Influence of the Talbot effect on the loss permutations of Fabry–Perot resonator modes

The loss permutations of Fabry–Perot resonator modes caused by the harmonic spatial perturbation of the radiation phase on one of the mirrors are studied numerically. The periods and amplitudes of perturbations are found at which the second or third mode in the eigenvalue modulus becomes the first mode. It is shown that in the case of perturbations with the period l₀, at which the Talbot length is equal to the double resonator length, the permutations are caused by an increase in the losses of the fundamental mode. It is also shown that the perturbation amplitudes with the period l₀, which equalise losses of the modes, depend linearly on the inverse Fresnel number F^-1.