.532 μm) of the Nd:YAG laser. A tunable idler wave from the 0.532-μm pumped OPG, operated away from the degenerate point, provides a narrow linewidth seed source for the 1.064-μm pumped broadband OPG. Seeding forces the second OPG to operate in a narrowband operation comparable with that of the seed source. Linewidth of the YAG-pumped OPG is 5–25 nm, in the tuning range of 1.61–1.83 μm (signal), narrowed to 1.48–1.05 nm. Methods of further reduction of linewidth also have been discussed.
© 2002 Optical Society of America
(140.3540) Lasers and laser optics : Lasers, Q-switched
(190.4410) Nonlinear optics : Nonlinear optics, parametric processes
(190.4970) Nonlinear optics : Parametric oscillators and amplifiers
(230.4320) Optical devices : Nonlinear optical devices
Sajjad Haidar, Takeshi Usami, and Hiromasa Ito, "Nd:YAG-Pumped Periodically Poled LiNbO3 Optical Parametric Generator Seeded with the Narrowband Output of a 532-nm Pumped Optical Parametric Generator," Appl. Opt. 41, 5656-5659 (2002)