Free-space laser optical link simulation software

GDAF (Displays and Photonics Applications Group) in Electronics Technology Department at University Carlos III de Madrid develops a hardware-software application for a communications free-space optical link, in a Project with INSA corp. It aims to substitute the usual radio frequencies link, because of the increasing of bandwidth and the guarantee of privacity. Optics and electronics collaboration is searched

Software de simulación de un enlace óptico de comunicaciones por láser

El Grupo de Displays y Aplicaciones Fotónicas (GDAF) del Departamento de Tecnología Electrónica de la Universidad Carlos III de Madrid desarrolla una aplicación software - hardware para un enlace óptico de comunicaciones en espacio profundo, en un Proyecto con la empresa INSA (Ingeniería y Servicios Aeroespaciales S.A.). Pretende sustituir a los tradicionales enlaces por radiofrecuencia, pues aumenta el ancho de banda y garantiza la privacidad. Se busca colaboración en óptica y electrónica

Characterization and applications of New Electrochromic and Suspended Particle Devices

GDAF (Displays and Photonics Applications Group) in Electronics Technology Department at University Carlos III de Madrid research on electrochromic and suspended particle devices. It offers the characterization, the search for applications and design and implementation of optimized electronic control systems. These devices are used in smart windows and mirrors, optical communications, ophthalmic filters, etc. The advantages are mainly the power consumption and easiness of switching. Sepecific advantages arise in each application. Companies or institutions are searched that develop these devices, in order to establish collaboration about characterizations and control systems optimization

Caracterización y aplicaciones de Nuevos dispositivos Electrocrómicos y de partículas suspendidas

El Grupo de Displays y Aplicaciones Fotónicas (GDAF) del Departamento de Tecnología Electrónica de la Universidad Carlos III de Madrid investiga en dispositivos de material electrocrómico y de partículas suspendidas. Ofrece la caracterización de los mismos, la búsqueda de aplicaciones y el diseño e implementación de sistemas electrónicos de control optimizado. El uso de estos dispositivos se produce en ventanas inteligentes, espejos, comunicaciones ópticas, filtros oftalmológicos, etc. Las ventajas de estos dispositivos son el consumo y la facilidad de conmutación. Ventajas específicas surgen de las diferentes aplicaciones. Se buscan empresas o instituciones que desarrollen este tipo de dispositivos para colaborar en su caracterización y optimizar los sistemas de control

A low-cost LED-Based solar simulator

Solar simulators are a fundamental instrument to characterize solar cells parameters, as they can reproduce the operating conditions under which the solar cells are going to work. However, these systems are frequently big, heavy, and expensive, and a small solar simulator could be a good contribution to test small prototyping devices manufactured in research labs, especially if it could manage the irradiation at any wavelength interval in a custom way. We have designed, developed, and calibrated a small solar simulator made entirely with LEDs, no optics inside, and electronically controlled through a PC using an Arduino microcontroller. The whole structure is 3-D printed in black PLA plastic. The electrical current through the LEDs, and thus the spectral irradiance of the simulator, is controlled with a very intuitive LabVIEW interface. As our calibration proves, we have built an easily reproducible and low-cost Class AAA solar simulator in a central illumination area of 1 cm 2 , according to the IEC60904-9 standard. This means that the homogeneity in that area is under a 2% deviation in spatial terms, below 0.5% in temporal terms, and is a factor of a 3% close to the AM1.5G sun reference spectrum. The system can be built and used in any research lab to get quick tests of new small solar cells of any material.This work was supported in part by the Spanish Ministerio de Economía y Competitividad through AEI/FEDER, UE Funds under Grant TEC2016-77242-C3-1-R and in part by the Comunidad de Madrid SINFOTON-CM Research Program under Grant S2013/MIT-2790. The work of E. López-Fraguas was supported by the Ministerio de Educación y Formación Profesional for his Doctoral Grant through FPU Research Fellowship under Grant FPU17/00612

