瞬态光学研究室知识库

Wepropose a novel method to reshape the light beam in a Hermiticity-tunable photonic lattice with PT symmetric perturbations. By adjusting the PT perturbations, the Hermiticity of the system varies alternatively, further resulting in the periodic oscillations of the group velocity (v(g)) as well as the group velocity dispersion (GVD). Once the values of vg and its corresponding GVD recover and the averaged group velocity ((v) over bar (g)) is zero, the light beam will be localized and recur at these Hermitian points. Further study indicates that GVD plays a key role in the evolution of the light beam, larger positive dispersion [Re(GVD)] and lower magnitude of Im(GVD) lead to higher peak energy of the light field. Our work provides a non-resonant way to control the light propagation and to reshape the group velocity distribution, which may have promising applications in all-optical circuit, optical sensor and optical communications.