Monday, October 7th
Advances and Perspectives Towards Tb/s Optical Transmission
Rafael C. Figueiredo, Alexandre Felipe, André Souza, Eduardo Rosa, Fábio D. Simões, Felipe Lorenzo Della Lucia, Glauco C. C. P. Simões, Giovanni de Farias, Hening Andrade, José Hélio da Cruz Júnior, Tiago Sutili, Yesica Rumaldo Bustamante, and Sandro M. Rossi
► 14:00 · Room 1 · Optical Communication 1
This paper presents recent advances on high-capacity optical fiber communication for coherent and non-coherent transmission systems. We describe works carried out at CPQD on digital signal processing, forward error correction, and integrated photonic devices for long-haul, unrepeatered, and data center interconnect scenarios. Future trends and perspectives for next generation systems based on the state-of-the-art research are also discussed.
Network Fragmentation Measure in Elastic Optical Networks
Luiz H Bonani, Majid Forghani-elahabad, and Marcelo Abbade
► 14:30 · Room 1 · Optical Communication 1
The Elastic Optical Network (EON) with multirate transmission and supported by bandwidth-variable switching technologies has provided more efficient utilization of spectral resources, leading to improvement of the network throughput. However, EON experiences a higher degree of fragmentation than conventional fixed-grid networks because of the spectrum continuity constraint and due to the dynamic nature of setup and release of the connections. In this work we propose and analyze some network fragmentation metrics, one of them applied to evaluate the spectrum fragmentation only due to the contiguity constraint.
Comparative Study of 1-Tb/s Single Laser Coherent Optical Systems based on OFDM and Nyquist FDM
André Souza, Sandro M. Rossi, and Mônica de Lacerda Rocha
► 14:50 · Room 1 · Optical Communication 1
Two multiplexing techniques, digitally frequency multiplexed Nyquist FDM and OFDM, are evaluated in high-data rate coherent optical transmissions. Simulations are carried out to achieve a net data rate of 1 Tb/s through dual-polarization 64QAM and 256QAM at 100 GBd and 75 GBd, respectively. The systems' performance were evaluated in terms of OSNR versus Tx and Rx laser linewidths, number of subcarriers, and DAC/ADC quantization and bandwidths. Despite similar performance for both techniques, CO-NFDM may allow a lower-cost implementation.
Silicon Waveguide Optically Tunable THz Filter
Gabriel Fré, Lúcia Saito, Felipe Mejía, and Danilo Spadoti
► 15:10 · Room 1 · Optical Communication 1
In this study, we present a tunable THz band pass filter design, using photo-excited low-loss slotted waveguide in a integrated CMOS compatible technology. The results show a tunable THz-filter capable of 48% of bandwidth dynamic range operation, in a spectral range from 0.55 to 0.90 THz.
Ultrafast Graphene-based Optical Modulators
Lúcia Saito, and Eunézio Thoroh de Souza
► 16:00 · Room 1 · Integrated Photonics 1
Graphene can provide solutions to integrate active and passive photonic devices on different materials platform. This paper presents a review of electro-optical modulators and recent results of graphene-based capacitive structure in optical fiber, silicon and polymer waveguides. In addition, saturable absorption properties of graphene integrated in all fiber configuration provides ultrashort pulses generation by passive mode-locking technique.
Coupled waveguides optomechanical device for the investigation of the beating force
Cauê Moreno Kersul, and Pierre-Louis de Assis
► 16:30 · Room 1 · Integrated Photonics 1
In this text we briefly present our recent efforts on detecting the beating force on coupled waveguides. The design, the fabrication and the characterization of an integrated optomechanical device with this purpose is discussed. Finally we present some preliminary results obtained with the device, demonstrating the viability of our method.
Design of near-zero GVD slow light photonic crystal waveguides
Emerson G. Melo, Thiago P. M. Alegre, Marcelo Carreño, and Marco I Alayo
► 16:50 · Room 1 · Integrated Photonics 1
Slow light propagation throughout photonic crystal slab waveguides have great potential to reduce the size and power consumption of active silicon photonic devices. A great effort has been done to understand the slow light mechanisms and their relations with the waveguide geometrical parameters. In this way, it is expected to control the waveguide dispersion characteristics and exploit the effects produced when slowing down light propagation speed, but avoiding, at the same time, the high group velocity dispersion (GVD) level drawbacks such as pulse broadening and distortion. Here, we present a concise methodology to perform an efficient near-zero GVD slow light photonic crystal waveguide oriented-design. We use a slow light flatness parameter for enabling...
