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Birth year 1956.

Academic degrees
1990 – University of Porto, Engineering Faculty, Porto, Portugal –
Completed the curricular part of the MSc degree in Telecommunications (1 year).
1986 – University of Porto, Science Faculty, Porto, Portugal –
Graduated in Physics, branch of Applied Physics, Optics and Electronics (5 years).

Professional experience
2007 – present - INESC Porto / INESC TEC –
Optical fiber sensors: electronic design, implementation and test; software development, system integration and data
2005 – 2007 - FiberSensing – Sistemas Integrados de Monitorização (Now HBM FiberSensing) –
Design and test of front-end electronics for signal conditioning.
Software development for sub-system and equipment testing and quality control.
1986 – 2005 - INESC Porto
Optical fiber communications, design, implementation and test: Tx/Rx, clock distribution and clock recovery.
Wireless infrared communications: R&D and technology transfer activities
Organized and taught technical courses on optical communications and instrumentation electronics.
Supervised or assisted the work of graduate and post-graduate students.

Other Professional Activities
1987 – CERN, Geneva, Switzerland (Training internship)
Study of Surface Mount Technology and implementation of front-end amplifier (6 months)
2002 – Ciência Viva, Lisboa, Portugal
National fair to promote science and technology among high-school students (1 week)
2004 – Hannover Messe, Germany
Presented fiber Bragg grating measurement system prototype, developed at INESC Porto (1 week)
2005 – University of Oxford, UK (Courses attended)
High-Speed Digital Design and Advanced High-Speed Signal Propagation courses (1 week)
Teaching in Training Courses
1992 – 1993 – FUNDETEC, Técnicos Especialistas em Electrónica e Telecomunicações
1993 – 1994 – Fibras Ópticas
Development of Courses for Computer Based Training
1990 - IN#TEL#EC - Integrated Telecommunications Training for the European Community, COMETT 90/1/5390/Cc
1993 – 1994 – EAC, Formação de Técnicos Especialistas em Optoelectrónica

Main areas of interest
Optical communications, both fibre-based and wireless infrared.
Phase-locked loop circuits, namely clock recovery and frequency multiplication.
PCB interconnection technologies, for high-speed electronic circuits.
Optical fibre sensors.
Low-noise electronics.
Signal conditioning.

Software skills
LabView (National Instruments)
MatLab (Mathworks)
OptSim (Artis Software, now sold by RSoft/Synopsys)
SPICE (Berkeley University)
Eagle (CadSoft)



  • Name

    João Ferreira
  • Role

    External Research Collaborator
  • Since

    01st June 1986
  • Nationality

  • Centre

    Applied Photonics
  • Contacts



ECOAL Project-Delivering Solutions for Integrated Monitoring of Coal-Related Fires Supported on Optical Fiber Sensing Technology

Ribeiro, J; Viveiros, D; Ferreira, J; Lopez Gil, A; Dominguez Lopez, A; Martins, HF; Perez Herrera, R; Lopez Aldaba, A; Duarte, L; Pinto, A; Martin Lopez, S; Baierl, H; Jamier, R; Rougier, S; Auguste, JL; Teodoro, AC; Goncalves, JA; Esteban, O; Santos, JL; Roy, P; Lopez Amo, M; Gonzalez Herraez, M; Baptista, JM; Flores, D;


The combustion of coal wastes resulting from mining is of particular environmental concern, and the importance of proper management involving real-time assessment of their status and identification of probable evolution scenarios is recognized. Continuous monitoring of the combustion temperature and emission levels of certain gases allows for the possibility of planning corrective actions to minimize their negative impact on the surroundings. Optical fiber technology is well suited to this purpose and here we describe the main attributes and results obtained from a fiber optic sensing system projected to gather data on distributed temperature and gas emissions in these harsh environments.


