DTE - GOTL - Artículos de Revistas

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Now showing 1 - 20 of 42
  • Publication
    Ultra-Wideband Multi-Octave Planar Interconnect for Multi-Band THz Communications
    (Springer, 2023-08-01) Iwamatsu, Shuya; Ali, Muhsin; Fernandez Estevez, Jose Luis; Tebart, Jonas; Kumar, Ashish; Makhlouf, Sumer; Carpintero del Barrio, Guillermo; Stohr, Andreas; European Commission
    An ultra-wideband (UWB) interconnect technology using indium phosphide (InP)-based transitions for coupling the output signals from terahertz (THz) photodiodes featuring coplanar waveguide (CPW) outputs to low-loss dielectric rod waveguides (DRWs) is presented. The motivation is to exploit the full bandwidth offered by THz photodiodes without limitations due to standard rectangular waveguide interfaces, e.g., for future high data rate THz communications. Full electromagnetic wave simulations are carried out to optimize the electrical performance of the proposed InP transitions in terms of operational bandwidth and coupling efficiency. The transitions are fabricated on 100-µm-thin InP and integrated with silicon (Si) DRWs. Experimental frequency domain characterizations demonstrate efficient THz signal coupling with a maximum coupling efficiency better than - 2 dB. The measured 3-dB and 6-dB operational bandwidths of 185 GHz and 280 GHz, respectively, prove the multi-octave ultra-wideband features of the developed interconnect technology. The 6-dB operational bandwidth covers all waveguide bands between WR-12 to WR-3, i.e., a frequency range between 60 and 340 GHz. In addition, the multi-octave performances of the fabricated interconnects were successfully exploited in proof-of-concept THz communication experiments. Using intermediate frequency orthogonal frequency division multiplexing (OFDM), THz communications are demonstrated for several frequency bands using the same interconnect. Considering soft-decision forward error correction, error-free transmission with data rates of 24 Gbps at 80 GHz and 8 Gbps at 310 GHz is achieved
  • Publication
    Variable Configuration Fiber Optic Laser Doppler Vibrometer System
    (Springer Nature, 2016-06-01) Posada Román, Julio Enrique; Jackson, David A.; García Souto, José Antonio
    A multichannel heterodyne fiber optic vibrometer is demonstrated which can be operated at ranges in excess of 50 m. The system is designed to measure periodic signals, impacts, rotation, 3D strain, and vibration mapping. The displacement resolution of each channel exceeds 1 nm. The outputs from all channels are simultaneous, and the number of channels can be increased by using optical switches
  • Publication
    Novel thermal annealing methodology for permanent tuning polymer optical fiber Bragg gratings to longer wavelengths
    (Optica Publishing Group, 2018-01-12) Pospori, A.; Marques, C.A.F.; Sagias, Georgios; Lamela Rivera, Horacio; Webb, D.J.
    The Bragg wavelength of a polymer optical fiber Bragg grating can be permanently shifted by utilizing the thermal annealing method. In all the reported fiber annealing cases, the authors were able to tune the Bragg wavelength only to shorter wavelengths, since the polymer fiber shrinks in length during the annealing process. This article demonstrates a novel thermal annealing methodology for permanently tuning polymer optical fiber Bragg gratings to any desirable spectral position, including longer wavelengths. Stretching the polymer optical fiber during the annealing process, the period of Bragg grating, which is directly related with the Bragg wavelength, can become permanently longer. The methodology presented in this article can be used to multiplex polymer optical fiber Bragg gratings at any desirable spectral position utilizing only one phase-mask for their photo-inscription, reducing thus their fabrication cost in an industrial setting. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
  • Publication
    Invited Article: Experimental evaluation of gold nanoparticles as infrared scatterers for advanced cardiovascular optical imaging
    (2018-08-01) Hu, Jie; Lamela Rivera, Horacio; Leggio, Luca; Gallego Cabo, Daniel; Ministerio de Economía y Competitividad (España)
    The tremendous impact that cardiovascular diseases have in modern society is motivating the research of novel imaging techniques that would make possible early diagnosis and, therefore, efficient treatments. Cardiovascular optical coherence tomography (CV-OCT) emerged as a result of such a demand, and it has already been used at the clinical level. Full utilization of CV-OCT requires the development of novel contrast molecular agents characterized by a large scattering efficiency in the infrared (800-1400 nm). Gold nanoparticles (GNPs) seem to be the best candidates, but their scattering properties in the infrared are hardly known. In most of the cases, scattering properties are extracted from numerical simulations. This knowledge gap here is covered by providing an experimental evaluation of the infrared scattering properties of different GNPs (nanoshells, nanostars, and nanorods). These GNPs display remarkable extinction coefficients in the first and second biological windows, including the particular CV-OCT wavelength. We use a unique combination of techniques (thermal loading experiments, infrared optical coherence tomography, infrared dark field microscopy, and optoacoustic spectroscopy) to experimentally determine the scattering efficiency at three different near-infrared wavelengths (808 nm, 980 nm, and 1280 nm), lying in the first and second biological windows. Consequently, this work determines experimentally the influence of particle morphology on the infrared scattering efficiency of GNPs and evidences the existence of remarkable discrepancies between experimental data and numerical simulations. (C) 2018 Author(s).