Optimization of BGO Er/Yb doped pedestal waveguide amplifiers with Si nanostructures
Diego Silvério da Silva, Luciana Kassab, Niklaus Wetter, and Ernesto Jimenez-Villar
► 17:10 · Room 1 · Integrated Photonics 1
In this work we review the recent advances in pedestal waveguide amplifier fabrication. The improvement of conventional photolithography and plasma etching methods brings advantages that benefit light guiding and reduce propagation losses, mainly in the 3rd telecommunication windows (~1550 nm). Yb3+/Er3+ codoped Bi2O3-GeO2 thin films, with and without Si nanostructures, are obtained by RF Magnetron sputtering deposition and are used as core layer of 500 nm height in the pedestal waveguides. Choosing an appropriate amount of these silicon nanostructures inside the rare-earth waveguides we achieve pump light scattering and at the same time very little scattering at the signal wavelength. The overall effect is again enhancement of 50% thus opening...
Compact Laser Accelerators Towards Medical Applications - perspectives for a Brazilian Program
Nilson Vieira, Ricardo E. Samad, and Edison P Maldonado
► 14:00 · Room 2 · Optics and Instrumentation 1
Laser particle acceleration is now in a new trend due to an enormous worldwide effort to increase the peak power of femtosecond lasers, as well as increasing their average power in order to make them useful for applications. The leading example is the Extreme Light Infrastructure in Europe, which has led to the establishment of three large research facilities in the Czech Republic, Romania and Hungary that host some of the most powerful lasers world-wide (above PW peak power). This action is now being followed by the USA LaserNetUS initiative, that comprises all the big laser facilities in US, and similar efforts also happen in Asia. We are starting a program to establish a laser accelerator facility in Brazil, aiming to produce radiation (electrons,...
Performance Evaluation of the ADI-FDTD Method on the Simulation of Optical Devices
Licinius Alcantara, and Carlos Alberto De Francisco
► 14:30 · Room 2 · Optics and Instrumentation 1
This work checks the accuracy of the ADI-FDTD method for simulations of guided optical propagation regarding two optical devices: a directional coupler and a distributed Bragg reflector in a planar waveguide. The results show that despite the ADI-FDTD method is unconditionally stable as the numerical time step increases, which reduces the total time steps and the runtime compared with the conventional explicit FDTD method, its precision otherwise may decline at a level that may prevent an accurate assessment of the optical devices operational characteristics.
Sub-20 fs UV spectroscopy to track primary photoinduced processes in Thiobases
Danielle Cristina Teles Ferreira, Rocio Borrego-Varillas, Lucia Ganzer, Cristian Manzoni, Giulio Cerullo, Irene Conti, Artur Nenov, Marco Garavelli, and Ana Maria de Paula
► 14:50 · Room 2 · Optics and Instrumentation 1
Thiobases are DNA or RNA nucleobases where an exocyclic carbonyl oxygen is replaced by a sulfur atom . Thiation induces a red-shift in the absorption spectrum and causes also a dramatic change in the photophysics with respect to the canonical nucleobases: while in DNA/RNA monomers internal conversion S1→S0 mediated by a conical intersection (CI) is the main deactivation channel, the major relaxation pathway in thiobases is via the population of triplet states via an ultrafast intersystem crossing (ISC). Thiobases have attracted much interest in the last few years due to their photo-therapeutic applications . In spite of that, their ultrafast deactivation mechanisms are not yet fully understood. In this work we combine transient absorption spectroscopy...
Towards Efficient Amplified Spontaneous Emission with Engineered Colloidal Nanomaterials
Lázaro A. Padilha
► 16:00 · Room 2 · Lasers 1
Semiconductor quantum dots (QDs) present a series of optical characteristics that make them candidate for applications in lighting technologies, in particular as gain media in lasers. Among their desirable properties, we can highlight their color tunability and high emission quantum efficiencies. Here, we discuss methods of improving QD properties for lasing applications by tackling the issues of reabsorption and fast non-radiative recombination. We demonstrate that it possible to reduce the amplified spontaneous emission (ASE) threshold by engineering the multi-exction interactions in heterostructured QD, forming structures capable of combine high absorption cross section, near unity PLQY and suppressed Auger recombination. We show also that the large...
Dynamically stable continuous single frequency green ring laser
Allan Bereczki, and Niklaus Wetter
► 16:30 · Room 2 · Lasers 1
A single-frequency ring laser using two standard commercial diode-pumped Nd:YAG modules is demonstrated. Employing a dynamically stable resonator design, multi-longitudinal mode operation at 1064 nm with 53 W of output power was obtained. When inserting a LBO crystal in the resonator, 1.8 W of single-sided, single-frequency output at 532 nm was achieved. The measured linewidth was 3.6 MHz, close to the resolution limit of the scanning etalon used to measure the longitudinal mode structure.
