NEAR-FIELD OPTICAL THERMOMETRY

Far-field optical thermometry techniques have spatial resolution limit ed by diffraction to the order of the radiation wavelength. We report progress on near-field optical thermometry (NFOT) that targets spatial resolution better than 50 nm. A tapered, single-mode optical fiber sc ans nanometers above electronic microstructures, which are heated usin g transient electrical currents. The fiber rip releases about 1 nW of radiation power from a steady probe laser, and the reflected radiation is used to measure the local temperature. Simultaneous electrical res istance thermometry is used to estimate the relative importance of tem perature-dependent optical properties of the sample and thermal expans ion of the sample and tip. This work provides guidance for implementin g other NFOT techniques using radiation transmission and infrared emis sion.