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Information × Registration Number 0219U102019, 0115U006686 , R & D reports Title Investigation of optical methods of vizualization and positioning nanosize objects. popup.stage_title Head Chadiuk Viacheslav O., Registration Date 13-12-2019 Organization Publishing and Printing Institute of Igor Sikorsky Kyiv Polytechnic Institute popup.description2 The forces acting on the nanoparticle located near the focus (waist) of the laser beam are considered. Based on the analysis of the forces acting on the dielectric nanoparticle near the laser Gaussian beam waist, a mathematical model of the optical tweezers was constructed and the formation of an optical trap capable of trapping and holding the particle was demonstrated. The calculations showed that in a focused laser beam the gradient force outweighs the scattering force and is only compared to it in the immediate vicinity of the focus. The equilibrium conditions of the nanoparticle in the focused laser beam were found. The influence of Brownian motion of medium (water) molecules on the positioning accuracy of nanoparticles is considered. It was found that a particle of 10 nm radius, which is in water, for 10 ms can be at a distance of 1 μm from its initial position, if it is not affected by any forces. It has been confirmed that the motion of a particle in a medium with a non-zero viscosity occurs at a constant velocity and depends on the particle radius and radiation intensity within the cross section of the particle. The velocity value of a particle obtained on the basis of the developed mathematical model of optical tweezers, with high accuracy, coincides with the value found by the inventor of optical tweezers American physicist Arthur Ashkin in 1969. The possibility of using an optical tweezers with a dielectric nanoparticle in its trap as a sensor of physical and chemical quantities that influence the refractive index of the medium is investigated. A method for measuring the size of a nanoparticle by the power of its scattered laser radiation, as well as the design of the measuring system, is proposed. Using the model it is shown that a local change in the density of the medium by 3% causes the nanoparticle to move by 1 nm. The state of nanoscopy development using electron microscopy and the types of scanning probe microscopy – tunneling microscopy, atomic   Product Description popup.authors Chadyuk Vyacheslav popup.nrat_date 2020-04-02 Close