Effective beam parameters and the turbulent beam waist for convergent Gaussian beams

1995 ◽  
Vol 34 (30) ◽  
pp. 7059 ◽  
Author(s):  
J. C. Ricklin ◽  
W. B. Miller ◽  
L. C. Andrews
Keyword(s):  
Beam Waist ◽  
Gaussian Beams ◽  
Beam Parameters ◽  
Effective Beam

scholarly journals Propagation of Vortex Hermite-Cosh-Gaussian Beams in a Gradient-Index Medium

2021 ◽  
Author(s):  
M. Lazrek ◽  
Z. Hricha ◽  
A. Belafhal
Keyword(s):  
Phase Distribution ◽  
Incident Beam ◽  
Propagation Distance ◽  
Gaussian Beams ◽  
Gradient Index ◽  
Output Beam ◽  
Propagation Equation ◽  
Intensity Pattern ◽  
Fiber Communications ◽  
Beam Parameters

Abstract Based on the Huygens–Fresnel integral, the propagation equation for a vortex Hermite-cosh-Gaussian beams (vHChGB) in gradient-index medium (GIM) is derived. From the obtained expression, the evolution of the intensity and the phase distributions of a vHChGB through a GIM are numerically demonstrated as a function of the gradient-index parameter β under the change of incident beam parameters. The results show that the characteristics of the output beam evolve periodically versus the propagation distance, and the period of evolution slows down when β is increased. Furthermore, it is demonstrated that the self-repeating properties of the intensity pattern and the phase distribution for the propagated vHChGB are altered by the incident beam parameters. The results obtained may be beneficial for applications in fiber communications and beam shaping.

Irradiance variance for convergent Gaussian beams using nondimensional beam parameters

1992 ◽  
Author(s):  
Jennifer C. Ricklin ◽  
Walter B. Miller ◽  
Larry C. Andrews
Keyword(s):  
Gaussian Beams ◽  
Beam Parameters

scholarly journals Simultaneous Trapping of Two Types of Particles with Focused Elegant Third-Order Hermite–Gaussian Beams

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 769
Author(s):  
Jingjing Su ◽  
Nan Li ◽  
Jiapeng Mou ◽  
Yishi Liu ◽  
Xingfan Chen ◽  
...  
Keyword(s):  
Focal Plane ◽  
Rayleigh Scattering ◽  
Surrounding Medium ◽  
Beam Waist ◽  
Spherical Particles ◽  
Gaussian Beams ◽  
Third Order ◽  
Radiation Forces ◽  
Dielectric Spheres ◽  
Focusing Properties

The focusing properties of elegant third-order Hermite–Gaussian beams (TH3GBs) and the radiation forces exerted on dielectric spherical particles produced by such beams in the Rayleigh scattering regime have been theoretically studied. Numerical results indicate that the elegant TH3GBs can be used to simultaneously trap and manipulate nanosized dielectric spheres with refractive indexes lower than the surrounding medium at the focus and those with refractive indexes larger than the surrounding medium in the focal vicinity. Furthermore, by changing the radius of the beam waist, the transverse trapping range and stiffness at the focal plane can be changed.

scholarly journals Effect of the turbulent biological tissues on the propagation properties of coherent Laguerre-Gaussian beams

2021 ◽  
Author(s):  
Ahmed Abdulrab Ali Ebrahim ◽  
Abdelmajid Belafhal
Keyword(s):  
Refractive Index ◽  
Biological Tissue ◽  
Propagation Distance ◽  
Biological Tissues ◽  
Gaussian Beams ◽  
Beam Spot ◽  
Spot Radius ◽  
Structural Constant ◽  
Propagation Properties ◽  
Effective Beam

Abstract In this paper, the effects of turbulent biological tissues (TBT) on the propagation properties of the coherent Laguerre-Gaussian (CLG) beams are studied. Based on the turbulence theory and using the power spectrum refractive-index model, the expression formulae of the average irradiance intensity and spreading properties of a CLG beam propagating in TBT are derived. The influence of propagation distance, beam orders, wavelengths and tissue turbulence parameters are then investigated numerically. It found that, the central dark zone of the circular/elliptical LG beams rises more rapidly as the propagation distance and the structural constant of the refractive index of the biological tissue increase and the beams become eventually more like Gaussian beams in the far-field under the influence of the turbulence biological tissues. Also, the numerical results proved that the effective beam spot radius increases as turbulence, wavelength, and propagation distance are increasing. Ultimately, the beams become circular under the influence of the turbulence of the biological tissue. As found that the effective beam spot radius along the x-axis becomes equal to that of the y-axis in high TBT which explain why an elliptical LG beam is converted into a circular one in higher structural constant of the turbulent tissue. Moreover, our results show that, the influence of the beam order m slightly greater than that of l on the beam spreading.

scholarly journals Propagation of Rectangular Multi-Gaussian Schell-Model Array Beams through Free Space and Non-Kolmogorov Turbulence

2020 ◽  
Vol 10 (2) ◽  
pp. 450 ◽  
Author(s):  
Xiaolu Ma ◽  
Dajun Liu ◽  
Yaochuan Wang ◽  
Hongming Yin ◽  
Haiyang Zhong ◽  
...  
Keyword(s):  
Free Space ◽  
Coherence Length ◽  
Gaussian Beams ◽  
Average Intensity ◽  
Beam Size ◽  
Kolmogorov Turbulence ◽  
Propagation Properties ◽  
Analytical Expressions ◽  
Effective Beam

