Thermal processes in metal-coated fiber probes for near-field experiments

We have used a ray optics model to calculate the optical power absorbed in the metal coating of apertured probes for scanning near-field optical microscopy. We have then introduced the absorbed power profile into the heat balance equation to calculate the temperature of the probe as a function of the distance from the apex. By comparing our results with available experimental data, we demonstrate accurate prediction of both the temperature profile along the probe, and the temperature increase per mW of power launched into the fiber (60.7 versus 60 K/mW at 25 mu m from the apex). (c) 2005 American Institute of Physics.