Ivan Moreno | Universidad Autónoma de Zacatecas (original) (raw)

Papers by Ivan Moreno

Research paper thumbnail of Irradiance pattern model of LED at short distances

Light-emitting diodes (LEDs) play a major role in many applications where intense light irradiati... more Light-emitting diodes (LEDs) play a major role in many applications where intense light irradiation is necessary. There are several LED radiation pattern models, which are widely used, but are valid only for far-field. In this work, we propose a mathematical model for the spatial distribution of irradiance of LEDs at near working distances.

Research paper thumbnail of Ray tracing in metasurfaces

Optics Continuum

Ray tracing in a metasurface is the process to obtain the three-dimensional (3D) light path under... more Ray tracing in a metasurface is the process to obtain the three-dimensional (3D) light path under reflection and transmission, which may be helpful in the optical design of metalenses and other metaoptical devices. In this work, first we deduce the 3D vector form of Snell's law for metasurfaces by using a geometric approach. And then, we deduce the general equations to calculate the direction of the reflected and refracted beams in any metasurface, and for any incident beam. In other words, we derive vector form equations for the 3D direction of transmitted and reflected beams at a metasurface with arbitrary 2D phase profile, and for any 3D direction of incident light.

Research paper thumbnail of Ray tracing in metasurfaces

Opt. Continuum, 2022

Ray tracing in a metasurface is the process to obtain the three-dimensional (3D) light path under... more Ray tracing in a metasurface is the process to obtain the three-dimensional (3D) light path under reflection and transmission, which may be helpful in the optical design of metalenses and other metaoptical devices. In this work, first we deduce the 3D vector form of Snell's law for metasurfaces by using a geometric approach. And then, we deduce the general equations to calculate the direction of the reflected and refracted beams in any metasurface, and for any incident beam. In other words, we derive vector form equations for the 3D direction of transmitted and reflected beams at a metasurface with arbitrary 2D phase profile, and for any 3D direction of incident light.

Research paper thumbnail of Color multifractal analysis of city lights from outer space

Latin America Optics and Photonics Conference, 2018

Research paper thumbnail of Aggregation of superparamagnetic colloids strongly confined in spherical cavities under magnetic fields

Molecular Physics, 2021

Aggregates of superparamagnetic colloids confined in liposomes in the presence of a controllable ... more Aggregates of superparamagnetic colloids confined in liposomes in the presence of a controllable external magnetic field are studied here by computer simulation. A model of a hard sphere with a central dipole has been used to simulate secondary particles of colloids confined to move within a liposome, which is modelled as a hard spherical cavity. We focus our study on the structure of aggregates created by secondary particles, which in turn are formed by superparamagnetic particles. This study was performed by using the conventional Monte Carlo simulations and the cluster-moving Monte Carlo method. The results obtained with both methods show a dependence on the number of particles and on the ratio cavity-colloid diameters. However, the usual Monte Carlo method does not allow the collective movement of the aggregates. The simulation results show, that for the particular case of the liposome diameter obtained from the experiments , the formation of a single ribbons located at the centre of the cavity for N = 30 and N = 60. In addition, we analyse the structure formation for different values of , the equilibrium structures are chains for systems for lower , whereas ribbons formation are structures of equilibrium for . GRAPHICAL ABSTRACT

Research paper thumbnail of An irradiance formula of LEDs at near zone

In this work, we deduce an exact analytical solution of irradiance produced by a Lambertian recta... more In this work, we deduce an exact analytical solution of irradiance produced by a Lambertian rectangular source at short distances, which may approximate the irradiance of a typical light-emitting diode (LED) with rectangular shape.

Research paper thumbnail of LED irradiance pattern at short distances

Applied Optics, 2019

Many emerging light-emitting diode (LED) applications require short-distance illumination. For th... more Many emerging light-emitting diode (LED) applications require short-distance illumination. For that, we derive an exact formula of the illumination profile produced by Lambertian LEDs, in which all parameters are fundamental constants. Moreover, we propose a general, simple, but accurate mathematical model of the irradiance pattern, valid for Lambertian and non-Lambertian LEDs at short distances. This model provides the irradiance profile as a function of both the LED-target distance and the coordinates of every point on the irradiated surface. The model is formulated in terms of simple sigmoid functions, in which LED size and light flux are fundamental parameters. The accuracy of the irradiance pattern model is tested both with theory and with experimental measurements.