  • Publication
    Wireless Data Transmission at Terahertz Carrier Waves Generated from a Hybrid InP-Polymer Dual Tunable DBR Laser Photonic Integrated Circuit
    (Springer Nature, 2018-02-14) Carpintero del Barrio, Guillermo; Hisatake, Shintaro; Felipe, David De; Guzmán Martínez, Robinson Cruzoe; Nagatsuma, Tadao; Keil, Norbert; Ministerio de Economía y Competitividad (España)
    We report for the first time the successful wavelength stabilization of two hybrid integrated InP/Polymer DBR lasers through optical injection. The two InP/Polymer DBR lasers are integrated into a photonic integrated circuit, providing an ideal source for millimeter and Terahertz wave generation by optical heterodyne technique. These lasers offer the widest tuning range of the carrier wave demonstrated to date up into the Terahertz range, about 20 nm (2.5 THz) on a single photonic integrated circuit. We demonstrate the application of this source to generate a carrier wave at 330 GHz to establish a wireless data transmission link at a data rate up to 18 Gbit/s. Using a coherent detection scheme we increase the sensitivity by more than 10 dB over direct detection.
  • Publication
    300 GHz optoelectronic transmitter combining integrated photonics and electronic multipliers for wireless communication
    (MDPI, 2019-03-27) Ali, Muhsin; Perez Escudero, Jose Manuel; Guzmán Martínez, Robinson Cruzoe; Lo, Mu Chieh; Ederra, Iñigo; Blanco Gonzalo, Ramón; García Muñoz, Luis Enrique; Santamaría-Botello, Gabriel Arturo; Segovia Vargas, Daniel; Van Frederic, Dijk; Carpintero del Barrio, Guillermo; European Commission; Ministerio de Economía y Competitividad (España)
    THz communications systems at carrier frequencies above 200 GHz are the key to enable next-generation mobile communication networks with 100 Gbit/s wireless data rates. One of the key questions is, which carrier frequency generation technique will be the most suitable. This is currently addressed by two separate approaches, electronics-based and photonics-based. We present in this paper a truly microwave photonic approach that benefits from the main key features of each, bandwidth, tunability, stability and fiber compatibility from photonics and power handling capability from the electronics. It is based on a Photonic Local Oscillator (PLO), generating a 100 GHz frequency, fed into an electronic frequency multiplier. A high speed uni-travelling carrier photodiode (UTC-PD) provides the 100 GHz PLO for Schottky tripler diodes, generating 300 GHz signal. To feed the UTC-PD, we present a photonic integrated mode locked laser source. According to the simulations and measurements, the developed transmitter can produce a maximum of 12 muW of THz power at 280 GHz.