In this paper, rectangular multi-Gaussian Schell-model (MGSM) array beams, which consists N×D beams in rectangular symmetry, are first introduced. The analytical expressions of MGSM array beams propagating through free space and non-Kolmogorov turbulence are derived. The propagation properties, such as normalized average intensity and effective beam sizes of MGSM array beams are investigated and analyzed. It is found that the propagation properties of MGSM array beams depend on the parameters of the MGSM source and turbulence. It can also be seen that the beam size of Gaussian beams translated by MGSM array beams will become larger as the total number of terms, M, increases or coherence length, σ , decreases, and the beam in stronger non-Kolmogorov turbulence (larger α and l 0 , or smaller L 0 ) will also have a larger beam size.

scholarly journals Propagation Property of an Astigmatic sin–Gaussian Beam in a Strongly Nonlocal Nonlinear Media

2018 ◽  
Vol 9 (1) ◽  
pp. 71 ◽  
Author(s):  
Kaicheng Zhu ◽  
Jie Zhu ◽  
Qin Su ◽  
Huiqin Tang
Keyword(s):  
Light Field ◽  
Propagation Distance ◽  
Gaussian Beams ◽  
Propagation Property ◽  
Nonlinear Media ◽  
Phase Singularities ◽  
Nonlocal Nonlinear Media ◽  
Strongly Nonlocal Nonlinear Media ◽  
Beam Parameters ◽  
Nonlocal Nonlinear

Based on the Snyder and Mitchell model, a closed-form propagation expression of astigmatic sin-Gaussian beams through strongly nonlocal nonlinear media (SNNM) is derived. The evolutions of the intensity distributions and the corresponding wave front dislocations are discussed analytically and numerically. It is generally proved that the light field distribution varies periodically with the propagation distance. Furthermore, it is demonstrated that the astigmatism and edge dislocation nested in the initial sin-Gaussian beams greatly influence the pattern configurations and phase singularities during propagation. In particular, it is found that, when the beam parameters are properly selected, a vortex beam with perfect doughnut-shaped profile can be obtained for astigmatic sin-Gaussian beams with two-lobe pattern propagating in SNNM.

scholarly journals Behavior of the Central Intensity of Generalized Humbert-Gaussian Beams Against the Atmospheric Turbulence

2021 ◽  
Author(s):  
Naima Nossir ◽  
Latifa Dalil-Essakali ◽  
Abdelmajid Belafhal
Keyword(s):  
Atmospheric Turbulence ◽  
Intensity Distribution ◽  
Turbulent Atmosphere ◽  
Incident Beam ◽  
Paraxial Approximation ◽  
Gaussian Beams ◽  
Central Intensity ◽  
Fresnel Integral ◽  
Special Cases ◽  
Beam Parameters

Abstract Based on the generalized Huygens-Fresnel integral in the paraxial approximation and on the Rytov theory, the analytical expression of the axial intensity distribution for the Generalized Humbert-Gaussian beams (GHGBs) propagating through a turbulent atmosphere is derived in this work. The results for the special cases of GHGBs are deduced from our study and illustrated numerically. The influence of the turbulent strength and the incident beam parameters on the propagation of these beams in the atmospheric turbulence is investigated and discussed in detail.

scholarly journals Influence of Principle Parameters on the Average Stiffness of Optical Tweezer Using Pulsed Gaussian Beams

2011 ◽  
Vol 21 (1) ◽  
pp. 71
Author(s):  
Ho Quang Quy ◽  
Hoang Dinh Hai ◽  
Hoang Van Nam
Keyword(s):  
Laser Beam ◽  
Surrounding Medium ◽  
Optical Trap ◽  
Pulsed Laser ◽  
Optical Tweezer ◽  
Beam Waist ◽  
Beam Radius ◽  
Gaussian Beams ◽  
Energy Beam ◽  
Pulsed Laser Beam

In this article expresions used to simulate the trap stiffness k of the optical trap are derived. The influence of principle parameters as total energy, beam waist and duration of pulsed laser beam, radius of dielectric particle, and viscosity of surrounding medium on the stiffness  is simulated and discussed.

scholarly journals Beam Propagation Factor of Hollow Higher-order Cosh-Gaussian Beams

2021 ◽  
Author(s):  
Faroq Saad ◽  
Ahmed Abdulrab Ali Ebrahim ◽  
Abdelmajid Belafhal
Keyword(s):  
Mathematical Model ◽  
Numerical Simulations ◽  
Beam Propagation ◽  
General Characteristic ◽  
Higher Order ◽  
Beam Waist ◽  
Gaussian Beams ◽  
Propagation Factor ◽  
Analytical Formulae ◽  
Beam Propagation Factor

Abstract Based on the second-order moments definition, we investigate in this paper the beam propagation factor of new mathematical model of Hollow higher-order Cosh-Gaussian (HhCG) beams. Two analytical formulae of the M2-factor of HhCG beams are derived. Moreover, numerical simulations are developed to illustrate the effects of the beams orders n and l, the parameter δ and the beam waist ω0 on the M2-factor. The result shows a more general characteristic of higher-order Cosh-Gaussian, Cosh-Gaussian and the fundamental Gaussian beams can be obtained as specials cases of HhCG beams.

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