This work describes the design and application of an apparatus to image aerosol particles using digital holography in a flowthrough, contact-free manner. Particles in an aerosol stream are illuminated by a triggered, pulsed laser and the pattern produced by the interference of this light with that scattered by the particles is recorded by a digital camera. The recorded pattern constitutes a digital hologram from which an image of the particles ...
The Sh-matrix elements derived from the T-matrix technique allow one to separate the shape-dependent parameters from size- and refractive-index-dependent parameters. The separation also allows the corresponding surface integrals to be solved analytically for different particle shapes. In this manuscript we give analytical expressions for the Sh-matrix elements that contain the shape information for cuboid-like particles. We find very good agreement between the results obtained using the Sh-matrix method and those ...
The refraction of a localized narrow beam is significantly different from that of a plane wave. As the beam width decreases to be in the order of the wavelength, the refraction behavior deviates noticeably from Snel's law, and when the width of a light beam is smaller than about one fifth of the wavelength of the incident light, finite-difference time-domain simulations demonstrate that refraction becomes negligible. That is, the narrow ...
We show that the far fields generated by a source inside or near a microparticle can be obtained readily by using the reciprocity theorem along with the internal or near fields generated by plane-wave illumination. The method is useful for solving problems for which the scattered fields generated with plane-wave illumination have already been obtained. We illustrate the method for the case of a homogeneous sphere, and then apply it ...
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