Max-Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
Opt Lett. 2010 May 1;35(9):1317-9. doi: 10.1364/OL.35.001317.
We analyze the conical second-harmonic generation via Cerenkov-type phase matching in two-dimensional decagonal nonlinear photonic quasi-crystals for linear, circular, and elliptical polarized fundamental beams. Depending on the polarization state, we observe either centrosymmetric or noncentrosymmetric intensity modulation of the second-harmonic rings. We explain this effect by employing the concept of effective quadratic nonlinearity combined with the hexagonal symmetry of the individual ferroelectric domains.
我们分析了通过二维十次非线性格栅的切伦科夫型相位匹配的锥形二次谐波产生，对于线性、圆偏振和椭圆偏振的基频光束。根据偏振状态，我们观察到二次谐波环的对称或非对称强度调制。我们通过有效二次非线性的概念结合各铁电畴的六边形对称性来解释这种效应。
