Figure 1
From: Dielectric Optical-Controllable Magnifying Lens by Nonlinear Negative Refraction
Illustration of the magnifying lens by nonlinear 4 WM.
a, Schematic of negative refraction realized by the 4 WM process in a thin planar glass slide. In a special case when the pump beam at frequency ω1 is incident normally on the glass slide, the generated 4 WM beam at frequency ω3 will be refracted negatively with respect to the angle of the probe beam at frequency ω2. b, The phase matching condition for the degenerate 4 WM process in 3D wave vector space. The dashed ring line indicates the joint points of wave vector k2 and k3 that fulfill the phase matching condition: 2k1 − k2 − k3 = 0. c, Schematic of the experimental setup of the magnifying lens by 4 WM. The probe beam at ω2 that carries the object information can nonlinearly mix with the pump beam at ω1 in a plano-concave lens to give rise to the 4 WM beam which can form the magnified image of the object.
