We investigate, both theoretically and experimentally, how to build a pulsed intracavity-doubled two-frequency laser. To this aim, we use a Jones-matrix analysis in order to choose the orientations of the cavity anisotropies, namely, two quarter-wave plates, a passive Q-switch, and a doubling crystal. In particular, we find the conditions necessary for the simultaneous oscillation of the two eigenstates, depending on whether the doubling crystal is inserted between the quarter-wave plates or not. Continuous tuning of the frequency difference is provided by rotating one quarter-wave plate or the birefringent doubling crystal. Moreover, the efficiencies of second-harmonic generation and sum-frequency generation are controlled. The experimental results, obtained with a diode-pumped Nd:YAG–Cr:YAG laser intracavity doubled by a KTP crystal, are in agreement with the model.
© 2003 Optical Society of America
(140.3540) Lasers and laser optics : Lasers, Q-switched
(140.3580) Lasers and laser optics : Lasers, solid-state
(140.3600) Lasers and laser optics : Lasers, tunable
(140.7300) Lasers and laser optics : Visible lasers
(190.2620) Nonlinear optics : Harmonic generation and mixing
Ngoc Diep Lai, Marc Brunel, and Fabien Bretenaker, "Green two-frequency pulsed laser: intracavity doubling of helicoidal eigenstates," J. Opt. Soc. Am. B 20, 662-669 (2003)