Electrical analysis of new all-plastic electrochromic devices

New all-plastic electrochromic devices have been manufactured using commercial PEDOT foils and classical polymer electrolyte electrodeposition techniques. Several devices with different areas have been electrically characterized by using an impedance spectroscopy technique. After a brief description of the manufacturing process, we discuss electrical properties with the size of the device. Real and imaginary parts of the impedance have been plotted as a function of frequency. Some interesting conclusions have been derived from those plots, and some improvements in manufacturing process of this kind of devices are also proposed.Publicad

In-axis reception by polarization discrimination in a modulating-retroreflector-based free-space optical communication link

A new optical configuration is proposed for ground stations designed to receive information from modulating-retroreflector-based terminals in a free-space optical communication link. This configuration is based on the polarization discrimination of the ground station laser sent to the remote terminal. It achieves the optimal usage of the laser power, which is a key parameter in modulating-retroreflector-based links. A simulation has been made in order to model the system in terms of power losses and states of polarization and an experimental setup has been implemented to verify the validity of the simulation. A gain of over 6 dB has been measured using the new setup compared with a simple trajectory discrimination setup, achieving a very good agreement with the prediction.Publicad

Toward a quantitative model for suspended particle devices: optical scattering and absorption coefficients

Suspended particle devices (SPDs) allow rapid voltage-controlled modulation of their optical transmittance and are of interest for solar-energy-related and other applications. We investigated the spectral total and diffuse transmittance of an SPD, including its angular dependence. The optical modulation was large for visible light but almost nil in the infrared, and the devices had noticeable haze. A theoretical two-flux model was formulated and provided a quantitative description of the absorption and scattering coefficients and thereby of the detailed optical performance. This analysis gives a benchmark for assessing improvements of the SPD technology as well as for comparing it with alternative technologies for optical modulation.This work was supported in part by the Comunidad de Madrid (FACTOTEM2-CM, S2009/ESP-1781).Publicad

Efficient light management in a monolithic tandem perovskite /silicon solar cell by using a hybrid metasurface

Solar energy is now dealing with the challenge of overcoming the Shockley&-Queisser limit of single bandgap solar cells. Multilayer solar cells are a promising solution as the so-called third generation of solar cells. The combination of materials with different bandgap energies in multijunction cells enables power conversion efficiencies up to 30% at reasonable costs. However, interfaces between different layers are critical due to optical losses. In this work, we propose a hybrid metasurface in a monolithic perovskite-silicon solar cell. The design takes advantage of light management to optimize the absorption in the perovskite, as well as an efficient light guiding towards the silicon subcell. Furthermore, we have also included the effect of a textured back contact. The optimum proposal provides an enhancement of the matched short-circuit current density of a 20.5% respect to the used planar reference.This research was funded by Ministerio de Economía y Competitividad, grant number TEC2016-77242-C3-1-R Grant (AEI/FEDER, UE funds), and Comunidad de Madrid and FEDER program through the SINFOTON-CM Research (grant number S2013/MIT-2790) and SINFOTON2-CM (granT number S2018/NMT-4326) programs

Reconfigurable optical multiplexer based on liquid crystals for polymer optical fiber networks

In this work, different novel 3×1 multiplexer structures for being used in polymer optical fiber networks are proposed. Designs are compact, scalable, and of low consumption, capable of operating in a large wavelength range simultaneously 660, 850, and 1300 nm, due to the use of nematic liquid crystal cells. Light that comes from each input port is handled independently and eight operation modes are possible. Control electronics has been made using a programmable integrated circuit. Electronic system makes available the managing of the optical stage using a computer. An additional four optical sensors have been included for allowing the optical status checking. Finally, a polarization independent multiplexer has been implemented and tested. Insertion losses less than 4 dB and isolation better than 23 dB have been measured. In addition, 30-ms and 15-ms setup and rise times have been obtained. The proposed multiplexer can be used in any polymer optical fiber network, even in perfluorinated graded index one, and it can be specially useful in optical sensor networks, or in coarse wavelength division multiplexing networks.Publicad