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Physical Sciences and Mathematics Commons™
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Full-Text Articles in Physical Sciences and Mathematics
Single Molecule Emission Characteristics In Near-Field Microscopy, Randy X. Bian, Robert C. Dunn, X. Sunney Xie, P.T. Leung
Single Molecule Emission Characteristics In Near-Field Microscopy, Randy X. Bian, Robert C. Dunn, X. Sunney Xie, P.T. Leung
Physics Faculty Publications and Presentations
In near-field scanning optical microscopy (NSOM), the measured fluorescence lifetime of a single dye molecule can be shortened or lengthened, sensitively dependent on the relative position between the molecule and aluminum coated fiber tip. The modified lifetimes and other emission characteristics are simulated by solving Maxwell equations with the finite-difference time-domain (FDTD) method. The 2D computation reveals insight into the lifetime behaviors and provides guidance for nonperturbative spectroscopic measurements with NSOM. This new methodology is capable of predicting molecular emission properties in front of a metal/dielectric interface of arbitrary geometry.
Origins And Effects Of Thermal Processes On Near-Field Optical Probes, Andres H. La Rosa, B. I. Yakobson, H. D. Hallen
Origins And Effects Of Thermal Processes On Near-Field Optical Probes, Andres H. La Rosa, B. I. Yakobson, H. D. Hallen
Physics Faculty Publications and Presentations
An aluminum-coated tapered fiber probe, as used in near-field scanning optical microscopy (NSOM), is heated by the light coupled into it. This can destroy the probe or may modify the sample, which can be problematic or used as a tool. To study these thermal effects, we couple modulated visible light of various power through probes. Simultaneously coupled infrared light senses the thermal effects. We report their magnitude, their spatial and temporal scales, and real-time probe damage observations.Amodel describes the experimental data, the mechanisms for induced IR variation, and their relative importance.