Fabrication of large area two-dimensional nonlinear photonic lattices using improved Michelson interferometer

We demonstrate an approach for easy fabrication of large area two-dimensional nonlinear photonic lattices in photorefractive crystal using the laser interference technique with an improved Michelson interferometer. The experimental setup of this method is relatively simple and inexpensive. It can be applied in almost any optical laboratories. Large area (about 28.2 mm2) two-dimensional square nonlinear photonic lattices have been produced in an iron-doped lithium niobate photorefractive crystal. We analyze the induced nonlinear photonic lattices by plane wave guiding, Brillouin-zone spectroscopy and far field diffraction pattern imaging. The period of the induced photonic lattices can be dominated easily. The induced photonic lattices can exist stably for a long time in the photorefractive crystal.