Research paper thumbnail of Eu3+ -doped glass as a color rendering index enhancer in phosphor-in-glass

Journal of the American Ceramic Society, 2018

Research paper thumbnail of Differential sensor in front photopyroelectric technique: II. Experimental

Journal of Physics D: Applied Physics, 2009

Research paper thumbnail of Dual color tuning in Ce3+ -doped oxyfluoride ceramic phosphor plate for white LED application

Journal of the American Ceramic Society, 2018

Research paper thumbnail of High emission Intensity of green light in glass ceramic for LED's

Latin America Optics and Photonics Conference, 2016

Strong emission of green light in ceramic glass was obtained. The intensity of the emitted signal... more Strong emission of green light in ceramic glass was obtained. The intensity of the emitted signal changes with the heat treatment temperature.

Research paper thumbnail of Persistent luminescence of Eu^2+ doped glass ceramic for AC LED

Latin America Optics and Photonics Conference, 2016

Strong green-yellow emission in Eu2+ doped glass ceramic as a function of rare earth concentratio... more Strong green-yellow emission in Eu2+ doped glass ceramic as a function of rare earth concentration was obtained. Proof of concept for solid state white lighting with high power AC LED was fabricated.

Research paper thumbnail of Digital Holographic Interferometry without Phase Unwrapping by a Convolutional Neural Network for Concentration Measurements in Liquid Samples

Applied Sciences, 2020

Convolutional neural networks (CNNs) and digital holographic interferometry (DHI) can be combined... more Convolutional neural networks (CNNs) and digital holographic interferometry (DHI) can be combined to improve the calculation efficiency and to simplify the procedures of many DHI applications. In DHI, for the measurements of concentration differences between liquid samples, two or more holograms are compared to find the difference phases among them, and then to estimate the concentration values. However, liquid samples with high concentration difference values are difficult to calculate using common phase unwrapping methods as they have high spatial frequencies. In this research, a new method to skip the phase unwrapping process in DHI, based on CNNs, is proposed. For this, images acquired by Guerrero-Mendez et al. (Metrology and Measurement Systems 24, 19–26, 2017) were used to train the CNN, and a multiple linear regression algorithm was fitted to estimate the concentration values for liquid samples. In addition, new images were recorded to evaluate the performance of the proposed...

Research paper thumbnail of Multichip LED irradiance pattern model for near distance

A multichip light-emitting diode (LED) should not be treated as a point source at short-distance ... more A multichip light-emitting diode (LED) should not be treated as a point source at short-distance illumination. For that, we propose a general, simple, but accurate mathematical model of the irradiance spatial distribution for multichip LEDs, valid at very short distance illumination. This model provides the irradiance profile as a function of both the LED-target distance and the coordinates of every point on the irradiated surface. The model is formulated in function of the chip array geometry, number chips, multichip LED size, and light flux. The accuracy of the irradiance pattern model is tested both with theory and with experimental measurements.

Research paper thumbnail of Fundamentos teóricos de la optimización de la electrónica de medición para experimentos con técnicas fotopiroeléctricas

Resumen es: Al planear un experimento con la tecnica fotopiroelectrica, se deben encontrar los pa... more Resumen es: Al planear un experimento con la tecnica fotopiroelectrica, se deben encontrar los parametros adecuados del equipo de medicion para evitar la distorsion ...

Research paper thumbnail of Ronchi-Hartmann type null screens for testing a plano-freeform surface with a detection plane inside a caustic surface

Optics express, 2021

We have implemented an exact ray trace through a plano-freeform surface for an incident plane wav... more We have implemented an exact ray trace through a plano-freeform surface for an incident plane wavefront. We obtain two caustic surfaces and provide the critical points related to the ray tracing process. Additionally, we study the propagation of the refracted wavefronts through the plane-curved surface. Finally, by using the Ronchi-Hartmann type null screen and placing the detection plane within the caustic region, we have evaluated the shape of a plano-freeform optical surface under test, obtaining an RMS difference in sagitta value of 6.3 μm.

