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About

About

Jose Manuel Marques Martins de Almeida received the
Graduate degree in applied physics (optics and electronics)
in 1987 and the Ph.D. degree in 1998 from the
University of Porto, Porto, Portugal. Since 2000, he has the
position of an Associate Professor at the Department of
Physics, Universidade de Trás os Montes e Alto Douro, Vila
Real, Portugal, and received Habilitation in 2006 from the
same University. He is currently a Senior Researcher in the
Centre for Applied Photonics of INESC TEC, Porto. His current
research interests include optical sensors, integrated
optics, spectroscopy, and biophysics.

Interest
Topics
Details

Details

  • Nationality

    Portugal
  • Centre

    Applied Photonics
  • Contacts

    +351220402301
    jose.almeida@inesctec.pt
002
Publications

2023

Refractometric sensitivity of Bloch surface waves : perturbation theory calculation and experimental validation

Authors
Dias, BS; De Almeida, JMMM; Coelho, LCC;

Publication
OPTICS LETTERS

Abstract
The sensitivity of one-dimensional Bloch surface wave (BSW) sensors to external refractive index variations using Kretschmann's configuration is calculated analytically by employing first-order perturbation theory for both TE and TM modes. This approach is then validated by com- parison with both transfer matrix method simulations and experimental results for a chosen photonic crystal structure. Experimental sensitivities of (8.4 +/- 0.2)x102 and (8.4 +/- 0.4)x102 nm/RIU were obtained for the TE and TM BSW modes, corresponding to errors of 0.02% and 4%, respectively, when comparing with the perturbation the- ory approach. These results provide interesting insights into photonic crystal design for Bloch surface wave sensing by casting light into the important parameters related with sen- sor performance.(c) 2023 Optica Publishing Group

2023

Compact biosensor system for the quantification of hydrogen peroxide in milk

Authors
Vasconcelos, H; Matias, A; Mendes, J; Araujo, J; Dias, B; Jorge, PAS; Saraiva, C; de Almeida, JMMM; Coelho, LCC;

Publication
TALANTA

Abstract
Hydrogen peroxide is usually added to products to delay the development of microorganisms mainly in milk, hence increasing its stability over time, however the side effects can become devastating to human health.A technique is presented consisting of detecting hydrogen peroxide as an adulterant in milk through a sensor where pretreatment of the sample is not necessary, using a single use membrane. The detection of hydrogen peroxide in fresh-raw, whole, semi-skimmed and skimmed milk was performed using a luminol chem-iluminescence reaction.For hydrogen peroxide water solutions, a linear response was attained from 1.0 x 10-4 to 9.0 x 10-3 %w/w and an LOD (limit of detection) of 3.0 x 10-5 %w/w was determined. An R-squared value of 0.97 and a relative standard deviation lower than 10%, were achieved.Hydrogen peroxide concentration as low as 1.0 x 10-3 %w/w was measured for fresh-raw, skim and whole milk and for semi-skimmed milk, as low as 2.0 x 10-3 %w/w.The methodology presented, as long as our knowledge, is original, rapid, ecological and inexpensive. In regard of the sensitivity obtained, the methodology has great possibility to be applied in the detection of hydrogen peroxide in several areas. It is envisaged monitoring of food quality, agriculture systems and environment pollution.

2023

Measuring Water Vapor Sorption Hysteresis of Cement Paste through an Optical Fiber Sensor

Authors
da Silva, PM; Coelho, LCC; de Almeida, JMMM;

Publication
CHEMOSENSORS

Abstract
Water vapor sorption is a powerful tool for the analysis of cement paste, one of the most used substances by mankind. The monitoring of cementitious materials is fundamental for the improvement of infrastructure resilience, which has a deep impact on the economy, the environment, and on society. In this work, a multimode fiber was embedded in cement paste for real-time monitoring of cement paste water vapor sorption. Changes in the reflected light intensity due to the build-up of water in the cement paste's pores were exploited for this purpose. The sample was 7-day moist cured, and the relative humidity was controlled between 8.9% and 97.6%. Reflected light intensity was converted into a specific surface area of cement paste (133 m(2)/g) and thickness of water through the Brunauer-Emmett-Teller (BET) method and into a pore size distribution through the Barret-Joyner-Halenda (BJH) method. The results achieved through reflected light intensity agree with those found in the literature, validating the usage of this setup for the monitoring of water vapor sorption, breaking away from standard gravimetric measurements.