  • Publication
    28 GBd PAM-8 transmission over a 100 nm range using an InP-Si3N4 based integrated dual tunable laser module
    (OSA, 2021-05-24) Dass, Devika; Troncoso Costas, Marcos; Barry, Liam P.; O'Duill, Sean; Roeloffzen, Chris G. H.; Geuzebroek, Douwe; Carpintero del Barrio, Guillermo; Guzmán Martínez, Robinson Cruzoe; Browning, Colm
    This paper describes the detailed characterization of a novel InP-Si3N4 dual laser module with results revealing relative intensity noise (RIN) as low as -165 dB/Hz and wide wavelength tunability (100 nm). The hybrid coupled laser is deployed in an unamplified 28 GBd 8 level pulse amplitude modulation (PAM) short-reach data center (DC) transmission system. System performance, which is experimentally evaluated in terms of received signal bit error ratio (BER), demonstrates the ability of the proposed laser module to support PAM-8 transmission across a 100 nm tuning range with less than 1 dB variance in receiver sensitivity over the operating wavelength range. Comparative performance studies not only indicate that the proposed source can outperform a commercial external cavity laser (ECL) in an intensity modulation/direct detection (IM/DD) link but also highlight the critical impact of RIN in the design of advanced modulation short-reach systems.
  • Publication
    In the shadow of the laser phantom needle cross: dynamic air-plasma aperture sheds light on terahertz microscopy
    (Springer Nature, 2022-05-20) Headland, Daniel Jonathan; Withayachumnankul, Withawat
    Two plasma filaments crossing above the target create a subwavelength window for terahertz microscopy that excludes any subwavelength probe in vicinity.
  • Publication
    Millimeter-wave multiplexed wideband wireless link using rectangular-coordinate orthogonal multiplexing (ROM) antennas
    (IEEE, 2021-12-15) Tomura, Takashi; Hirokawa, Jiro; Ali, Muhsin; Carpintero del Barrio, Guillermo
    This paper is the first demonstration of multiplexed wideband data transmission in the millimeter-wave range using rectangular-coordinate orthogonal multiplexing (ROM) antennas. This spatial wireless multiplex communication method can be applied at several hundred GHz for further improvements in the data rate because much wider bandwidth is available and this multiplexing method does not require any signal processing. The multiplexing is achieved through the spatial eigenmodes of a novel antenna based on a rectangular coordinate system and magic-T which eliminates the need for computational signal processing efforts. The aperture distributions of these spatial eigenmodes are designed to have different polarities to avoid crosstalk and operate over a wide bandwidth range. We demonstrate their performance with four eigenmodes, achieving crosstalk between modes below -37.8 dB over a 14.6% relative bandwidth (57-66 GHz). We have introduced these antennas on a photonics-enabled real-time wireless data transmission, transmitting over two channels simultaneously, without any signal processing at the transmitter (multiplex) or the receiver (demultiplex). The two multiplexed channels show a total data rate up to 9.0 Gbps at most (5.875 Gbps and 3.125 Gbps for each channel) limited by the bandwidth of the low noise amplifiers at the receiver. The measured bit error rate (BER) is below the forward error correction (FEC) limit.
  • Publication
    InP integrated optical frequency comb generator using an amplified recirculating loop
    (Optica Publishing Group, 2022-11-09) Tough, Euan J.; Fice, Martyn J.; Carpintero del Barrio, Guillermo; Renaud, Cyril C.; Seeds, Alwyn J.; Balakier, Katarzyna
    A novel realisation of photonically integrated optical frequency comb generation is demonstrated on indium phosphide (InP) using a generic foundry platform. The architecture, based on the amplified recirculating loop technique, consists of cascaded electro-optic phase modulators embedded within a short waveguide loop. While an injected continuous wave laser signal is recirculated by the loop, the modulators are driven with a modulation frequency corresponding to the round-trip loop length frequency. This results in many phase coherent, evenly spaced optical comb lines being generated. The choice of InP as an integration platform allows immediate optical amplification of the modulated signal by embedded semiconductor optical amplifiers, enabling loop losses to be compensated and expanding the comb across broad optical bandwidths. This approach reduces the requirement for external, high-power optical amplifiers, improving the compactness and power efficiency of the full system. The system was modelled to identify off-resonance behaviour, outlining limits in matching both the modulation frequency and seed laser frequency to the round-trip loop frequency for optimal comb line generation to be achieved. The experimental device occupied a fraction of the 6 x 2 mm2 InP chip and operated at round-trip loop frequencies of 6.71 GHz to produce 59 comb lines within a 20 dB power envelope. All comb lines exhibited strong phase coherence as characterised by low composite phase noise measurements of -105 dBc/Hz at 100 kHz. A second device is also presented with a shorter loop length operating at ~10 GHz which generated 57 comb lines. Both loop configurations included short waveguide phase shifters providing a degree of tunability of the free spectral range with a tuning range of 150 MHz for small injection currents of less than 2.5 mA.
