title: Interaction of Gaussian beam with near-spherical particle: an analytic-numerical approach for assessing scattering and stresses.
abstract: We derive a straightforward theoretical method to determine the electromagnetic fields for the incidence of a monochromatic laser beam on a near-spherical dielectric particle. The beam-shape coefficients are obtained from the radial laser fields and expressed as a finite series in a form that has, to our knowledge, not been published before. Our perturbation approach to solve Maxwell's equations in spherical coordinates employs two alternative techniques to match the boundary conditions: an analytic approach for small particles with low eccentricity and an adapted point-matching method for larger spheroids with higher aspect ratios. We present results for the internal and external fields, scattering intensities, and stresses exerted on the particle. While similarly accurate as others, our approach is easily implemented numerically and thus particularly useful in praxis, e.g., for analyzing optical traps, such as the optical stretcher.
authors: Sector for Biological and Soft Systems, Department of Physics, University of Cambridge, Cambridge, UK.
authors: Lars
authors: L
authors: Boyde
authors: Kevin J
authors: KJ
authors: Chalut
authors: Jochen
authors: J
authors: Guck
mesh_terms: D017097:Electric Impedance; D004574:Electromagnetic Fields; D007834:Lasers; D008956:Models, Chemical; D016011:Normal Distribution; D052898:Optical Tweezers; D012542:Scattering, Radiation