Research areas

Radiofrequecy devices and subsystems

We design, develop and characterize radiofrequency components and subsystems for communications and sensing applications. This includes development of prototypes with hybrid integration technology in soft and ceramic substrates and accurate design of passive devices supported by full wave electromagnetic and circuit simulation.

We have designed highly integrated radiofrequency circuitry in Low Temperature Cofired Ceramic (LTCC) technology, as well as filters and ultrawideband directional couplers in multilayer technology. Further focuses of research are six-port architectures for multiband multiservice receivers and Phase noise reduction techniques for voltage controlled oscillators. Our measurement capabilities include radiofrequency and high speed electronics circuits up to 50 GHz with electro-optical components and modules.

Integrated optics and fiber optics

We design and characterize integrated optical components in several technologies for communications and sensing applications. This includes design of passive waveguide devices and interconnects with Computer Aided Design tools (BPM, EEM, FDTD) for Indium-Phosphide, Silicon-on-insulator and polymer platforms.

Our group has a strong expertise in waveguide diffraction gratings for fiber-to-chip and free-space-to-chip coupling, as well as high performance multimode interference coupler design. We currently investigate the use of subwavelength structures to enhance device performance and bandwidth. Our work includes phase and polarization diversity coherent receivers for 100Gb/s fiber optic communications, measurement techniques for integrated optical devices and high data-rate long-distance fiber optical transmission.

Biophotonics

We are developing integrated optical biosensors for label free detection of medically relevant analytes, such as cancer biomarkers. This includes the design of chip coupling solutions, such as grating couplers, novel sensing structures, and detection and multiplexation schemes. Furthermore, we will address surface functionalization and micro-fluidic integration.

Lines of research

Photonic Biosensors

This research line aims to: a) detect very low concentrations of drugs and pathogens and b) monitor molecular reactions in real-time for early diagnosis of diseases and drug discovery. The key advantage of photonic biosensors is that they enable label-free monitoring and detection, obviating intermediate labelling steps that can hamper detection reliability. Photonic biosensors based on integrated optics can be fabricated on a large scale, and, as opposed to surface plasmon resonance, their sensitivity is not limited by reduced propagation distances.

The Silicon-on-Insulator platform offers increased sensitivity for evanescent field sensors, and a high degree of miniaturization and integration, enabling parallelized probing. Parallelization allows for several different reactions to be monitored simultaneously, while at the same time performing redundancy checks to reduce false positive/negatives. In the silicon platform detection limits 0.3pg/mm² have been achieved thereby already outperforming existing commercial solutions. The overall goal of this line is to significantly enhance the sensitivity of biosensors, reduce their cost, and demonstrate these improvements in the detection of medically and or biologically relevant analytes such as TPSA (Total Prostatic Specific Antigen) found in prostatic cancer.

Nanostructured waveguides for optical communications and sensing

Optical communications are putting increasingly stronger specifications on optical components due to the increasing data transmission demand which has grown up more than 30% per year along the last decade. Also, intense research activity on different types of photonic sensors for a variety of applications as infrastructures, spectrometers and biosensors (which have a strong potential for early diagnosis of deseases and drug-discovery) is being developed troughout the world. Sub-wavelength gratings (SWGs), i.e. periodic structures in which diffraction is suppressed, are enabling new design approaches based on refractive index engineering. The size of these structures is currently close to the limit of state-of-art fabrication technologies, but with the continuous advance of lithographic techniques, such as extreme-ultraviolet (EUV), it will be possible to fabricate SWGs on a large scale in the coming years. In this line we aim to develop and apply SWG based concepts which will allow us to improve the performance of integrated optical components in Silicon on Insulator platform, for sensor (focusing on sensitivity) and communication (focusing on bandwidth) applications.

Optical coherent receivers for 100Gb/s

Due to the growing demand in transmission capacities, long-haul optical communication networks are advancing toward polarization multiplexed systems, and increasingly complex coherent modulation formats. Such systems require rugged, high-performance and cost-efficient receivers, for which integrated optical solutions are well suited. During last years, the group has greatly contributed to the development of first monolithically integrated coherent receiver in InP, capable of receiving phase modulated optical signals. Research is now being conducted to develop a monolithically integrated high speed coherent receiver for polarization multiplexed signals which will provide a low-cost solution for 1000Gbps POLMUX-QPSK signal demodulation.

