Author
Maria Victoria Perez
Other affiliations: Universidad Miguel Hernández de Elche
Bio: Maria Victoria Perez is an academic researcher from University of Santiago de Compostela. The author has contributed to research in topics: Talbot effect & Lens (optics). The author has an hindex of 13, co-authored 58 publications receiving 633 citations. Previous affiliations of Maria Victoria Perez include Universidad Miguel Hernández de Elche.
Papers published on a yearly basis
Papers
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Book•
01 Jan 2002
TL;DR: In this paper, the authors present a model of a GRIN lens for uniform illumination in an active GRIN medium, where the kernel function is modelled as a vector wave.
Abstract: 1 Light Propagation in GRIN Media.- 1.1 Introduction.- 1.2 Vector Wave Equations.- 1.3 Scalar Wave Equation.- 1.4 Parabolic Wave Equation.- 1.5 Ray Optics: Axial and Field Rays.- 2 Imaging and Transforming Transmission Through GRIN Media.- 2.1 Introduction.- 2.2 The Kernel Function.- 2.3 Imaging and Fourier Transforming Through GRIN Media.- 2.4 Fractional Fourier Transforming in GRIN Media.- 2.5 Modal Representation of the Kernel.- 3 GRIN Lenses for Uniform Illumination.- 3.1 Introduction.- 3.2 Transmittance Function of a GRIN Lens for Uniform Illumination.- 3.3 GRIN Lens Law: Imaging and Fourier Transforming by GRIN Lens.- 3.4 Geometrical Optics of GRIN Lenses.- 3.5 Effective Radius, Numerical Aperture, Aperture Stop, and Pupils.- 3.6 Diffraction-Limited Propagation of Light in a GRIN lens.- 3.7 Effect of the Aperture on Image and Fourier Transform Formation.- 4 GRIN Lenses for Gaussian Illumination.- 4.1 Introduction.- 4.2 Propagation of Gaussian Beams in a GRIN Lens.- 4.3 GRIN Lens Law: Image and Focal Shifts.- 4.4 Effective Aperture.- 5 GRIN Media with Loss or Gain.- 5.1 Introduction.- 5.2 Active GRIN Materials: Complex Refractive Index.- 5.3 The Kernel Function.- 5.4 Focal Distance and Focal Shift for Uniform Illumination.- 5.5 Gaussian Illumination in an Active GRIN Medium: Beam Parameters.- 5.6 Transformation of a Gaussian Beam into a Uniform Beam.- 6 Planar GRIN Media with Hyperbolic Secant Refractive Index Profile.- 6.1 Introduction.- 6.2 Ray Equation and ABCD Law.- 6.3 Focusing and Collimation Properties.- 6.4 Numerical Aperture: On-Axis and Off-Axis Coupling.- 6.5 Mode Propagation.- 6.6 The Kernel Function.- 6.7 Diffraction-Free and Diffraction-Limited Propagation of Light.- 7 The Talbot Effect in GRIN Media.- 7.1 Introduction.- 7.2 Light Propagation and Imaging Condition.- 7.3 The Integer Talbot Effect.- 7.4 Self-Image Distances.- 7.5 Fractional Talbot Effect: Unit Cell.- 7.6 Effect of Off-Axis Source and Finite Object Dimension on Self-Images.- 8 GRIN Crystalline Lens.- 8.1 Introduction.- 8.2 The Optical Structure of the Human Eye.- 8.3 The GRIN Model of the Crystalline Lens.- 8.4 The Gradient Parameter: Axial and Field Rays in the Crystalline Lens.- 8.5 Refractive Power and Cardinal Points of the Crystalline Lens.- 9 Optical Connections by GRIN Lenses.- 9.1 Introduction.- 9.2 GRIN Fiber Lens.- 9.3 Anamorphic Selfoc Lens.- 9.4 Tapered GRIN Lens.- 9.5 Selfoc Lens.- References.
143 citations
TL;DR: In this paper, the Fraunhofer and Fresnel diffraction patterns produced by a thin linear axicon when it is illuminated by a plane wavefront were determined, and an interferometric method of recording zone plates using linear axicons was presented.
Abstract: We determine the Fraunhofer and Fresnel diffraction patterns produced by a thin linear axicon when it is illuminated by a plane wavefront. An interferometric method of recording zone plates using linear axicons is presented.
70 citations
TL;DR: In this article, the design of crossover and parallel interconnects by using a GRIN planar structure is presented. But the authors focus on the coupling efficiency as well as the coupling loss versus variation of the GRIN fiber lens length and the refractive-index profile of the coupler.
Abstract: This paper reviews the design of some optical systems for coupling and interconnection by GRIN components. The optical systems designed with these components are based on imaging and transforming properties of such components to carry out specific functions. First of all, a brief description of light propagation through GRIN materials will be given. After that, a device to couple light by a GRIN fiber lens into fibers of different core sizes with low loss is described. The coupling efficiency as well as the coupling loss are studied versus variation of the GRIN fiber lens length and the refractive-index profile of the coupler. The design of crossover and parallel interconnects by using a GRIN planar structure will be presented. The optical analysis includes the PSF for describing the performance of the device and the SBP for estimating the numbers of channels that can be handled. The dependence of the number of channels on the wavelength of light and the transverse aperture of the planar interconnect is shown.
