Reconfigurable Nanophotonic Systems By Tunable Alignment Between Nanomagnet Arrays

We demonstrate self-alignment and tunable displacements of released nanopatterned membranes by use of arrays of nanomagnets. The nanomagnet arrays attract and align when brought into close proximity resulting in sub-200nm accurate self-alignment between membrane segments of >50mum lateral size. The alignment is made reconfigurable by patterning the nanomagnets so that there are multiple stable alignment states. An external field is used to transfer between alignment states by applying a magnetic torque on the arrays and by shifting the nanomagnet polarity. Realignment via folding and unfolding of membranes was demonstrated using 75nm thick cobalt nanomagnets patterned on lum thick silicon nitride membranes. Accurately aligned reconfigurable 2D or 3D nanophotonic systems, such as active photonic crystals and sheared photonic crystal waveguides, may be fabricated with this method.