The stability of the output light from a diode-pumped intracavity frequency-doubled Nd:YAG laser was studied. An intracavity nonlinear crystal, such as Type II phase-matched potassium titanyl phosphate, was used for frequency doubling. The incident beam consisted of two orthogonal linearly polarized modes. When the polarization eigenvectors were parallel to the E and O axes of the crystal, a large amplitude fluctuation was observed; however, when the azimuthal angle between the polarization eigenvectors and the axis was 45°, the light output was stabilized. The experimental results are explained by analyzing the coupling of the two orthogonal linearly polarized modes through a sum-frequency-generation process.
© 1988 Optical Society of America
Original Manuscript: March 23, 1988
Manuscript Accepted: June 29, 1988
Published: October 1, 1988
Michio Oka and Shigeo Kubota, "Stable intracavity doubling of orthogonal linearly polarized modes in diode-pumped Nd:YAG lasers," Opt. Lett. 13, 805-807 (1988)