Optimization design of aperiodic optical superlattices for harmonic generations

Abstract

We present the optimization design of aperiodic optical superlattices (AOSs) realized by inverting poled ferroelectric domains in sample. This design problem belongs to solving an inverse source problem in nonlinear optics. The optical design of the AOS can be achieved with use of the simulated annealing method. The constructed AOSs can implement multiple wavelength second-harmonic generation and the coupled third-harmonic generation with an identical effective nonlinear coefficient, at the preassigned wavelengths. The simulations show that the harmonic generations in the constructed AOSs can approach the prescribed goal better than those with the Fibonacci optical superlattice. The effective nonlinear coefficients vs the optical wave propagating distance from the impinging surface of incident light in samples exhibit monotonically increasing behavior. This clearly infers that the contribution form every block to the otpical parametric processes is with each other in the constructive interference state. It is expected that this new design method may provide an effective and useful technique for flexibly constructing nonlinear optical material to achieve the desired functions and match various practical applications.