Laser Physics Center, Research School of Physics and Engineering, Australian National University, ACT 0200, Australia.
Opt Lett. 2010 Nov 15;35(22):3790-2. doi: 10.1364/OL.35.003790.
We report simultaneous generation of multiple conical second-harmonic waves in a two-dimensional nonlinear photonic structure when illuminated by two overlapping noncollinear fundamental beams. We show that this phenomenon is caused by the nonlinear Čerenkov radiation emitted due to the interaction of photons from each constituent fundamental beam as well as the virtual one propagating along the bisector of the two beams. In addition, by studying the asymmetric geometry of the interaction, we uniquely verify the effects of reciprocal vectors on the Čerenkov-type second-harmonic generation in nonlinear photonic structures.
我们报告了在二维非线性光子结构中，当用两束重叠的非共线基频光束照射时，同时产生多个圆锥二次谐波波。我们表明，这种现象是由每个组成基频光束以及沿着两束光的平分线传播的虚拟光的相互作用引起的非线性切伦科夫辐射引起的。此外，通过研究相互作用的非对称几何形状，我们独特地验证了在非线性光子结构中，倒易矢量对切伦科夫型二次谐波产生的影响。
