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Optical heterodyne force microscopy
1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102), 2002We present a new technique, Optical Heterodyne Force Microscopy, that allows local probing of photothermally-induced ultrasonic vibrations of a sample surface. We demonstrate with images of a sample of highly-oriented pyrolytic graphite obtained at megahertz optical modulation frequencies that lateral resolution of surface and subsurface variations in ...
Kumano, N. +3 more
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Optical pressure and numerical simulation of optical forces
Applied Optics, 2017Optical forces on a particle can be calculated using numerical methods and by integrating the Maxwell stress tensor over the surface of the particle. It is shown that this gives considerable numerical noise for the radiation force on particles with refractive index close to that of the surrounding medium and that a large number of mesh elements are ...
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Force-balancing force sensor with an optical lever
Review of Scientific Instruments, 1995Scanning force microscopes (SFMs) are sometimes used to obtain a force curve, which shows the force variation as a function of tip–sample distance. In the force curve measurement, if the spring constant of the force detecting lever is small, the measured force curve has discontinuity and is different from the true force curve. In this paper, we present
Nobuhiro Kato +3 more
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Optical force field mapping in microdevices
Lab Chip, 2006We present a method for characterizing microscopic optical force fields. Two dimensional vector force maps are generated by measuring the optical force applied to a probe particle for a grid of particle positions. The method is used to map out the force field created by the beam from a lensed fiber inside a liquid filled microdevice. We find transverse
Knoener, Gregor +5 more
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Force–Spectrum Relations for Molecular Optical Force Probes
Angewandte Chemie International Edition, 2014AbstractForce probes allow real‐time monitoring of forces acting in different regions of large molecules and are potentially suited for the investigation of structural changes occurring in macromolecules during, e. g., folding processes.1–10 Such information is crucial for the understanding of mechanochemical reactivity.2, 3, 6, 7 To this end, small ...
Andreas Dreuw, Tim Stauch
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Magnus force effect in optical manipulation
Physical Review A, 2011The effect of the Magnus force in optical micromanipulation has been observed. An ad hoc experiment has been designed based on a one-dimensional optical trap that carries angular momentum. The observed particle dynamics reveals the occurrence of this hydrodynamic force, which is neglected in the common approach.
CIPPARRONE, Gabriella +3 more
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