Digitally reconfigurable complex 2D Dual lattice structure by optical phase engineering

We present a method to combine two periodic lattice wave-fields to generate a complex dual lattice wave-field which could be employed for microfabrication of corresponding 2D dual lattice structures. Since the addition of two periodic lattice wave-fields is coherent in nature the resultant dual lattice structure is highly dependent on the relative phase difference between constituent wave-fields. We show that it is possible to have control over the dual lattice pattern by precisely controlling this relative phase difference. This control is enabled by making use of digitally addressable phase only spatial light modulator (SLM). We provide the computational method for calculation of corresponding phase mask to be displayed on the SLM and also verify the results experimentally by employing a simple 4f Fourier filter based geometry. The method is completely scalable and reconfigurable in terms of the choice of periodic lattice wave-fields and has the potential to form gradient phase masks which could be useful for fabrication of graded index optical components.