Compact method for optical induction of proximal probe heating and elongation

A tapered, metal-coated, optical fiber probe will elongate when heated by light input through a fiber. The induced motion can be used for data storage or nanostructuring of a surface. The elongation produced by this alignment-free system is measured with force feedback in a near-field scanning optical microscope (NSOM). The input light intensity controls the elongation magnitude, which ranges from a few nanometers to more than 100 nm. A 0.5-mW input energy yields approximately 20 nm of probe elongation. The elongation quantified here can create artifacts in any experiment using pulsed laser light with a NSOM or an atomic force microscope.