Mário Lima

Bio: Mário Lima is an academic researcher from University of Aveiro. The author has contributed to research in topics: Wavelength-division multiplexing & Optical performance monitoring. The author has an hindex of 14, co-authored 162 publications receiving 780 citations. Previous affiliations of Mário Lima include University of Minho.

Terabit+ (192 × 10 Gb/s) Nyquist shaped UDWDM coherent PON with upstream and downstream over a 12.8 nm band

Abstract: We experimentally demonstrate a bi-directional Terabit+ UDWDM coherent PON with Nyquist shaped 16QAM modulation, offering up to 10 Gb/s service capabilities per user/wavelength in a total spectrum of 12.8 nm over 40 km of SSMF.

Terabit+ (192 × 10 Gb/s) Nyquist Shaped UDWDM Coherent PON With Upstream and Downstream Over a 12.8 nm Band

Abstract: In this paper, we numerically and experimentally demonstrate a bidirectional Terabit+ ultradense wavelength-division multiplexing (UDWDM) coherent passive optical network with Nyquist shaped 16-ary quadrature amplitude modulation, offering up to 10 Gb/s service capabilities per user/wavelength in a total spectrum of 12.8 nm over 40 km of standard single-mode fiber. This paper first demonstrates the capability of Nyquist pulse shaping to mitigate crosstalk arising from back-reflections and nonlinear effects in UDWDM networks with coherent transceivers. The latter part of the paper experimentally investigates the bidirectional transmission in terms of receiver sensitivity and nonlinear tolerance under different network transmission capacity conditions, e.g., number of users and bit rate per users.

Simultaneous measurement of strain and temperature using type I and type IIA fibre Bragg gratings

Abstract: We present a fibre optic sensing head for making simultaneous measurements of temperature and strain, which operates over a large temperature range. The configuration is based on the different temperature sensitivities of type I and type IIA gratings written in a fibre with high germanium content. Maximal errors of ± 0.7°C Hz−1/2 and ±3.8 µe Hz−1/2 are reported over 500°C and 1200 µe measurement ranges, respectively.

Ultra High Capacity Self-Homodyne PON With Simplified ONU and Burst-Mode Upstream

Abstract: In this letter, we demonstrate a proof of concept fully loaded bidirectional ultrahigh capacity coherent passive optical network (2 × 1008 × 8.3 Gb/s). This was achieved using partial spectrum overlap, Nyquist shaping, digital frequency shifting, self-homodyne detection, and pilot tone remodulation. Upstream burst mode operation is also demonstrated.

Integrated Optical Mach-Zehnder Interferometer Based on Organic-Inorganic Hybrids for Photonics-on-a-Chip Biosensing Applications.

Abstract: The development of portable low-cost integrated optics-based biosensors for photonics-on-a-chip devices for real-time diagnosis are of great interest, offering significant advantages over current analytical methods. We report the fabrication and characterization of an optical sensor based on a Mach-Zehnder interferometer to monitor the growing concentration of bacteria in a liquid medium. The device pattern was imprinted on transparent self-patternable organic-inorganic di-ureasil hybrid films by direct UV-laser, reducing the complexity and cost production compared with lithographic techniques or three-dimensional (3D) patterning using femtosecond lasers. The sensor performance was evaluated using, as an illustrative example, E. coli cell growth in an aqueous medium. The measured sensitivity (2 × 10−4 RIU) and limit of detection (LOD = 2 × 10−4) are among the best values known for low-refractive index contrast sensors. Furthermore, the di-ureasil hybrid used to produce this biosensor has additional advantages, such as mechanical flexibility, thermal stability, and low insertion losses due to fiber-device refractive index mismatch (~1.49). Therefore, the proposed sensor constitutes a direct, compact, fast, and cost-effective solution for monitoring the concentration of lived-cells.

