Quiroga Mellado, Juan Antonio

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First Name
Juan Antonio
Last Name
Quiroga Mellado
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Físicas
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Now showing 1 - 10 of 34
  • Publication
    Noise in phase shifting interferometry
    (The Optical Society Of America, 2009-05-25) Quiroga Mellado, Juan Antonio; Estrada, Julio César; Servín Guirado, Manuel; Mosiño, Juan Francisco; Cywiak Garbarcewics, Moisés
    We present a theoretical analysis to estimate the amount of phase noise due to noisy interferograms in Phase Shifting Interferometry (PSI). We also analyze the fact that linear filtering transforms corrupting multiplicative noise in Electronic Speckle Pattern Interferometry (ESPI) into fringes corrupted by additive gaussian noise. This fact allow us to obtain a formula to estimate the standard deviation of the noisy demodulated phase as a function of the spectral response of the preprocessing spatial filtering combined with the PSI algorithm used. This phase noise power formula is the main result of this contribution.
  • Publication
    Improved regularised phase-tracking technique for the processing of squared-grating deflectograms
    (The Optical Society of America, 2000-02-01) Quiroga Mellado, Juan Antonio; Villa Hernández, José de Jesús; Servín Guirado, Manuel
    We propose a robust procedure based on the regularized phase-tracking (RPT) technique to demodulate squared-grating deflectograms. The use of squared gratings, already reported, lets us multiplex the information of the deflections in two orthogonal directions in a single image, thus avoiding the necessity of rotating the gratings. The good noise-rejection characteristics of the RPT technique are improved by use of a quasi-Newton optimization algorithm and a quality-map-based algorithm for the crystal-growing process.
  • Publication
    Spectral analysis of phase shifting algorithms
    (The Optical Society Of America, 2009-09-14) Quiroga Mellado, Juan Antonio; Estrada, Julio César; Servín Guirado, Manuel
    Systematic spectral analysis of Phase Shifting Interferometry (PSI) algorithms was first proposed in 1990 by Freischlad and Koliopoulos (F&K). This analysis was proposed with the intention that "in a glance" the main properties of the PSI algorithms would be highlighted. However a major drawback of the F&K spectral analysis is that it changes when the PSI algorithm is rotated or its reference signal is time-shifted. In other words, the F&K spectral plot is different when the PSI algorithm is rotated or its reference is time-shifted. However, it is well known that these simple operations do not alter the basic phase demodulation properties of PSI algorithms, except for an unimportant piston. Here we propose a new way to analyze the spectra of PSI algorithms which is invariant to rotation and/or reference time-shift among other advantages over the nowadays standard PSI spectral analysis by F&K.
  • Publication
    The general theory of phase shifting algorithms
    (The Optical Society Of America, 2009-11-23) Quiroga Mellado, Juan Antonio; Estrada, Julio César; Servín Guirado, Manuel
    We have been reporting several new techniques of analysis and synthesis applied to Phase Shifting Interferometry (PSI). These works are based upon the Frequency Transfer Function (FTF) and how this new tool of analysis and synthesis in PSI may be applied to obtain very general results, among them; rotational invariant spectrum; complex PSI algorithms synthesis based on simpler first and second order quadrature filters; more accurate formulae for estimating the detuning error; output-power phase noise estimation. We have made our cases exposing these aspects of PSI separately. Now in the light of a better understanding provided by our past works we present and expand in a more coherent and holistic way the general theory of PSI algorithms. We are also providing herein new material not reported before. These new results are on; a well defined way to combine PSI algorithms and recursive linear PSI algorithms to obtain resonant quadrature filters.
  • Publication
    A isotropic n-dimensional quadrature transform and its applications in fringe pattern processing
    (SPIE--The International Society for Optical Engineering, 2003) Quiroga Mellado, Juan Antonio; Servín Guirado, Manuel; Marroquín Zaleta, José Luis; Gómez Pedrero, José Antonio
    In fringe pattern processing, quadrature operators are useful to obtain the corresponding modulating phase. In the case that a carrier exists (spatial or temporal), there are good methods for phase demodulation as Fourier analysis and asynchronous methods, for example. However, if there is no carrier or is to low, robust demodulation from a single image is a difficult task. In this work we present some recent advances in the processing of single fringe patterns with closed fringes based in a isotropic n-dimensional quadrature transform. In particular we address several problems related with the application of this quadrature operator. One of these problems is the Fringe direction, its role in the demodulation process is discussed and a practical method for its computation is presented. Fringe pattern normalization is also an important subject in the demodulation process from a singe image, taking this into account we present a technique for isotropic fringe pattern normalization based in the n-dimensional quadrature transform. All these techniques together configure a robust method for automatic demodulation of single fringe patterns. The performance and limitations of the method are discussed and illustrated by experimental results.
