Interaction of strong laser beam with He-atom using non-perturbative Floquet method

Non-perturbative Floquet method is used to investigate the interaction of strong linearly polarized light with He-atom. In the calculations, six lowest singlet target states and fifteen photon states are taken for absolute convergence. For allowed transitions, accurate oscillator strengths using configuration interaction wave-functions are used. A number of interesting features such as nonlinear effects at high intensities, line broadening, a dynamic Stark effect are obtained and explained.