Carlos Gómez-Reino

Diffraction Patterns and Zone Plates Produced by Thin Linear Axicons

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 l...

Optical path integrals in gradient-index media

A path integral has been used to evaluate, in paraxial approximation, the complex amplitude transmitted through gradient-index media. This formulation is useful for examining propagation in gradient-index media.

Paraxial imaging and transforming in a medium with gradient-index: transmittance function.

In this paper we study the paraxial imaging and transforming in a medium with gradient index obtaining the image and transform conditions. The medium is characterized by a transmittance function at the output plane similar to a thin lens. This medium can be an element of imaging and optical data processing systems.

Timing jitter smoothing by Talbot effect. I. Variance

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.

Laser direct-write technique for fabricating microlens arrays on soda-lime glass with a Nd:YVO4 laser.

A one-step direct-write technique for fabricating spherical microlenses on soda-lime glass substrates is described. Using a Q switched Nd:YVO(4) laser combined with a galvanometer system, square and triangular microlens arrays were fabricated. The focal length of microlenses is measured using direct and nondirect methods. Values around 118 and 125 µm were obtained for the microlens focal length of square and triangular arrays, respectively. A noncontact profilometer is used for determining the surface roughness of square and triangular arrays. Results are compared with that of glass substrate.

Arbitrary single-mode coupling by tapered and nontapered grin fiber lenses.

Arbitrary modal field coupling is analyzed and optimized by using tapered and nontapered GRIN fiber lenses as single-mode optical fiber connectors. Conditions for achieving maximum coupling efficiency are derived.

Imaging and transforming transmission through inhomogeneous media with revolution symmetry

Abstract We study the paraxial imaging and transforming transmission through an inhomogeneous medium with spatial revolution symmetry obtaining the image and transform conditions. The medium is characterized by a transmittance function at the output plane similar to the conventional lens transmittance function.

Generalized formulation and symmetry properties of reciprocal nonabsorbing polarization devices: application to liquid-crystal displays

We present a general formulation based on the Jones-matrix theory for reciprocal nonabsorbing polarization devices, including polarization interference filters and liquid-crystal displays. The development of this formulation is based on general symmetry conditions that relate the Jones matrix when the device is illuminated from the front side and from the back side. The application to liquid-crystal displays results in a constraint of the Jones-matrix elements, which represents a generalization of the existing models that explain their modulation properties.

Paraxial Fourier transforming and imaging properties of a GRIN lens with revolution symmetry: GRIN lens law

Wave description and ray matrix methods have been used to study the paraxial Fourier transforming and imaging properties of GRIN lenses with revolution symmetry. Using these properties, the GRIN lens law and the Fourier transforming condition are derived for a simple optical system.

Transmittance function and modal propagation in a conical gradient-index rod.

In this paper we determine the image planes and the transmittance function for a conical gradient-index (GRIN) rod, and we consider the problem of modal propagation.