Research paper thumbnail of Effects of Colored Light on Growth and Nutritional Composition of Tilapia, and Biofloc as a Food Source

Applied Sciences, Jan 3, 2020

Research paper thumbnail of Design of LED Street Lighting Adapted for Free-Form Roads

Research paper thumbnail of Light spectrum for maximum luminous efficacy of radiation and high color quality

Current Developments in Lens Design and Optical Engineering XIX

To date, many studies on the optimization of the spectral power distributions (SPDs) have been co... more To date, many studies on the optimization of the spectral power distributions (SPDs) have been conducted to maximize the energy performance and color quality of white light-emitting diodes (LEDs). Here, not only for LEDs but for any light source, we numerically calculate the SPDs which maximize luminous efficacy of radiation (LER) in function of the color rendering index and of color temperature. As previously reported in the literature, we obtain optimal SPDs that are discrete spectra rather than continuous, but with considerably higher LER values. Such optimal SPDs may be used to design various lighting technologies: incandescent, fluorescent, high-intensity discharge, laser, and solid-state lighting.

Research paper thumbnail of Modeling the irradiation pattern of LEDs at short distances

Optics Express, 2021

A method for modeling the irradiance spatial distribution by light-emitting diodes (LEDs) on near... more A method for modeling the irradiance spatial distribution by light-emitting diodes (LEDs) on near distance targets has been developed. The model can easily handle the complex simulation of non-homogenous emitting LEDs, multichip LEDs, LED arrays, and phosphor coated LEDs. The LED irradiation profile is obtained by image processing one photograph of the emitting LED, taken with a smartphone. The method uses image convolution or image correlation between the LED image and a special kernel. The model provides the irradiation spatial pattern in function of the irradiation distance. And the model is tested both with theory and with experimental measurements.

Research paper thumbnail of Irradiance pattern model of LED at short distances

Light-emitting diodes (LEDs) play a major role in many applications where intense light irradiati... more Light-emitting diodes (LEDs) play a major role in many applications where intense light irradiation is necessary. There are several LED radiation pattern models, which are widely used, but are valid only for far-field. In this work, we propose a mathematical model for the spatial distribution of irradiance of LEDs at near working distances.

Research paper thumbnail of Ray tracing in metasurfaces

Optics Continuum

Ray tracing in a metasurface is the process to obtain the three-dimensional (3D) light path under... more Ray tracing in a metasurface is the process to obtain the three-dimensional (3D) light path under reflection and transmission, which may be helpful in the optical design of metalenses and other metaoptical devices. In this work, first we deduce the 3D vector form of Snell's law for metasurfaces by using a geometric approach. And then, we deduce the general equations to calculate the direction of the reflected and refracted beams in any metasurface, and for any incident beam. In other words, we derive vector form equations for the 3D direction of transmitted and reflected beams at a metasurface with arbitrary 2D phase profile, and for any 3D direction of incident light.

Research paper thumbnail of Ray tracing in metasurfaces

Opt. Continuum, 2022

Ray tracing in a metasurface is the process to obtain the three-dimensional (3D) light path under... more Ray tracing in a metasurface is the process to obtain the three-dimensional (3D) light path under reflection and transmission, which may be helpful in the optical design of metalenses and other metaoptical devices. In this work, first we deduce the 3D vector form of Snell's law for metasurfaces by using a geometric approach. And then, we deduce the general equations to calculate the direction of the reflected and refracted beams in any metasurface, and for any incident beam. In other words, we derive vector form equations for the 3D direction of transmitted and reflected beams at a metasurface with arbitrary 2D phase profile, and for any 3D direction of incident light.