Microwave Photonics

Abstract: Broadband and low loss capability of photonics has led to an ever-increasing interest in its use for the generation, processing, control and distribution of microwave and millimeter-wave signals for applications such as broadband wireless access networks, sensor networks, radar, satellite communitarians, instrumentation and warfare systems. In this tutorial, techniques developed in the last few years in microwave photonics are reviewed with an emphasis on the systems architectures for photonic generation and processing of microwave signals, photonic true-time delay beamforming, radio-over-fiber systems, and photonic analog-to-digital conversion. Challenges in system implementation for practical applications and new areas of research in microwave photonics are also discussed.

Microwave photonics

Abstract: Microwave photonics is an area that studies the generation, processing, control and transmission of microwave signals by means of photonics. In this paper, microwave photonics techniques developed in the past few years will be reviewed, with an emphasis on system architectures for microwave applications.

Fiber-Wireless Networks and Subsystem Technologies

Abstract: Hybrid fiber-wireless networks incorporating WDM technology for fixed wireless access operating in the sub-millimeter-wave and millimeter-wave (mm-wave) frequency regions are being actively pursued to provide untethered connectivity for ultrahigh bandwidth communications. The architecture of such radio networks requires a large number of antenna base-stations with high throughput to be deployed to maximize the geographical coverage with the main switching and routing functionalities located in a centralized location. The transportation of mm-wave wireless signals within the hybrid network is subject to several impairments including low opto-electronic conversion efficiency, fiber chromatic dispersion and also degradation due to nonlinearities along the link. One of the major technical challenges in implementing such networks lies in the mitigation of these various optical impairments that the wireless signals experience within the hybrid network. In this paper, we present an overview of different techniques to optically transport mm-wave wireless signals and to overcome impairments associated with the transport of the wireless signals. We also review the different designs of subsystems for integrating fiber-wireless technology onto existing optical infrastructure.

Physical Biology of the Cell

Abstract: Physical Biology of the Cell, 2nd Edition, is a textbook that focuses on the application of physical principles to understanding biological systems. The subject matter of the text is organized according to common physical principles that govern biological processes rather than in relation to the biological processes themselves, as is common for most biology and cell biology textbooks. Topics covered in the book span a broad range of interests, including electrostatics, molecular interactions, molecular motors and the cytoskeleton, and membranes. Each chapter features color figures, derived equations with relevant examples, and problem sets at the chapter’s conclusion. The problem sets at the end of the chapters are expanded from the first edition. Further, the second edition includes two new chapters, one on light and pattern formation, and another on the use of computation in exploring biological problems. Additional student and instructor resources are also available online. The primary audience for the textbook could include advanced undergraduate students or first-year graduate students. While the textbook may be best suited for a biophysics course, it could also be used as a primary or supplementary text for teaching cellular and molecular biology. As a teaching tool for cellular and molecular biology, the many examples featured throughout the text could easily be employed to assist students in learning the principles of how a cellular or molecular system functions. A basic level of mathematical proficiency would be required of the student. While this textbook could be an excellent resource for many courses, there are several topics commonly covered in biochemistry classes, such the glycolytic pathway, that are featured in the book but in different contexts than many widely used biochemistry texts. For a biophysics course that is heavily focused on techniques, individual references that discuss the specific techniques in detail would be more suitable than this book. Of course, any instructor seeking to use this textbook should be aware of its content before making a selection. This textbook is an excellent resource, both for a research scientist and for a teacher. The authors do a superb job of selecting the material for each chapter and explaining the material with equations and narrative in an easily digestible manner. Readers who enjoy this book may also enjoy Molecular Driving Forces by Dill and Bromberg, which gives excellent treatment of similar concepts.

Optical performance monitoring

Abstract: Progress in optical networking has stimulated interest in optical performance monitoring (OPM), particularly regarding signal quality measures such as optical signal-to-noise ratio (SNR), Q-factor, and dispersion. These advanced monitoring methods have the potential to extend fault management and quality-of-service (QoS) monitoring into the optical domain. This paper reviews OPM applications and techniques, while examining the role of OPM as an enabling technology for advances in high-speed and optically switched networks.