Self-modulated laser-plasma acceleration in a H2 gas target, simulated in a spectral particle-in-cell algorithm: wakefield and electron bunch properties
Edison P Maldonado, Ricardo E. Samad, Armando V. F. Zuffi, Fabio Tabacow, and Nilson Vieira
► 16:50 · Room 2 · Lasers 1
We evaluate the results of self-modulated, laser wakefield acceleration of electrons in homogeneous, 150-μm-thick hydrogen gas target, simulated using the spectral particle-in-cell algorithm FBPIC. Considering a single 2-TW laser pulse at 800-nm, which generates ionization and plasma displacement at relativistic intensities, we discuss the resultant wakefield phases, wave-breaking, and the ejected electron bunch properties: charge, length, divergence and energy, also comparing with experimental results.
Functionalized and microstructured polymeric composites used as gain medium in random lasers systems
Adriano J. G. Otuka, Lucas F. Sciuti, Paulo H. D. Ferreira, Renato J. Martins, Cleber R. Mendonça e Leonardo de Boni
► 17:10 · Room 2 · Lasers 1
In this work, we developed optically active polymeric composite bulks which are employed as gain medium in random laser systems. To increase the number of scattering centers inside the sample, we added to the polymeric matrix single-walled carbon nanotubes. Using a laser micromachining, we fabricated periodic patterns in the volume of the composites, which allowed locking the random laser emission modes in specific wavelengths. In all performed experiments, using these different samples, we observed a coherent feedback of the random lasers.
Optical techniques as approaches for treatment of diseases and diagnostic monitoring
Jose D Vollet Filho
► 14:00 · Room 3 · Biophotonics 1
Optical techniques have been increasingly used as alternative approaches for tissue monitoring, diagnosis and treatment of diseases as different as cancer and microbiological infections. This work shall provide insight on photodynamic therapy approaches for non-melanoma skin cancer and microbiological inactivation and the use of fluorescence as a tool to monitor changes in transplanted organ grafts.
Silver and Silver-Iron Nanoparticles Synthesized by Photoreduction for Applications in Cancer Therapy
Karina Gonçalves, Fúlvio Corazza, Daniel Vieira, and Lilia Courrol
► 14:30 · Room 3 · Biophotonics 1
Metal nanoparticles have been extensively studied for various purposes including therapeutic applications for cancer. In this study, nanoparticles of silver and silver-iron with aminolevulinic acid (ALA) were synthesized using (ALA:AgNPs and ALA:AgFeNPs) the photoreduction method with a 300 W xenon lamp, characterized by UV/vis absorption, zeta potential, x-rays diffraction, FTIR and transmission electron microscopy. The sizes obtained were ~ 23 nm for silver and ~ 12 nm for iron. Cytotoxicity assays were performed on breast tumor cells (MCF-7) and prostate cancer cells (LNCaP). The results obtained showed that it was possible to synthesize silver and silver-iron nanoparticles by the photoreduction method, and to functionalize their surfaces with ALA, which...
Photodegradation in the infrared region of indocyanine green in aqueous solution
Johan Sebastián Díaz Tovar, Giulia Kassab, Natalia Inada, Vanderlei Bagnato, and Cristina Kurachi
► 14:50 · Room 3 · Biophotonics 1
Indocyanine green (ICG) is a water soluble anionic tricarbocyanine dye which has been widely used for biological applications. The photodegradation and aggregation of ICG were studied in aqueous solution by absorbance spectrum measurements. Two excitation wavelengths were used, 780 and 808 nm. The photodegradation analysis was performed based on the number of absorbed photons and rate equations of the electronic excited states. The aggregation effect is influenced by the diluent medium and also a third emission band at 640 nm, associated with PBS solution, could be observed. This new emission band is associated to a trimeric band, when ICG is diluted in PBS. The degradation of the solution with aggregated forms does not follow the Beer-Lambert law. The...
Assessment of burn wounds status using mid-infrared spectroscopy
Pedro Castro, Cassio Lima, Telma Zorn, and Denise M. Zezell
► 15:10 · Room 3 · Biophotonics 1
Burns are one of the major causes of morbidity and the most costly traumatic injuries worldwide. Better understanding of the molecular mechanisms associated with wound healing might provide improved clinical strategies to speed up the tissue repair process and reduce the global impact of burns on public health services. The traditional techniques used to assess the biochemical events related to wound repair are laborious, time-consuming and require multiple staining. Thus, the present study aims to evaluate the feasibility of Fourier transform infrared (FTIR) spectroscopy in order to monitor the progress and healing status of burn wounds. Third-degree burn injuries were induced on Wistar rats by water vapor exposure. Afterwards, biopsies specimen was...
