Mode characteristics investigations on a side pumped electro-optic Q-switched Nd:YAG laser

The influence of representative aberration on the performance of a side pumped electro-optic Q-switched Nd:YAG lasers was demonstrated. The spatial and temporal behavior of the laser with intracavity disturbation was modeled using a numerical calculation of the diffraction integral equations and then experimentally characterized. The eigenmode properties, including the coaxial state with thermal effect of the active medium and geometric misalignment of the cavity OC mirror have been analyzed. Zernike polynomials are further adopted to describe beam distortions by combining the model wavefront reconstruction. Experiment illustrates that the lower-order Zernike aberration such as Z3, Z4 Z5 and Z10, etc. caused by the typical phase disturbation will significantly affect the mode characteristics and the uniform symmetry of wavefront. Other related beam properties e.g. PSF can also be acquired by further calculation. In addition, the proposed method has the merit of working stability and high efficiency. Corresponding strategies are suggested to consider active compensation of intracavity aberration in such lasers.