Near-field scanning optical microscopy probes with heat sinks for higher power operations

Abstract

The metal coating of a near field scanning optical microscope (NSOM) probe will melt when a few mW of laser light is introduced into the fiber. For higher power operation a process to coat the tip of the NSOM probe with epoxy without damaging the probe was developed. The tip protrudes no more than a few micron outside the epoxy surface such that the evanescent wave from the tip is still available for applications. The epoxy heat sink dissipates heat away from the NSOM probe keeping the metal coating cooler, which allows the input laser power to be increased to 21.4 mW at a wavelength of 405 nm without damaging the NSOM probe.