Theoretical study of the electro-optic effect of aperiodically poled lithium niobate in a Q-switched dual-wavelength laser

The electro-optic effect of aperiodically poled lithium niobate (APLN) has been theoretically investigated and proposed to use as a Q-switch in a simultaneous dual-wavelength laser. Our analysis shows that the polarization planes of the z-polarized (or y-polarized) dual-wavelength beams can be simultaneously rotated by 90° through a well-constructed APLN with an external electric field applied along the y-axis, which enables Q-switch function in a dual-wavelength laser cavity. Using a Nd:YVO4 laser operating at 1.0643 μm and 1.3419 μm as an example, we present a design method of APLN by using the so-called simulated annealing algorithm. The influence of the domain errors in fabricating an APLN device is also studied. The results show that the device is not susceptible to the fabrication errors.