Research paper thumbnail of Color multifractal analysis of city lights from outer space

Latin America Optics and Photonics Conference, 2018

Research paper thumbnail of Aggregation of superparamagnetic colloids strongly confined in spherical cavities under magnetic fields

Molecular Physics, 2021

Aggregates of superparamagnetic colloids confined in liposomes in the presence of a controllable ... more Aggregates of superparamagnetic colloids confined in liposomes in the presence of a controllable external magnetic field are studied here by computer simulation. A model of a hard sphere with a central dipole has been used to simulate secondary particles of colloids confined to move within a liposome, which is modelled as a hard spherical cavity. We focus our study on the structure of aggregates created by secondary particles, which in turn are formed by superparamagnetic particles. This study was performed by using the conventional Monte Carlo simulations and the cluster-moving Monte Carlo method. The results obtained with both methods show a dependence on the number of particles and on the ratio cavity-colloid diameters. However, the usual Monte Carlo method does not allow the collective movement of the aggregates. The simulation results show, that for the particular case of the liposome diameter obtained from the experiments , the formation of a single ribbons located at the centre of the cavity for N = 30 and N = 60. In addition, we analyse the structure formation for different values of , the equilibrium structures are chains for systems for lower , whereas ribbons formation are structures of equilibrium for . GRAPHICAL ABSTRACT

Research paper thumbnail of An irradiance formula of LEDs at near zone

In this work, we deduce an exact analytical solution of irradiance produced by a Lambertian recta... more In this work, we deduce an exact analytical solution of irradiance produced by a Lambertian rectangular source at short distances, which may approximate the irradiance of a typical light-emitting diode (LED) with rectangular shape.

Research paper thumbnail of LED irradiance pattern at short distances

Applied Optics, 2019

Many emerging light-emitting diode (LED) applications require short-distance illumination. For th... more Many emerging light-emitting diode (LED) applications require short-distance illumination. For that, we derive an exact formula of the illumination profile produced by Lambertian LEDs, in which all parameters are fundamental constants. Moreover, we propose a general, simple, but accurate mathematical model of the irradiance pattern, valid for Lambertian and non-Lambertian LEDs at short distances. This model provides the irradiance profile as a function of both the LED-target distance and the coordinates of every point on the irradiated surface. The model is formulated in terms of simple sigmoid functions, in which LED size and light flux are fundamental parameters. The accuracy of the irradiance pattern model is tested both with theory and with experimental measurements.

Research paper thumbnail of Eu3+ -doped glass as a color rendering index enhancer in phosphor-in-glass

Journal of the American Ceramic Society, 2018

Research paper thumbnail of Differential sensor in front photopyroelectric technique: II. Experimental

Journal of Physics D: Applied Physics, 2009

Research paper thumbnail of Dual color tuning in Ce3+ -doped oxyfluoride ceramic phosphor plate for white LED application

Journal of the American Ceramic Society, 2018

Research paper thumbnail of High emission Intensity of green light in glass ceramic for LED's

Latin America Optics and Photonics Conference, 2016

Strong emission of green light in ceramic glass was obtained. The intensity of the emitted signal... more Strong emission of green light in ceramic glass was obtained. The intensity of the emitted signal changes with the heat treatment temperature.

Research paper thumbnail of Persistent luminescence of Eu^2+ doped glass ceramic for AC LED

Latin America Optics and Photonics Conference, 2016

Strong green-yellow emission in Eu2+ doped glass ceramic as a function of rare earth concentratio... more Strong green-yellow emission in Eu2+ doped glass ceramic as a function of rare earth concentration was obtained. Proof of concept for solid state white lighting with high power AC LED was fabricated.

