Joana Tavares

Dr. Joana Tavares

CTM, INESC TEC, Institute for Systems and Computer Engineering, Technology and Science, Porto, Portugal
+2
orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 July 2014 in Optics Express
Verified
Journal Article
Closed access
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LPLuis M. Pessoa
Luis M. Pessoa
JTJoana Tavares
Joana Tavares
DCDiogo Coelho
Diogo Coelho
Henrique M. SalgadoHenrique M. Salgado
Henrique M. Salgado
Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings from OSA conferences.

16 January 2019 in Microwave and Optical Technology Letters
Verified
Journal Article
Open access
PDF file
Scott WatsonScott Watson
Scott Watson
WZWeikang Zhang
Weikang Zhang
JTJoana Tavares
Joana Tavares
JFJosé M. L. Figueiredo
José M. L. Figueiredo
HCHoracio Cantu
Horacio Cantu
AKAnthony Kelly
Anthony Kelly
Optical modulation characteristics of resonant tunneling diode photodetectors (RTD‐PD) are investigated. Intensity modulated light excites the RTD‐PDs to conduct data experiments. Simple and complex data patterns are used with results showing data rates up to 80 and 200 Mbit/s, respectively. This is the first demonstration of complex modulation using resonant tunneling diodes.

13 July 2017 in Journal of Lightwave Technology
Verified
Journal Article
Closed access
JTJoana Tavares
Joana Tavares
LPLuis M. Pessoa
Luis M. Pessoa
Henrique M. SalgadoHenrique M. Salgado
Henrique M. Salgado
In this paper, we further explore the concept of phase-conjugated twin waves (PCTW) for nonlinear cancellation in space-division multiplexed (SDM) systems. Previously, we demonstrated that the PCTW technique can successfully provide nonlinear cancellation in SDM systems. In this paper, we investigate the cases where two and four spatial modes are copropagating in a multimode fiber, considering three link lengths (1000, 3200, and 8000 km). Weak- and strong-coupling regimes are also evaluated. Our numerical simulation results show an average performance improvement >10 dB after a 1000 km transmission link.

31 May 2019 in Optics Express
Verified
Journal Article
Open access
PDF file
WZWeikang Zhang
Weikang Zhang
Scott WatsonScott Watson
Scott Watson
JFJosé M. L. Figueiredo
José M. L. Figueiredo
JWJue Wang
Jue Wang
HCHoracio I. Cantú
Horacio I. Cantú
AKAnthony E. Kelly
Anthony E. Kelly
We report on the direct intensity modulation characteristics of a high-speed resonant tunneling diode-photodetector (RTD-PD) with an oscillation frequency of 79 GHz. This work demonstrates both electrical and optical modulation and shows that RTD-PD oscillators can be utilized as versatile optoelectronic/radio interfaces. This is the first demonstration of optical modulation of an RF carrier using integrated RTD-PD oscillators at microwave frequencies.

1 July 2017
Verified
Conference Paper
Closed access
JTJoana Tavares
Joana Tavares
LPLuis M. Pessoa
Luis M. Pessoa
JFJosé M. L. Figueiredo
José M. L. Figueiredo
Henrique M. SalgadoHenrique M. Salgado
Henrique M. Salgado
In this paper, we investigate the optical modulation characteristics of a resonant tunnelling diode (RTD) oscillator. This preliminary work on the first RTD-PD oscillators with an optical window available from the iBROW project demonstrate that this device can effectively be used to accomplish amplitude and frequency modulation with light injection.

29 December 2022 in Sensors
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Journal Article
Open access
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JAJoão Henrique Araújo
João Henrique Araújo
JTJoana Tavares
Joana Tavares
VMVeridiano M. Marques
Veridiano M. Marques
Henrique M. SalgadoHenrique M. Salgado
Henrique M. Salgado
LPLuis M. Pessoa
Luis M. Pessoa
This paper proposes a multiple-lens receiver scheme to increase the misalignment tolerance of an underwater optical wireless communications link between an autonomous underwater vehicle (AUV) and a sensor plane. An accurate model of photon propagation based on the Monte Carlo simulation is presented which accounts for the lens(es) photon refraction at the sensor interface and angular misalignment between the emitter and receiver. The results show that the ideal divergence of the beam of the emitter is around 15° for a 1 m transmission length, increasing to 22° for a shorter distance of 0.5 m but being independent of the water turbidity. In addition, it is concluded that a seven-lense scheme is approximately three times more tolerant to offset than a single lens. A random forest machine learning algorithm is also assessed for its suitability to estimate the offset and angle of the AUV in relation to the fixed sensor, based on the power distribution of each lens, in real time. The algorithm is able to estimate the offset and angular misalignment with a mean square error of 5 mm (6 mm) and 0.157 rad (0.174 rad) for a distance between the transmitter and receiver of 1 m and 0.5 m, respectively.