Aperiodic 1-dimensional structures for quasi-phase matching.

We describe a method for designing 1-dimensional aperiodic poled grating structures of finite length that quasi-phase match multiple Chi((2)) processes. The poling functions for such gratings are best aligned, in terms of the dot product in Fourier space, with a design target. No restrictions are placed on the quasi-phase matching wave numbers. A grating designed for third harmonic generation is simulated.