Optically Forged Diffraction-Unlimited Ripples in Graphene

In
nanofabrication, just as in any other craft, the scale of spatial
details is limited by the dimensions of the tool at hand. For example,
the smallest details of direct laser writing with far-field light
are set by the diffraction limit, which is approximately half of the
used wavelength. In this work, we overcome this universal assertion
by optically forging graphene ripples that show features with dimensions
unlimited by diffraction. Thin sheet elasticity simulations suggest
that the scaled-down ripples originate from the interplay between
substrate adhesion, in-plane strain, and circular symmetry. The optical
forging technique thus offers an accurate way to modify and shape
2D materials and facilitates the creation of controllable nanostructures
for plasmonics, resonators, and nano-optics.