  • Publication
    Coherent photonic Terahertz transmitters compatible with direct comb modulation
    (Nature Research, 2022-06-09) González Guerrero, Luis; Carpintero del Barrio, Guillermo; European Commission
    We present a novel approach to coherent photonic THz systems supporting complex modulation. The proposed scheme uses a single optical path avoiding the problems of current implementations, which include: phase decorrelation, 3-dB power loss, and polarization and power matching circuits. More importantly, we show that our novel approach is compatible with direct modulation of the output of an optical frequency comb (i.e., not requiring the demultiplexing of two tones from the comb), further simplifying the system and enabling an increase in the transmitted RF power for a fixed average optical power injected into the photodiode.
  • Publication
    Cascaded directional coupler-based polarization splitter/combiner on commercial silicon photonics integration platform
    (Society of Photo-Optical Instrumentation Engineers (SPIE), 2023-03-17) Spanidou, Kalliopi; Orbe Nava, Luis Jorge; González Guerrero, Luis; Hermann, Dan; Carpintero del Barrio, Guillermo; European Commission; Universidad Carlos III de Madrid
    Silicon photonic (SiPho) platforms hold vast potential for providing multi-functional processing capabilities, such as filtering, mode-handling, modulation, etc. Structures for polarization manipulation have become essential elements to enhance channel capacity and to facilitate polarization multiplexing functions. Therefore, 1x2 polarization beam splitters (PBS) are introduced as polarization-division key building blocks based on a silicon-on-insulator (SOI) platform for separating/combining the fundamental modes. By cascading three bent directional couplers (DC), high-performance coupling characteristics can be obtained similar to those of asymmetric ones. A first-ever integration of this kind of PBS has been achieved utilizing Tower Semiconductor's PH18MA silicon photonics platform, which offers 180 nm SOI process technology. In this work, both output ports of the proposed PBS are being tested for polarization filtering across a polarization sweep. The advanced features of this integration process pave the way for next-generation coherent transceivers and aim to meet future optical interconnecting requirements. Furthermore, Synopsys OptoCompiler and the Photonic IC Design Flow, featured in Tower¿s process design kit (PDK), were used to design the devices.
  • Publication
    Photonic-based integrated sources and antenna arrays for broadband wireless links in terahertz communications
    (IOP Science, 2019-05) García Muñoz, Luis Enrique; Abdalmalak Dawoud, Kerlos Atia; Santamaría Botello, Gabriel Arturo; Rivera Lavado, Alejandro; Segovia Vargas, Daniel; Castillo Aranibar, P.; Van Dijk, F.; Nagatsuma, T.; Brown, E.R.; Guzmán Martínez, Robinson Cruzoe; Lamela Rivera, Horacio; Carpintero del Barrio, Guillermo; Ministerio de Economía y Competitividad (España)
    This paper analyzes integrated components for ultra-broadband millimeter-wave wireless transmitters enabling the 5 G objective to increase the wireless data rates 10x to 100x . We have pursued the photonic-based approach to generate the millimeter-wave carrier (approximate to 97GHz in this paper) through photomixing. We have achieved up to 10 Gb s(-1) data rate using an OOK modulation format (to reduce latency) and either direct detection (DD) or coherent detection. We show that coherent detection enables a sensitivity improvement of 17 dB over DD. We also demonstrate in this work that such improvement can be achieved using as the transmitter a novel integrated antenna array-the self-complementary chessboard array. This avoids the use of complex coherent schemes at the receiver, enabling simple DD for ultra-broadband links.