Phase noise reduction for voltage controlled radiofrequency oscillators

Modern wireless technologies are today's main driver for telecom industry throughout the world. Mobile systems (GSM, EDGE,UMTS,LTE), wireless computer and peripherals access (WiFi, Wimax, Bluethooth) and RFID are some of the applications that are leading the growth of the telecom market. Low phase noise of radiofrequency synthesized sources is essential to meet stringent EVM ('Error Vector Magnitude') specified by modern wireless communication standards. Phase noise reduction of PLL based synthesizers is critical for test and measurement instrumentation required for modern wireless standards. In this instruments the phase noise outside the loop bandwidth is mainly limited by the voltage controlled oscillator. This research line aims to find solutions to reduce the phase noise of voltage controlled radiofrequency oscillators for frequencies well apart from the carrier (up to 1 MHz typical).

Fundings

• "Tecnologías de diseño para dispositivos nanofotónicos sobre silicio"
  (2007-2012) Dirección General de Investigación, Tecnología y Empresa (Junta de Andalucía) (P07-TIC-02946)
• "100Gbit/s Carrier-Grade Ethernet Transport Technologies",
  (2008-2010) CELTIC 100GTE Consortium, http://www.celtic-initiative.org/Projects/100GET/, (CELTIC CP4-001 100GET)”
• "Tecnologias para el diseño de componentes y sistemas de comunicaciones opticas coherentes de nueva generacion".
  (2009-2012) Programa Nacional de Tecnologías de la Información y de las Comunicaciones (TEC2009-10152)
• "Sistema para caracterización de componentes y subsistemas electroópticos integrados",
  Infraestructuras científico-tecnológicas del Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica, 2008-2011. Ministerio de Ciencia e Innovación (UNMA08-1E-016)
• "Monolithic InP-based Dual Polarization QPSK Integrated Receiver and Transmitter for CoHerent 100-400Gb Ethernet"
  MIRTHE, (2010-2013) EU Seventh framework programme, Theme ICT-2009.3.7: Photonics (Call FP7-ICT-2009-5, Ref. 257980)
• "Lazos de enganche en frecuencia para mejora de prestaciones de ruido de fase en generadores de instrumentación de radiofrecuencia",
  (2010-2014) Dirección General de Investigación, Tecnología y Empresa (Junta de Andalucía) (P09-TIC-5268)

