Generation of reconfigurable two-dimensional photorefractive photonic heterostructures with composite periods using multi-lens boards

• We fabricate composite periodic microstructures in LiNbO3:Fe crystal for the first time.
• The experimental setup is very simple and flexible.
• The period of the composite periodic lattices can be dominated easily.
• The composite periodic lattices can exist stably for a long time in the crystal.
• Other more complex photonic microstructures can be fabricated with this method.

A convenient approach to generate two-dimensional photorefractive photonic heterostructures with composite periods was experimentally demonstrated by multi-lens boards. The approach is pretty simple and does not require any complicated optical adjustment as the conventional methods did. Two kinds of composite periodic lattice structures are numerically simulated and optically induced inside an iron-doped lithium niobate photorefractive crystal. The induced composite photonic microstructures can be fixed or erased even re-recorded in the photorefractive crystal, which suggests potential applications in nonlinear photonic devices. Numerical simulation illustrates that the method can be easily extended to form more complex photonic microstructures by designing the multi-lens board appropriately.