  • Publication
    Steerable spatial phase shifting applied to single-image closed-fringe interferograms
    (The Optical Society of America, 2009-04-20) Quiroga Mellado, Juan Antonio; Servín Guirado, Manuel; Estrada, Julio César; Gómez Pedrero, José Antonio
    It is well known that spatial phase shifting interferometry (SPSI) may be used to demodulate two-dimensional (2D) spatial-carrier-interfrograms. In these crises the application of SPSI is straightforward because the modulating phase is a monotonic increasing function of space. However, this is not true when we apply SPSI to demodulate a single-image interferogram containing closed fringes. This is because using these algorithms, one would obtain a wrongly demodulated monotonic phase all over the 2D space. We present a technique to overcome this drawback and to allow any SPSI algorithm to be used as a single-image fringe pattern demodulator containing closed fringes. We make use of the 2D spatial orientation direction of the fringes to steer (orient) the one-dimensional SPSI algorithm in order to correctly demodulate the nonmonotonic 2D phase all over the interferogram.
  • Publication
    Isotropic n-dimensional fringe pattern normalization
    (Elsevier Science BV, 2003-09-01) Quiroga Mellado, Juan Antonio; Servín Guirado, Manuel
    Fringe pattern normalization consists in the background suppression and modulation normalization of a given fringe pattern, this process gives as a result a pure sinusoidal phase modulated signal. Normalization is an important operation in the demodulation of the phase from a single fringe pattern where spatially varying background and/or modulation act as error sources. The solution proposed is a direct and isotropic operator, based on the application of an n-dimensional quadrature transform. We have applied the method to simulated as well as experimental data with good results.
  • Publication
    Easy and straightforward construction of wideband phase-shifting algorithms for interferometry
    (The Optical Society of America, 2009-02-15) Quiroga Mellado, Juan Antonio; Servín Guirado, Manuel; Estrada, Julio César
    We show a practical way for building wideband phase-shifting algorithms for interferometry. The idea presented combines first- and second-order quadrature filters to obtain wideband phase-shifting algorithms. These first- and second-order quadrature filters are analogous to the first- and second-order filters commonly used in communications engineering, named building blocks. We present a systematic way to develop phase-shifting algorithms with large detuning robustness or large bandwidth. In general, the approach presented here gives a powerful frequency analysis and design tool for phase-shifting algorithms robust to detuning for interferometry.
  • Publication
    Role of the filter phase in phase sampling interferometry
    (The Optical Society Of America, 2011-10-10) Quiroga Mellado, Juan Antonio; Servín Guirado, Manuel; Estrada, Julio César; Vargas Balbuena, Javier; Torre Belizón, Francisco Javier de la
    Any linear phase sampling algorithm can be described as a linear filter characterized by its frequency response. In traditional phase sampling interferometry the phase of the frequency response has been ignored because the impulse responses can be made real selecting the correct sample offset. However least squares methods and recursive filters can have a complex frequency response. In this paper, we derive the quadrature equations for a general phase sampling algorithm and describe the role of the filter phase.
  • Publication
    Temporal demodulation of fringe patterns with sensitivity change
    (Elsevier Science BV, 2005-09-15) Quiroga Mellado, Juan Antonio; Gómez Pedrero, José Antonio; Terrón López, M. José; Servín Guirado, Manuel
    There are many phase measuring experimental setups in which the rate of temporal phase variation cannot be easily determined. In the case of phase stepping techniques, asynchronous phase measuring techniques were developed to solve this problem. However, there are situations for which the standard asynchronous techniques are not appropriated, like experiments with a sensitivity variation in the phase. In this work, we present an asynchronous demodulation technique for which the only requirement is the monotonicity of the phase in time. The proposed method is based in the computation of the quadrature sign (QS) of the fringe pattern and afterwards the demodulation is performed by a simple arccos calculation, that thanks to the QS extends its range from half fringe to a modulo 2π calculation. The presented demodulation method is asynchronous, direct, fast and can be applied to a general n-dimensional case. We have applied the proposed method to a load stepping experimental fringe pattern obtaining good results.