Ammonia Sensing System Based on Wavelength Modulation Spectroscopy

Viveiros, D; Ferreira, J; Silva, SO; Ribeiro, J; Flores, D; Santos, JL; Frazao, O; Baptista, JM;


A sensing system in the near infrared region has been developed for ammonia sensing based on the wavelength modulation spectroscopy (WMS) principle. The WMS is a rather sensitive technique for detecting atomic/molecular species, presenting the advantage that it can be used in the near-infrared region by using the optical telecommunications technology. In this technique, the laser wavelength and intensity were modulated by applying a sine wave signal through the injection current, which allowed the shift of the detection bandwidth to higher frequencies where laser intensity noise was typically lower. Two multi-pass cells based on free space light propagation with 160 cm and 16 cm of optical path length were used, allowing the redundancy operation and technology validation. This system used a diode laser with an emission wavelength at 1512.21 nm, where NH3 has a strong absorption line. The control of the NH3 gas sensing system, as well as acquisition, processing and data presentation was performed.


Fiber Optic Sensing System for Temperature and Gas Monitoring in Coal Waste Pile Combustion Environments

Viveiros, D; Ribeiro, J; Ferreira, J; Lopez Aldaba, A; Pinto, AMR; Perez Herrera, RA; Diaz, S; Lopez Gil, A; Dominguez Lopez, A; Esteban, O; Martin Lopez, S; Auguste, JL; Jamier, R; Rougier, S; Silva, SO; Frazao, O; Santos, JL; Flores, D; Roy, P; Gonzalez Herraez, M; Lopez Amo, M; Baptista, JM;


It is presented an optical fiber sensing system projected to operate in the demanding conditions associated with coal waste piles in combustion. Distributed temperature measurement and spot gas sensing are requirements for such a system. A field prototype has been installed and is continuously gathering data, which will input a geological model of the coal waste piles in combustion aiming to understand their dynamics and evolution. Results are presented on distributed temperature and ammonia measurement, being noticed any significant methane emission in the short time period considered. Carbon dioxide is also a targeted gas for measurement, with validated results available soon. The assessment of this technology as an effective and reliable tool to address the problem of monitoring coal waste piles in combustion opens the possibility of its widespread application in view of the worldwide presence of coal related fires.


Monitoring of Coal Waste Piles With Fiber Optic Sensing Technology

Viveiros, D; Ribeiro, J; Ferreira, J; Pinto, AMR; Perez Herrera, RA; Diaz, S; Lopez Gil, A; Dominguez Lopez, A; Esteban, O; Martins, HF; Martin Lopez, S; Baierl, H; Auguste, JL; Jamier, R; Rougier, S; Santos, JL; Flores, D; Roy, P; Gonzalez Herraez, M; Lopez Amo, M; Baptista, JM;


Coal has been for centuries a central energy source to fulfill industrial and domestic needs. Its large scale extraction produced huge amount of debris that were piled in the neighboring of the mines, quite often going into combustion triggered by events like forest fires or lightning. When in this state it can continue for years, releasing substantial emissions of toxic and greenhouse gases with recognized impact in the environment and, more serious in the short term, in the life quality of the populations located nearby. Continuous monitoring of combustion temperature and emission levels of certain gases opens the possibility to plan corrective actions to minimize their negative impact. Optical fiber technology is wellsuited to this purpose and here it is described the main attributes of a fiber optic sensing system projected to gather data on distributed temperature and gas emission in these harsh environments.


Environmental monitoring of S. Pedro da Cova waste pile: Combustion temperature [Monitorização ambiental de escombreira de S. Pedro da Cova: Temperatura de combustão]

Ribeiro, J; Viveiros, D; Ferreira, J; Santos, JL; Baptista, JM; Flores, D;

Comunicacoes Geologicas

Despite the socio-economic importance of mining in Douro Coalfield, the coal exploitation and utilization originated impacts on the environment. From these stands out the S. Pedro da Cova waste pile which is self-burning since 2005. The potential environmental impacts associated with this coal waste pile include: air pollution caused by the gaseous emissions and dispersion of solid particles; pollution of soils, surface and groundwater caused by mobilization of solid particles, leaching of hazardous elements, dissolution of neoformed and deposition of solid particles; landslides and mass movements also caused the weathering agents, and deterioration of vegetation that may also be due to the acid drainage. The main objective of this work is the combustion temperature monitoring in S. Pedro da Cova waste pile using the infrared thermography technique. The acquired results during the temperature monitoring campaigns allow the study of the dynamics and evolutionary scenarios of the self-burning process in the coal waste pile, contributing to a precise definition of the risks to the environment and human health. © 2014, LNEG – Laboratório Nacional de Geologia e Energia IP.