2023

Spectral Analysis Methods for Improved Resolution and Sensitivity: Enhancing SPR and LSPR Optical Fiber Sensing

Authors
Dos Santos, PSS; Mendes, JP; Dias, B; Perez-Juste, J; De Almeida, JMMM; Pastoriza-Santos, I; Coelho, LCC;

Publication
SENSORS

Abstract
Biochemical-chemical sensing with plasmonic sensors is widely performed by tracking the responses of surface plasmonic resonance peaks to changes in the medium. Interestingly, consistent sensitivity and resolution improvements have been demonstrated for gold nanoparticles by analyzing other spectral features, such as spectral inflection points or peak curvatures. Nevertheless, such studies were only conducted on planar platforms and were restricted to gold nanoparticles. In this work, such methodologies are explored and expanded to plasmonic optical fibers. Thus, we study-experimentally and theoretically-the optical responses of optical fiber-doped gold or silver nanospheres and optical fibers coated with continuous gold or silver thin films. Both experimental and numerical results are analyzed with differentiation methods, using total variation regularization to effectively minimize noise amplification propagation. Consistent resolution improvements of up to 2.2x for both types of plasmonic fibers are found, demonstrating that deploying such analysis with any plasmonic optical fiber sensors can lead to sensing resolution improvements.

2023

Low-Cost Wideband Interrogation System for Fiber Optic Sensors

Authors
Araujo, JCC; dos Santos, PSS; Dias, B; de Almeida, JMMM; Coelho, LCC;

Publication
IEEE SENSORS JOURNAL

Abstract
The interrogation of optical fiber sensors (OFS) often relies on complex devices such as optical spectrum analyzers (OSAs) that are expensive with low portability and mainly suited to laboratory measurements or dedicated interrogation systems with limited spectral range. An interrogation unit was designed and fabricated using a photodetector combined with a micro-electromechanical system and a Fabry-Perot interferometer (MEMS-FPI) working as a tunable filter with a response in the range 1350-1650 nm. Deconvolution techniques were applied to mitigate the effect of the broadband response of the tunable filter on the measured signal. The performance of the unit was validated with the interrogation of long-period fiber gratings (LPFGs) as temperature, refractive index (RI), and relative humidity (RH) sensors. For the temperature, a sensitivity of 0.135 +/- 0.007 nm/degrees C was obtained, which showed a 4.9% relative error when compared to the same measurement with an OSA. For the RI, a sensitivity of 147 +/- 11 nm/RIU was obtained, which showed a relative error lower than 1% when compared to the OSA. For the humidity, sensitivities of 0.742 +/- 0.005 and 0.056 +/- 0.006 nm/%RH were obtained, with errors of 2.75% and 6.67%, respectively, when compared to a commercial dedicated interrogation system. The low relative error obtained when compared to commercial alternatives shows the potential of the system to be used in real-time applications that require portability, low cost, energy efficiency, and capacity for integration in dedicated systems.

Supervised
thesis

2022

Electromagnetic Surface Waves in One Dimensional Structures: Application to Optical Sensors

Author
Bernardo Manuel Limpo Serra dos Santos Dias

Institution
UP-FCUP

2022

Development of optical biosensors for monitoring the deterioration of fresh meat and fish

Author
Helena Catarina Araújo Soares Guedes Vasconcelos

Institution
UTAD

2022

Development of cost-effective monitoring systems for chemical water contamination using nanoparticle coated optical fibre sensors

Author
Paulo Sérgio Soares dos Santos

Institution
UP-FEUP

2022

Wireless optical fibre sensors network for the health monitoring of concrete structures

Author
Pedro Miguel Madeira da Silva

Institution

2022

Sensores em fibra ótica para a deteção de contaminantes na água

Author
José Miguel da Silva Amaral Pereira

Institution
UP-FCUP