分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: When the quasi-phase matching (QPM) parameters of the $\chi^{(2)}$ nonlinear crystal rotate along a closed path, geometric phase will be generated in the signal and idler waves that participate in the nonlinear frequency conversion. In this paper, we study two rotation schemes, full-wedge rotation, and half-wedge rotation, of the QPM parameters in the process of fully nonlinear three-wave mixing. These two schemes can effectively suppress the uncertainty in creating the geometric phase in the nonlinear frequency conversion process when the intensity of the pump is depleted. The finding of this paper provides an avenue toward constant control of the geometric phase in nonlinear optics applications and quantum information processing.
分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: We report solutions for stable compound solitons supported by a three-dimensional (3D) quasi-phase-matched (QPM) photonic crystal in a medium with the quadratic ($\chi ^{(2)}$) nonlinearity. The photonic crystals are introduced with a checkerboard structure, which can be realized by means of the available technology. The solitons are built as four-peak vortex modes of two types, rhombuses and squares. Their stability areas are identified in the system's parametric space, while all bright vortex solitons are subject to strong azimuthal instability in uniform $\chi ^{(2)}$ media. Possibilities for experimental realization of the solitons are outlined too.