Sub-Diffraction Light Structures in Optical Parametric Oscillators

Previously, we have proposed a method of diffraction management in optical resonators with left-handed materials. This method is now applied to parametric oscillators. We show that it is possible to engineer the sign and strength of diffraction for either the pump or signal beam – not both. We study the influence of the altered diffraction on the periodic structures and phase solitons emerging from the resonator’s output mirror. We also show that our scheme of diffraction management allows for sub-diffraction-limited structures, even if only the signal diffraction can be reduced. This effect is attributed to the homogeneity of the pump field.