  • Publication
    Beam-shaping design for multi-wavelength diode laser stack system coupled into optical fiber for biomedical applications
    (ELSEVIER BV, 2021-12) Leggio, Luca; Gallego Cabo, Daniel; Gawali, Sandeep Babu; Wisniowski, Bartosz Norbert; Varona Ortega, Omar Enrique de
    Multispectral diode laser sources are extensively used for a variety of applications involving the identification of small objects based on their spectral signature. Although the power scaling of single emitters is severely limited, they are easily stackable as diode laser bars and stacks, allowing the combination of wavelengths and power levels required for each application. However, a critical drawback given by this topology is the asymmetry between the fast and the slow axes in the beam profile, leading to poor beam quality and possibly poor fiber coupling efficiency. In this regard, a suitable beam shaping is required to maximize the power coupling in the smallest possible fiber core. In this work, we propose an innovative beam shaping method for the homogenization of the beam quality of six 8-bar diode laser stacks at wavelengths from 790 nm to 980 nm. We performed realistic simulations to examine the shaping method with, when possible, commercially available components. Fast-axis collimating (FAC) lenses and beam twisters are designed in Zemax to remodel the far-field beam emitted by each bar. The beam of each diode laser stack is halved in the vertical axis using polarization beam combiners, and then three quartz-plate stacks combine and rearrange the beams coming from each diode laser stack pair in the horizontal axis to eliminate the lightless regions. A single multispectral beam is then obtained by using reflective and dichroic mirrors and effectively coupled into an optical fiber with a core diameter of 1 mm and a numerical aperture (N.A.) of 0.5 using a doublet of cylindrical lenses. A maximum power density of ~ 0.73 MW/cm2 is calculated at the output of the fiber with a fiber coupling of 89 %. A number of applications can benefit from the proposed topology, in particular biomedical applications using fiber probes are identified as potential candidates for the implementation of the proposed system.
  • Publication
    Overdrive short pulse high peak power diode lasers without catastrophic optical damage
    (IEEE, 2021-08) Sánchez Rodas, Miguel; Gallego Cabo, Daniel; Lamela Rivera, Horacio; Comunidad de Madrid
    Light Imaging Detection and Ranging (LIDAR) and Optoacoustic biomedical imaging techniques are applications that have a specific laser source requirements: short pulses, high peak power per pulse and high repetition rates. A custom current driver has been designed to fulfill these requirements and characterized in order to generate high current short pulses to drive High Power Diode Lasers (HPDL) beyond their maximum rating value, with a maximum current capacity of 120 A in a range of less than 10 nanoseconds pulse width, rise times up to 2 ns and a repetition rate of 1 kHz. Four commercial HPDLs have been driven generating optical pulses of less than 10 ns and more than four times the maximum rated optical peak power. A single laser device reached a maximum peak power of 880.6 W at 6 ns pulse width, demonstrating stable operation without catastrophic optical damage and improving the typical operation characteristics of the HPDLs for high speed short pulse applications.
  • Publication
    A photonically-excited leaky-wave antenna array at E-band for 1-D beam steering
    (MDPI, 2020-05-18) Pascual García, Alvaro J.; Ali, Mushin; Carpintero del Barrio, Guillermo; Ferrero, Fabien; Brochier, Laurent; Sauleau, Ronan; García Muñoz, Luis Enrique; Gonzalez Ovejero, David; European Commission; Ministerio de Economía y Competitividad (España)
    This manuscript reports the first leaky-wave antenna (LWA) array excited by a photomixer as well as its potential application for alignment in wireless links. The designed array is manufactured in printed circuit board (PCB) technology, works at the E-band (from 75 to 85 GHz), and provides a directive beam of about 18 dBi with a frequency scanning span of 22°. The antenna element consists of a microstrip line periodically loaded with stubs, and it has been designed employing a hybrid approach combining full-wave simulations and transmission line theory. This approach enables the optimization of the periods when the open-stopband of the LWA is mitigated or removed at the frequency of broadside emission. The proposed antenna was first tested using a ground signal ground (GSG) probe; the measured return loss and radiation patterns of the fabricated prototype were in good agreement with full-wave simulations. Then, the LWA array was integrated with the photomixer chip using conductive epoxy threads. Measurements of the radiated power yielded a maximum of 120 µW at 80.5 GHz for a 9.8 mA photocurrent. Finally, the antenna was used in a 25 cm wireless link, obtaining a 2.15 Gbps error-free data rate.
