Journal ArticleDOI
Focal shift effects in diffracted focused beams
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TLDR
In this article, the authors studied the propagation characteristics of focused, apertured radially symmetric beams and showed that the axial point at which the mean-square radius of the diffracted beam is a minimum tends to be displaced towards the aperture plane depending on the Fresnel number associated with the aperture and the radius of an incident beam.Abstract:
We study the propagation characteristics of focused, apertured radially symmetric beams and show that the axial point at which the mean-square radius of the diffracted beam is a minimum tends to be displaced towards the aperture plane depending on the Fresnel number associated with the aperture and the Fresnel number associated with the radius of the incident beam. The magnitude of this effect can be determined by a simple and general formula in terms of the amplitude distribution of the incident beam across the aperture and of the two Fresnel numbers. We investigate the focal shift effects for the case of a focused, apertured Gaussian beam. The irradiance and the encircled-power distributions in the plane at which the mean-square radius of the diffracted beam is minimum are calculated and compared with those corresponding to a uniform beam.read more
Citations
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Journal ArticleDOI
Focal shift, optical transfer function, and phase-space representations
TL;DR: The focal shift for a lens of finite value of Fresnel number can be defined in terms of the second moment of the intensity distribution in transverse planes and the uncertainty principle is discussed, including the significance of the beam propagation factor M2 and the width of optical fiber beam modes.
Journal ArticleDOI
Experimental and numerical analyses of misalignment tolerances in free-space optical interconnects.
TL;DR: A comparison of numerical analyses with experimental measurements suggests that both the ray-tracing and the Gaussian beam-propagation models overestimate the misalignment tolerances for on- axis beams and fail to predict the large longitudinal focal shift that occurs for off-axis beams propagating in free-space optical interconnects.
Journal ArticleDOI
Focal-shift formula in apodized nontelecentric focusing systems
TL;DR: A single analytical formulation for evaluating the focal shift in any apodized nontelecentric focusing setup is reported and it is shown explicitly that the magnitude of the focalshift is determined by only one parameter that depends on the effective width of the pupil filter and its axial position.
Journal ArticleDOI
Spot size and radial intensity distribution of focused Gaussian beams in spherical and non-spherical aberration lenses
TL;DR: In this article, the radial intensity distribution in the presence of spherical aberrations (SA) for cases in which the incident field is a focused Gaussian spot was discussed. And a numerical solution of a two dimensional integral diffraction (paraxial ray) equation for a relatively large SA was developed by using the well-known trapezoidal rule for integration.
Journal ArticleDOI
Z-scan sensitivity enhancement using a binary diffractive optics
TL;DR: In this article, a phase aperture made from a transparent plate that has a circular relief introducing a π phase shift in the central region of the incident beam was used to enhance the sensitivity of Z-scan.
References
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Book
Linear systems, Fourier transforms, and optics
TL;DR: This book describes the representation of Physical Quantities by Mathematical Functions and the applications of Linear Filters and Two-Dimensional Convolution and Fourier Transformation.
Journal ArticleDOI
Imaging of optical modes — resonators with internal lenses
TL;DR: In this paper, the modes of optical resonators, and optical modes of propagation or Gaussian beams of light are discussed, and a complex beam parameter is introduced for which the law of transformation by any given optical structure can be written in the simple form of a bilinear transformation.
Journal ArticleDOI
Focal shifts in diffracted converging spherical waves
TL;DR: In this paper, it was shown that when the incident wave is uniform and the angular semi-aperture is small, the ratio of the point of maximum intensity to the distance between the geometrical focus and the plane of the aperture depends only on the Fresnel number N of the image when viewed from the focal point.
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Focal shift in focused truncated gaussian beams
TL;DR: In this paper, the point of maximum intensity in a focused aberration-free wave is not at the geometrical focus, but is closer to the focusing lens, where the waist of the beam is assumed to be located in the aperture plane.
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Uniform versus Gaussian beams: a comparison of the effects of diffraction, obscuration, and aberrations
TL;DR: In this paper, the axial irradiance of focused uniform and Gaussian beams is calculated and the problem of optimum focusing is discussed, and the results for a collimated beam are obtained as a limiting case of a focused beam.