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
Download Photo HD

About

O. Frazão, Graduated in Physics Engineering (optoelectronics and electronics) from the University of Aveiro, Portugal. He received the Ph. D. degree in Physics from the University of Porto, Portugal in 2009. Portugal. From 1997 to 1998, he was with the Institute of Telecommunications, Aveiro. Presently, he is a Researcher at Optoelectronics and Electronic Systems Unit, INESC Porto. He has published about 200 papers, mainly in international journals and conference proceedings, and his present research interests included optical fiber sensors and optical communications. He is member of the Optical Society of America (OSA) and The International Society for Optical Engineering (SPIE).

Interest
Topics
Details

Details

  • Nationality

    Portugal
  • Centre

    Applied Photonics
  • Contacts

    +351220402301
    orlando.frazao@inesctec.pt
011
Publications

2021

Nano-Displacement Measurement Using an Optical Drop-Shaped Structure

Authors
Robalinho, P; Frazao, O;

Publication
IEEE Photonics Technology Letters

Abstract

2021

Colossal enhancement of strain sensitivity using the push-pull deformation method

Authors
Robalinho, P; Gomes, A; Frazao, O;

Publication
IEEE Sensors Journal

Abstract

2021

Experimental investigation of a strain gauge sensor based on Fiber Bragg Grating for diameter measurement

Authors
Cardoso, VHR; Caldas, P; Giraldi, MTR; Frazao, O; de Carvalho, CJR; Costa, JCWA; Santos, JL;

Publication
Optical Fiber Technology

Abstract
A strain gauge sensor based on Fiber Bragg Grating (FBG) for diameter measurement is proposed and experimentally demonstrated. The sensor is easily fabricated inserting the FBG on the strain gauge—it was fabricated using a 3D printer—and fixing the FBG in two points of this structure. The idea is to vary the diameter of the structure. We developed two experimental setups, the first one is used to evaluate the response of the FBG to strain and the second one to assess the possibility of using the structure developed to monitor the desired parameter. The results demonstrated that the structure can be used as a way to monitor the diameter variation in some applications. The sensor presented a sensitivity of 0.5361 nm/mm and a good linear response of 0.9976 using the Strain Gauge with FBG and fused taper. © 2020 Elsevier Inc.

2021

Giant Displacement Sensitivity Using Push-Pull Method in Interferometry

Authors
Robalinho, P; Frazao, O;

Publication
Photonics

Abstract
We present a giant sensitivity displacement sensor combining the push-pull method and enhanced Vernier effect. The displacement sensor consists in two interferometers that are composed by two cleaved standard optical fibers coupled by a 3 dB coupler and combined with a double-sided mirror. The push pull-method is applied to the mirror creating a symmetrical change to the length of each interferometer. Furthermore, we demonstrate that the Vernier effect has a maximum sensitivity of two-fold that obtained with a single interferometer. The combination of the push-pull method and the Vernier effect in the displacement sensors allows a sensitivity of 60 ± 1 nm/µm when compared with a single interferometer working in the same free spectral range. In addition, exploring the maximum performance of the displacement sensors, a sensitivity of 254 ± 6 nm/µm is achieved, presenting a M-factor of 1071 and MVernier of 1.9 corresponding to a resolution of 79 pm. This new solution allows the implementation of giant-sensitive displacement measurement for a wide range of applications.

2021

Thermally Stimulated Desorption Optical Fiber-Based Interrogation System: An Analysis of Graphene Oxide Layers’ Stability

Authors
Raposo, M; Xavier, C; Monteiro, C; Silva, S; Frazao, O; Zagalo, P; Ribeiro, PA;

Publication
Photonics

Abstract
Thin graphene oxide (GO) film layers are being widely used as sensing layers in different types of electrical and optical sensor devices. GO layers are particularly popular because of their tuned interface reflectivity. The stability of GO layers is fundamental for sensor device reliability, particularly in complex aqueous environments such as wastewater. In this work, the stability of GO layers in layer-by-layer (LbL) films of polyethyleneimine (PEI) and GO was investigated. The results led to the following conclusions: PEI/GO films grow linearly with the number of bilayers as long as the adsorption time is kept constant; the adsorption kinetics of a GO layer follow the behavior of the adsorption of polyelectrolytes; and the interaction associated with the growth of these films is of the ionic type since the desorption activation energy has a value of 119 ± 17 kJ/mol. Therefore, it is possible to conclude that PEI/GO films are suitable for application in optical fiber sensor devices; most importantly, an optical fiber-based interrogation setup can easily be adapted to investigate in situ desorption via a thermally stimulated process. In addition, it is possible to draw inferences about film stability in solution in a fast, reliable way when compared with the traditional ones.

Supervised
thesis

2020

Estudo e desenvolvimento de novas configurações de sensores em fibra ótica para monitorização de cristalizadores na área farmacêutica

Author
Liliana Patrícia Santos Soares

Institution
INESCTEC

2020

Raman Endoscopy Using Optical Fiber Technology

Author
João Pedro Marques

Institution
INESCTEC

2020

Optical Fiber Nanowires: Fabrication and Sensing Applications

Author
André Rodrigues Delgado Coelho Gomes

Institution
INESCTEC

2019

Raman Spectroscopy in tumoral tissues

Author
João Manuel Ribeiro Jordão

Institution
INESCTEC

2019

Surface plasmon resonance excitations and nonlinear phenomena in light-guiding structures based on tapered optical fibers

Author
Tiago Jorge Mendes Martins

Institution
INESCTEC