Algunas publicaciones de interés

• Moscoso-Mártir, J.G. Wangüemert-Pérez, I. Molina-Fernández, E. Márquez-Segura ,
  Slot-Coupled Multisection Quadrature Hybrid for UWB Applications, IEEE Microwave and Wireless Components Letters, vol. 19, no. 3, pp. 143-145, March 2009
• R.Halir, P. Cheben, S. Janz, I. Molina-Fernandez, J.G. Wangüemert-Pérez,
  Waveguide grating coupler with sub-wavelength microstructures, Optics Letters, vol 34, no. 9, 1408-1410, May 2009
• R.Halir, I. Molina-Fernandez, J.G. Wangüemert-Pérez, A. Ortega-Moñux, J. de Oliva Rubio, P. Cheben,
  Characterization of Integrated Photonic Devices with Minimum Phase Technique, Optics Express, vol. 17, no.10, pp. 8349-8361, May 2009.
• Molina-Fernandez, A. Ortega-Moñux, J.G. Wangüemert-Pérez,
  Improving Multimode Interference Couplers Performance Through Index Profile Engineering, IEEE J. Lightwave Technol, vol. 27, no. 10, pp. 1307-1314, Mayo 2009
• Javier Perez Dueñas, J. G. Wangüermert-Pérez, I. Molina-Fernandez,
  Novel modulation scheme and six-port based RAKE receiver for DS-UWB”, IEEE Transactions on Wireless Communications, vol. 8, no. 7, pp. 3628-3633, Jul. 2009
• P. Pérez-Lara, J. A. Medina-Rodríguez, I. Molina-Fernández, J. G. Wangüemert-Pérez, A. González-Salguero,
  Wideband Homodyne Six-Port Receiver with High LO-RF Isolation”, IET Microw. Antennas Propag., vol. 3, no. 5, pp. 882-888, Aug. 2009
• Lopez-Berrocal, J. Oliva-Rubio, I. Molina-Fernandez,
  Design and implementation of DC-20GHz lumped resistor matched loads for planar microwave circuits, IEEE Microwave Theory Techniques, vol. 57, no. 10, pp. 2439-2443, Oct. 2009
• Robert Halir, A. Ortega-Moñux, Í. Molina-Fernández, J. G. Wangüemert-Pérez, Pavel Cheben, Dan-Xia Xu, Boris Lamontagne, and Siegfried Janz,
  Compact High Performance Multi-Mode Interference Couplers in Silicon-on-Insulator”, IEEE Photonics Technology Letters, vol. 21, no. 21, pp. 1600-1602, Nov 2009.
• Robert Halir, A. Ortega-Moñux, Í. Molina-Fernández, J. G. Wangüemert-Pérez, Pavel Cheben, Dan-Xia Xu, Boris Lamontagne, and Siegfried Janz,
  Integrated Optical Six-Port Reflectometer in Silicon-on-Insulator”, IEEE Journal of Lightwave Technology, , vol. 27, no 23, pp. 5405-5409, Dec. 2009
• M. Toril, I. Molina-Fernandez, V. Wille, C. Walshaw,
  Analysis of Heuristic Graph Partitioning methods for the assignment of Packet Control Units in Geran, Wireless Personal Communications, Springer Verlag, D.O.I. 10.1007/s11277-010-9963-1, Marzo 2010
• M. Toril, V. Wille, I. Molina-Fernandez, C. Walshaw,
  An Adaptive Multi-start Graph Partitioning Algorithm for Structuring Cellular Networks, Journal of Heuristics, SpringerVerlag (Aceptado)
• P. Pérez-Lara, I. Molina-Fernández, G. Wangüemert-Pérez and A. Rueda-Pérez,
  Broadband Five-Port Direct Receiver Based on Low-Pass and High-Pass Phase Shifters, IEEE Transactions on Microwave Theory and Techniques, vol. 58, no 4, pp. 849-853, April 2010
• Lopez-Berrocal, J. Oliva-Rubio, E. Márquez-Segura, A. Moscoso-Mártir, I. Molina-Fernandez, P. Uhlig,
  High performance 1.8-18 GHz 10 dB Low temperature co-fired ceramic directional coupler, Progress In Electromagnetics Research, PIER 104, 99-112, 2010. http://ceta.mit.edu/PIER/pier.php?volume=104
• Alonso, A. Ortega-Moñux, I. Molina-Fernandez, P. Cheben, L. Zavargo-Peche, R. Halir,
  Efficient fiber-to-chip grating coupler for micrometric SOI rib waveguides, Optics Express, vol. 18, no. 14, pp. 15189-15200, 2010
• Robert Halir, Pavel Cheben, Jens Schmid, Rubin Ma, Donald Bedard, Siegfried Janz, Dan-Xia Xu, Adam Densmore, Jean Lapointe, Íñigo Molina-Fernández,
  Continuously apodized fibre to chip surface grating coupler with refractive index engineered subwavelength structure, Optics Letters 35 (19), pp. 3243-3245, 2010
• C. Alonso-Ramos, A. Ortega-Moñux, L. Zavargo-Peche, R. Halir, J. de-Oliva-Rubio, I.Molina-Fernandez,P. Cheben, D.-X. Xu, S. Janz,B. Lamontagne,N. Kim,
  Single-etch grating coupler for micrometric rib waveguides, Optics Letters 15;36(14):2647-9, Jul-2011
• J. H. Schmid, P. Cheben, P. J. Bock, R. Halir, J. Lapointe, S. Janz, A. Delâge, A. Densmore, T. J. Hall, B. Lamontagne, R. Ma, I. Molina-Fernández, and D.-X. Xu ,
  Refractive Index Engineering with Subwavelength Gratings in Silicon Microphotonic Waveguides, IEEE Photonics Journal (Submitted)
• Ortega-Moñux, L. Zavargo-Peche, A. Maese-Novo, I. Molina-Fernández, R. Halir, J. G. Wangüemert-Pérez, P. Cheben, J. H. Schmid,
  High Performance Multimode Interference Coupler in Silicon Waveguides with Subwavelength Structures, IEEE Photonics Technology Letters, vol. 23, no. 19, pp. 1406- 1408, 2011
• J. H. Schmid, P. Cheben, P. J. Bock, R. Halir, J. Lapointe, S. Janz, A. Delâge, A. Densmore, J.-M. Fédeli, T. J. Hall, B. Lamontagne, R. Ma, I. Molina-Fernández, and D.-X. Xu,
  Refractive Index Engineering With Subwavelength Gratings in Silicon Microphotonic Waveguides, IEEE Photonics Journal, Focus Issue on Photonic Materials and Integration Architectures, pp. 597, 2011
• A. Moscoso-Martir, I. Molina-Fernandez, and A. Ortega-Monux,
  Signal Constellation Distortion and BER Degradation due to Hardware Impairments in Six-port Receivers with Analog I/Q generation , Progress In Electromagnetics Research, Vol. 121, 225-247, 2011
• R. Halir, R. Ma, L. Zavargo-Peche, D.-X. Xu, P. Cheben, J. H. Schmid, S. Janz, A. Densmore, A. Ortega-Moñux,Í. Molina-Fernández, and J.-M. Fédéli,
  Single etch grating couplers for mass fabrication with DUV Lithography, Optical and Quantum Electronics, (Springer Science+Business Media B.V.), 2012 (accepted)
• C.Alonso-Ramos, A. Ortega-Moñux, I. Molina-Fernandez, P. Cheben, L. Zavargo-Peche, R. Halir, S. Janz, D.-X. Xu, N. Kim, B. Lamontagne
  Grating couplers for thick SoI rib waveguides, Optical and Quantum Electronics (Springer Science+Business Media B.V.), Invited Paper, DOI 10.1007/s11082-012-9569-9
• P. J. Reyes-Iglesias, I. Molina-Fernandez, A. Moscoso-Martir, A. Ortega-Monux
  High Performance Monolithically Integrated 120° Downconverter with Relaxed Hardware Constraints Optics Express, Vol. 20, No. 2, pp. 1164-1171, Feb. 2012.
• Lopez-Berrocal, E. Márquez-Segura, I. Molina-Fernandez, J.C. Gonzalez-Delgado,
  A circuit model for vertical multilayer transitions in coplanar waveguide technology, Progress In Electromagnetics Research B (PIER B), Vol. 41, pp. 51-76, 2012