  • Publication
    Monolithically integrated microwave frequency synthesizer on InP generic foundry platform
    (IEEE, 2018-10-01) Lo, Mu Chieh; Zarzuelo García, Alberto; Guzmán Martínez, Robinson Cruzoe; Carpintero del Barrio, Guillermo; European Commission
    A photonic integrated circuit for microwave generation is proposed and experimentally validated. On the microchip, two tunable monochromatic lasers spectrally separated by 0-10.7 nm are monolithically integrated with one high-speed photodiode in heterodyne configuration for enabling continuous RF synthesis from 2 to 42 GHz. Under free-running operation, the two lasers with 20-40 MHz optical linewidth produce RF beat note with ~90 MHz electrical linewidth at the on-chip photodiode. This is the first demonstration of such a fully integrated microwave photonic generator developed within an open-access generic foundry platform.
  • Publication
    Femtosecond pulse and terahertz two-tone generation from facet-free multi-segment laser diode in InP-based generic foundry platform
    (OSA Publishing, 2018-07-09) Lo, Mu Chieh; Guzmán Martínez, Robinson Cruzoe; Carpintero del Barrio, Guillermo
    In this paper, a monolithically integrated similar to 1.55 mu m semiconductor laser in the fourth harmonic colliding pulse mode locking configuration is reported. This device was developed within a multi-project wafer run at an InP-based active-passive generic foundry. The 1.66-mm Fabry-Perot cavity is formed with two on-chip reflector building blocks rather than cleaved facets. In the cavity, three absorber sections symmetrically divide the cavity in four gain segments. This laser diode is able to emit 100-GHz pulse trains with 500-fs pulse duration as well as two-tone emissions with a frequency separation of 2.7 THz. The dependence of the spectral behavior on the forward bias current for gain sections and the reverse bias voltage for absorber sections are experimentally demonstrated.
  • Publication
    InP femtosecond mode-locked laser in a compound feedback cavity with a switchable repetition rate
    (OSA Publishing, 2018-02-01) Lo, Mu Chieh; Guzmán Martínez, Robinson Cruzoe; Carpintero del Barrio, Guillermo; Comunidad de Madrid; European Commission; Ministerio de Economía y Competitividad (España)
    A monolithically integrated mode-locked semiconductor laser is proposed. The compound ring cavity is composed of a colliding pulse mode-locking (ML) subcavity and a passive Fabry-Perot feedback subcavity. These two 1.6 mm long subcavities are coupled by using on-chip reflectors at both ends, enabling harmonic mode locking. By changing DC-bias conditions, optical mode spacing from 50 to 450 GHz is experimentally demonstrated. Ultrafast pulses shorter than 0.3 ps emitted from this laser diode are shown in autocorrelation traces.
  • Publication
    1.8-THz-wide optical frequency comb emitted from monolithic passively mode-locked semiconductor quantum-well laser
    (Optical Society of America, 2017-09-25) Lo, Mu Chieh; Guzmán Martínez, Robinson Cruzoe; Ali, Muhsin; Santos, Rui; Agustin, Luc; Carpintero del Barrio, Guillermo
    We report on an optical frequency comb with 14 nm (∼1.8 THz) spectral bandwidth at a −3 dB level that is generated using a passively mode-locked quantum-well laser in photonic integrated circuits fabricated through an InP generic photonic integration technology platform. This 21.5-GHz colliding-pulse mode-locked laser cavity is defined by on-chip reflectors incorporating intracavity phase modulators followed by an extracavity semiconductor optical amplifier as a booster amplifier. A 1.8-THz-wide optical comb spectrum is presented with an ultrafast pulse that is 0.35 ps wide. The radio frequency beat note has a 3-dB linewidth of 450 kHz and 35-dB SNR.