Research paper thumbnail of Digital Holographic Interferometry without Phase Unwrapping by a Convolutional Neural Network for Concentration Measurements in Liquid Samples

Applied Sciences, 2020

Convolutional neural networks (CNNs) and digital holographic interferometry (DHI) can be combined... more Convolutional neural networks (CNNs) and digital holographic interferometry (DHI) can be combined to improve the calculation efficiency and to simplify the procedures of many DHI applications. In DHI, for the measurements of concentration differences between liquid samples, two or more holograms are compared to find the difference phases among them, and then to estimate the concentration values. However, liquid samples with high concentration difference values are difficult to calculate using common phase unwrapping methods as they have high spatial frequencies. In this research, a new method to skip the phase unwrapping process in DHI, based on CNNs, is proposed. For this, images acquired by Guerrero-Mendez et al. (Metrology and Measurement Systems 24, 19–26, 2017) were used to train the CNN, and a multiple linear regression algorithm was fitted to estimate the concentration values for liquid samples. In addition, new images were recorded to evaluate the performance of the proposed...

Research paper thumbnail of Multichip LED irradiance pattern model for near distance

A multichip light-emitting diode (LED) should not be treated as a point source at short-distance ... more A multichip light-emitting diode (LED) should not be treated as a point source at short-distance illumination. For that, we propose a general, simple, but accurate mathematical model of the irradiance spatial distribution for multichip LEDs, valid at very short distance illumination. This model provides the irradiance profile as a function of both the LED-target distance and the coordinates of every point on the irradiated surface. The model is formulated in function of the chip array geometry, number chips, multichip LED size, and light flux. The accuracy of the irradiance pattern model is tested both with theory and with experimental measurements.

Research paper thumbnail of Fundamentos teóricos de la optimización de la electrónica de medición para experimentos con técnicas fotopiroeléctricas

Resumen es: Al planear un experimento con la tecnica fotopiroelectrica, se deben encontrar los pa... more Resumen es: Al planear un experimento con la tecnica fotopiroelectrica, se deben encontrar los parametros adecuados del equipo de medicion para evitar la distorsion ...

Research paper thumbnail of Ronchi-Hartmann type null screens for testing a plano-freeform surface with a detection plane inside a caustic surface

Optics express, 2021

We have implemented an exact ray trace through a plano-freeform surface for an incident plane wav... more We have implemented an exact ray trace through a plano-freeform surface for an incident plane wavefront. We obtain two caustic surfaces and provide the critical points related to the ray tracing process. Additionally, we study the propagation of the refracted wavefronts through the plane-curved surface. Finally, by using the Ronchi-Hartmann type null screen and placing the detection plane within the caustic region, we have evaluated the shape of a plano-freeform optical surface under test, obtaining an RMS difference in sagitta value of 6.3 μm.

Research paper thumbnail of Effects of Colored Light on Growth and Nutritional Composition of Tilapia, and Biofloc as a Food Source

Applied Sciences, Jan 3, 2020

Research paper thumbnail of Design of LED Street Lighting Adapted for Free-Form Roads

Research paper thumbnail of Light spectrum for maximum luminous efficacy of radiation and high color quality

Current Developments in Lens Design and Optical Engineering XIX

To date, many studies on the optimization of the spectral power distributions (SPDs) have been co... more To date, many studies on the optimization of the spectral power distributions (SPDs) have been conducted to maximize the energy performance and color quality of white light-emitting diodes (LEDs). Here, not only for LEDs but for any light source, we numerically calculate the SPDs which maximize luminous efficacy of radiation (LER) in function of the color rendering index and of color temperature. As previously reported in the literature, we obtain optimal SPDs that are discrete spectra rather than continuous, but with considerably higher LER values. Such optimal SPDs may be used to design various lighting technologies: incandescent, fluorescent, high-intensity discharge, laser, and solid-state lighting.

Research paper thumbnail of Modeling the irradiation pattern of LEDs at short distances

Optics Express, 2021

A method for modeling the irradiance spatial distribution by light-emitting diodes (LEDs) on near... more A method for modeling the irradiance spatial distribution by light-emitting diodes (LEDs) on near distance targets has been developed. The model can easily handle the complex simulation of non-homogenous emitting LEDs, multichip LEDs, LED arrays, and phosphor coated LEDs. The LED irradiation profile is obtained by image processing one photograph of the emitting LED, taken with a smartphone. The method uses image convolution or image correlation between the LED image and a special kernel. The model provides the irradiation spatial pattern in function of the irradiation distance. And the model is tested both with theory and with experimental measurements.