Patentes relacionadas

• I. Molina Fernandez, J.G. Wangüemert Perez, A. Ortega Moñux, M. Schell, R. Kunkel,
  Universidad de Málaga, Heinrich Hertz Institute Fraunhofer Institute
  "MULTIMODE INTERFERENCE COUPLER AND METHOD FOR THE STRUCTURAL CONFIGURATION THEREOF"
• Alvaro Moscoso Martir, I. Molina Fernandez,
  Universidad de Málaga, AT4wireless
  "Acoplador direccional acoplado por ranura y procedimiento de diseño de dicho acoplador"
• Robert. Halir, A. Maese-Novo, A. Ortega Moñux, I. Molina Fernandez,
  Universidad de Málaga
  "Dispositivo acoplador de guías de onda, y método de diseño de dicho dispositivo."
• Alonso Ramos, Carlos Alberto (UMA), Vivien, Laurent (UPS/CNRS), Cheben, Pavel (NRCC), Halir, Robert (UMA), Marris Morini, Delphine (UPS/CNRS), Ortega Moñux, Alejandro (PDI), Molina Fernández, Iñigo (PDI) Schmid, Jens Holger (NRCC), Janz, Siegfried (NRCC), Xu, Dan Xia (NRCC)
  Universidad de Málaga, Universite Paris Sud 11, Centre National de la Reserche Scientifique, National Research Council Canada
  "Highly Tolerant Tuneable Integrated Optical Polarization Rotator"