Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
About

About

I have received my master’s degree in Physical Engineering from the Faculty of Sciences of University of Porto (FCUP) in October 2016. My master thesis, “Optical Sensors Based on Fabry-Perot Interferometry”, was conducted in collaboration between FCUP and INESC-TEC, at the Center of Applied Photonics (CAP).

I have worked at Centre for Information Systems and Computer Graphics (CSIG), participating in a research project to develop optical fiber sensors for radon detection in marine environments.

I am currently a PhD student at CAP.

Interest
Topics
Details

Details

  • Name

    Catarina Silva Monteiro
  • Role

    Assistant Researcher
  • Since

    01st September 2015
  • Nationality

    Portugal
  • Centre

    Applied Photonics
  • Contacts

    +351220402301
    catarina.s.monteiro@inesctec.pt
002
Publications

2024

Enhanced Sensitivity in Optical Sensors through Self-Image Theory and Graphene Oxide Coating

Authors
Cunha, C; Monteiro, C; Vaz, A; Silva, S; Frazao, O; Novais, S;

Publication
SENSORS

Abstract
This paper presents an approach to enhancing sensitivity in optical sensors by integrating self-image theory and graphene oxide coating. The sensor is specifically engineered to quantitatively assess glucose concentrations in aqueous solutions that simulate the spectrum of glucose levels typically encountered in human saliva. Prior to sensor fabrication, the theoretical self-image points were rigorously validated using Multiphysics COMSOL 6.0 software. Subsequently, the sensor was fabricated to a length corresponding to the second self-image point (29.12 mm) and coated with an 80 mu m/mL graphene oxide film using the Layer-by-Layer technique. The sensor characterization in refractive index demonstrated a wavelength sensitivity of 200 +/- 6 nm/RIU. Comparative evaluations of uncoated and graphene oxide-coated sensors applied to measure glucose in solutions ranging from 25 to 200 mg/dL showed an eightfold sensitivity improvement with one bilayer of Polyethyleneimine/graphene. The final graphene oxide-based sensor exhibited a sensitivity of 10.403 +/- 0.004 pm/(mg/dL) and demonstrated stability with a low standard deviation of 0.46 pm/min and a maximum theoretical resolution of 1.90 mg/dL.

2023

Transmissive glucose concentration plasmonic Au sensor based on unclad optical fiber

Authors
Cunha, C; Assuncao, AS; Monteiro, CS; Leitao, C; Mendes, JP; Silva, S; Frazao, O; Novais, S;

Publication
2023 IEEE 7TH PORTUGUESE MEETING ON BIOENGINEERING, ENBENG

Abstract
Using surface resonance (SPR) as a sensitivity enhancer, this work describes the development of a transmissive multimode optical fiber sensor with a gold (Au) thin film that measures glucose concentration. The fiber's cladding was initially removed, and an Au layer was then sputtered onto its surface to simultaneously excite SPR and reflect light, making the SPR sensor extremely sensitive to changes in the environment's refractive index. A range of glucose concentrations, from 0.0001 to 0.5000 g/ml, were tested on the sensor. A maximum sensitivity of 161.302 nm/(g/mL) was attained for the lowest glucose concentration, while the highest concentration yielded a sensitivity of 312.000 nm/(g/mL). The proposed sensor's compact size, high sensitivity, good stability and practicality make it a promising candidate for a range of applications, including detecting diabetes.

2023

Short Pulse Generation in Erbium-Doped Fiber Lasers Using Graphene Oxide as a Saturable Absorber

Authors
Monteiro, S; Herrera, P; Silva, S; Frazão, O;

Publication
International Conference on Photonics, Optics and Laser Technology

Abstract
The use of graphene oxide (GO) as a saturable absorber for short pulses generation in an Erbium-doped fiber laser was studied and demonstrated. The saturable absorber consisted of a thin GO film, with a high concentration of monolayer GO flakes, spray-coated on the end face of a ferrule-connected fiber. By including the saturable absorber in the laser cavity and controlling the intra-cavity polarization, the generation of shortpulsed light was achieved under mode-locking and Q-switching operations. Under mode-locking operation, it was observed a pulse train with a fundamental repetition rate of 1.48 MHz, with a working wavelength centered at 1564.4 nm. In the Q-switch operation, a pulse train with a 12.7 kHz repetition rate and a 14.3 µs pulse duration was attained for a 230-mA pump current. Further investigation showed a linear dependence of the repetition rate with the pump power, attaining frequencies between 12.7 and 14.4 kHz. © 2023 by SCITEPRESS - Science and Technology Publications, Lda.

2023

How to Use Fiber Optic Sensors for Accurate Absolute Measurements - INVITED

Authors
Frazão, O; Robalinho, P; Vaz, A; Soares, L; Soares, B; Monteiro, C; Novais, S; Silva, S;

Publication
EPJ Web of Conferences

Abstract
The scientific community has been exploring new concepts as a result of the usage of optical fibers as absolute measurement sensors. While cross-sensitivity is a common issue with optical fiber sensors, this issue has been mitigated by simultaneous measurement techniques. But when it comes to absolute measurements, these methods have some limitations. The white light interferometer, which offers a superb solution for a range of applications, especially for absolute temperature measurement, is one of the most often used methods for absolute measurements.

2023

Optical fiber flowmeter based on graphene oxide coated michelson interferometer

Authors
Monteiro, CS; Ferreira, M; Mendes, JP; Coelho, LCC; Silva, SO; Frazao, O;

Publication
SENSORS AND ACTUATORS A-PHYSICAL

Abstract
Measuring gas and liquid flow rate is paramount in various scientific and industrial applications. This work presents an optical fiber flowmeter based on a graphene oxide (GO) coated Michelson interferometer. The interferometer is fabricated using a long-period fiber grating (LPFG) followed by a GO-coated single-mode fiber (SMF). By radiating the GO coating, it experiences photothermic effect that induces local heating of the film. This results in a variation in the effective refractive index in the cladding modes, which induces a phase shift on the interferometer spectrum. When a gas flow is introduced near the coated fiber, the hot-wire region will experience a reduction in temperature proportional to the flow rate. The flowmeter exhibited a linear wavelength shift to the flow rate with an absolute sensitivity of 17.4 +/- 0.8 pm/(L.min-1) for gas flow rates between 2 and 8 L/ min. Furthermore, the dynamic response of the sensor was studied, attaining a maximum response time of 1.1 +/- 0.4 s