In the framework of generalized Lorenz-Mie theory, laser beams are described by sets of beam-shape coefficients. The modified localized approximation to evaluate these coefficients for a focused Gaussian beam is presented. A new description of Gaussian beams, called standard beams, is introduced. A comparison is made between the values of the beam-shape coefficients in the framework of the loca...

A previously developed theoretical procedure for determination of electromagnetic fields associated with the interaction of a higher-order Gaussian beam with a homogeneous spherical particle is used to investigate the effects of incident beam type on far-field scattering. Far-field scattering patterns are calculated for (0,0), (0,1), and (1,1) mode Hermite-Gaussian beams and for the helix dough...

The differential equation for the fourth-order statistical moment of the field of a finite beam propagating in a statistically homogeneous and isotropic two-dimensional random medium is solved numerically. Results are presented for the variance and covariance of irradiance scintillations of a Gaussian beam that propagates in a medium with a Gaussian correlation function. It is shown that the ra...

An overview of Gaussian beam imaging is given for converted and surface reflected seismic waves. The earthquake seismology community now regularly uses seismic waves from distant sources to illuminate structures beneath seismic arrays in so-called passive imaging experiments. Similarly, reservoir structures can be imaged with seismic waves incident from below using sources in boreholes. Gaussia...

Light beams with extraordinary spatial structures, such as the Airy beam (AB), the Bessel-Gaussian beam (BGB) and the Laguerre-Gaussian beam (LGB), are widely studied and applied in many optical scenarios. We report on preparation of light beams with controllable spatial structures through sum frequency generation (SFG) using two Gaussian pump beams in a quasi-phase matching (QPM) crystal. The ...

We investigate the generation of amplitude-squeezed states with degenerate optical parametric amplifiers that are pumped by focused Gaussian beams. We present a model that facilitates the calculation of the squeezing level for an experimentally realistic configuration in which there is a Gaussian input signal beam that has the same confocal parameter and waist location as the Gaussian pump beam...

The purpose of this paper is control of simply supported flexible core sandwich beam's linear vibration equipped with piezoelectric patches under different loads. The effects of external forces imposed on sandwich beam can be reached to a minimum value by designing an appropriate controller and control the beam's vibration. Three-layer sandwich beam theory is used for analytical modeling of san...

In this paper, we give a review of the tensor method for treating the propagation of scalar and electromagnetic Gaussian Schell-model (GSM) beams. Partially coherent complex curvature tensor is introduced to describe a scalar astigmatic partially coherent GSM beam with twisted phase (i.e., twisted anisotropic GSM beam). A tensor ABCD law for treating the propagation of scalar twisted anisotropi...

We study the reflection of a tightly focused Gaussian beam off a near symmetric resonant tunneling structure comprising two identical coupled waveguides. The coupled waveguides are loaded on each side by a spacer layer and a high index prism. Reflection of a Gaussian beam from such a resonant structure is associated with beam distortion and even beam splitting. We start with the distortion of t...