49 citations
TL;DR: Under stable atmospheric conditions, the brightness of the urban sky varies throughout the night following the time course of the anthropogenic emissions of light as mentioned in this paper, and different types of artificial light sources are used.
Abstract: Under stable atmospheric conditions the brightness of the urban sky varies throughout the night following the time course of the anthropogenic emissions of light. Different types of artificial ligh...
37 citations
TL;DR: In this paper, a study of the stochastic description of the Talbot effect in the temporal domain under random timing jitter is presented, and it is shown that this smoothing effect also occurs in Talbot devices leading to N× repetition rates of the original train.
Abstract: A study of the stochastic description of the Talbot effect in the temporal domain under random timing jitter is presented. The relevant statistical quantity is the variance. The variance of a train of pulses, each one affected by random timing jitter, shows peaks in the edges of the pulses. When this train is Talbot-imaged, the variance becomes flattened along the unit interval corresponding to each pulse as a result of the dispersion of the individual pulses of the train. Fractional Talbot devices are also analyzed. In particular, it is shown that this smoothing effect also occurs in Talbot devices leading to N× repetition rates of the original train.
34 citations
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TL;DR: This work shows by the method of stationary phase that any of these wave fields can be realized approximately with a laser and a single computer-generated hologram, and demonstrates experimentally the formation of arbitrary-order Bessel beams and rotationally nonsymmetric beams.
Abstract: A new class of solutions to the scalar wave equation was introduced recently that represents transversely localized but totally nondiffracting fields. We show by the method of stationary phase that any of these wave fields can be realized approximately with a laser and a single computer-generated hologram. We briefly discuss various techniques for coding and fabrication of the required hologram and the associated diffraction efficiencies. Using both binary-amplitude and four-level phase holograms, we demonstrate experimentally the formation of arbitrary-order Bessel beams and rotationally nonsymmetric beams.
668 citations
TL;DR: In this article, the authors proposed to obtain intense optical fields, whose form shows little change in size over long paths, through the use of either conical lenses or spherical lenses showing spherical aberration together with a single projecting lens.
Abstract: It is proposed to obtain intense optical fields, whose form shows little change in size over long paths, through the use of either conical lenses or spherical lenses showing spherical aberration together with a single projecting lens. The conical lens is shown to produce fields whose transverse structure is given by a zero-order Bessel function J0, while the spherical aberrating lens produces (real or virtual) J0-like transverse structures, provided that the central portion of the aberrating lens is occluded. In all cases projection gives a J0 real-image optical structure. Intensity, size of the transverse structure, and range considerations are developed, and some aspects of optimization are discussed. A negative aberrating lens gives a long range of nearly constant size in the image field, and a universal expression is presented to describe the image size as a function of image distance for this case. Projection with an aberrating projection lens is shown to improve the constancy of the final J0 pattern size dramatically. Typical photographic results are included for beams generated by using a low-power He–Ne laser. Brief considerations of practical uses of diffractionless beams are presented.
550 citations
TL;DR: The resolution of conventional optical lens systems is always hampered by the diffraction limit, but recent developments in artificial metamaterials provide new avenues to build hyperlenses and metalenses that are able to image beyond the diffracted limit.
Abstract: The resolution of conventional optical lens systems is always hampered by the diffraction limit. Recent developments in artificial metamaterials provide new avenues to build hyperlenses and metalenses that are able to image beyond the diffraction limit. Hyperlenses project super-resolution information to the far field through a magnification mechanism, whereas metalenses not only super-resolve subwavelength details but also enable optical Fourier transforms. Recently, there have been numerous designs for hyperlenses and metalenses, bringing fresh theoretical and experimental advances, though future directions and challenges remain to be overcome.
511 citations
TL;DR: A review of recent developments on entanglement and nonclassical effects in collective two-atom systems and a uniform physical picture of the many predicted phenomena can be found in this article.
404 citations
TL;DR: Two forms of minimally invasive fluorescence microendoscopy are developed and tested their abilities to image cells in vivo and will help meet the growing demand for in vivo cellular imaging created by the rapid emergence of new synthetic and genetically encoded fluorophores.
Abstract: One of the major limitations in the current set of techniques available to neuroscientists is a dearth of methods for imaging individual cells deep within the brains of live animals. To overcome this limitation, we developed two forms of minimally invasive fluorescence microendoscopy and tested their abilities to image cells in vivo. Both one- and two-photon fluorescence microendoscopy are based on compound gradient refractive index (GRIN) lenses that are 350–1,000 μm in diameter and provide micron-scale resolution. One-photon microendoscopy allows full-frame images to be viewed by eye or with a camera, and is well suited to fast frame-rate imaging. Two-photon microendoscopy is a laser-scanning modality that provides optical sectioning deep within tissue. Using in vivo microendoscopy we acquired video-rate movies of thalamic and CA1 hippocampal red blood cell dynamics and still-frame images of CA1 neurons and dendrites in anesthetized rats and mice. Microendoscopy will help meet the growing demand for in vivo cellular imaging created by the rapid emergence of new synthetic and genetically encoded fluorophores that can be used to label specific brain areas or cell classes.
385 citations