Optical Fiber Specklegram Sensors for Measurement of Liquids
Eric Fujiwara, Thiago D Cabral, and Cristiano MB Cordeiro
► 16:00 · Room 3 · Sensors, Image and Illumination 1
Optical fiber specklegram sensors explore the spatiotemporal properties of the speckle pattern projected from a multimode fiber due to the interference between the several propagating modes. Albeit their apparent noisy nature, the speckle fields carry detailed and reproducible information about the fiber status. Specklegram changes can be analyzed to obtain very sensitive measurements with simple interrogation schemes. In this paper, different setups of fiber specklegram sensors for assessing the physical and chemical properties of liquids, such as refractive index, viscosity, and evaporation rate, are presented. The experiments are carried out using both silica multimode fibers and structured waveguides, whereas the output speckle fields are processed by...
Widely Tunable Metallic Nanorods Chain for Solar Radiation Absorption
Sajid Farooq, Renato Evangelista de Araujo, and Diego Rativa
► 16:30 · Room 3 · Sensors, Image and Illumination 1
Plasmonic nanoparticles are promising nanomaterials for solar radiation absorption harvesting due to their absorption spectral band, which can be tuned from visible to near infrared regime. In this work, the influence of metallic nanochain (Hemisperical gold nanorods linked by silica nanojunctions) on the optical properties for solar thermal collectors is investigated using 3D full -wave field analysis, based on Finite Element Method. Simulation results show that the absorption performance of gold nanorod assembly enhances by increasing the chain length. The results show that the Au chain optical extinction coefficient value is mainly determined by the absorption properties of the nanostructure. Computational modeling revealed that under solar illumination...
Bellow Useful Daylight Illuminance (BUDI): a new useful range measurement parameter
Daniela Pawelski Amaro Marinsand Cristina Alvarez, Beatriz Piderit, and Marcelo Segatto
► 16:50 · Room 3 · Sensors, Image and Illumination 1
Light plays an important role in life cycle: light is a normative issue and a common use requirement which helps the perception and apprehension of formal and conceptual aspects. Specifically, in respect to the relationship between user and light, there are intrinsic physiological and psychological issues leading to an understanding between the threshold of human comfort and discomfort. The existing methods measure light at normal state of use and location, that is, they do not usually consider an exceptional condition. In special situations, a small amount of light can be judged inadequate under standards established by regulation; however, in a situation with lack of light, that minimum amount of illuminance, can offer a positive effect. This paper is a...
Exploring Metallic Semi-Capped Nanoshells Chain for Sensing Applications
Sajid Farooq, Diego Rativa, and Renato Evangelista de Araujo
► 17:10 · Room 3 · Sensors, Image and Illumination 1
The optical properties of gold nanostructure chain, base on dielectric core/metallic semi-capped shell, have been investigated. The light-particles interactions were evaluated exploring Finite Element Method (FEM) based on full-wave field analysis in frequency domain with COMSOL Multiphysics. The simulation modeling approach focused on the assessment of the plasmonic spectral peak shift induced by environmental changes. Important parameters such as figure of merit (FoM) and refractive index sensitivity, which predict the performance of localized surface plasmon resonance (LSPR) sensor, were evaluated. Optimization of the sensor properties was obtained by tuning the semi-capped shell thickness. High values for refractive index sensitivity (RIS) and figure of...
Tuesday, October 8th
On the use of Amplification in Visible Light Communication Systems
Marcelo de Oliveira, Luis Nero Alves, Paulo P Monteiro, and Alexandre Pohl
► 16:00 · Room 1 · Optical Communication 2
Visible Light Communications (VLC) are an evolving technology that employs LED lamps to transfer data and has the potential to provide increased bandwidth in the following years. However, due to the high attenuation losses in the optical path, VLC systems generally present a short range, reaching distances not longer than a few meters. Although this may be suitable for small environments, there may be scenarios where the visible light needs to reach longer distances. In this paper, we examine the utilization of electrical and optical amplification in a relay communication link as a means to increase the link length in VLC systems
Particle Swarm Optimization for High-Order Raman Amplification Design in Unrepeatered Systems
Felipe Lorenzo Della Lucia, José Hélio da Cruz Júnior, Tiago Sutili, and Rafael C. Figueiredo
► 16:30 · Room 1 · Optical Communication 2
Particle Swarm Optimization (PSO) algorithm is applied to design high-order Raman amplifiers aiming to determine the pumping lasers wavelengths and power levels to maximize the received optical signal-to-noise ratio (OSNR) within the set-up constraints and boundary conditions. The optimum achieved OSNR was about 11.5 dB, being limited to 21 dBm of maximum propagation power along the fiber and -23.32 dBm signal power at reception. The on/off gain at the transmitter-side is found to be 18.45 dB and 27.98 dB at the receiver-side. The efficacy of the optimization algorithm is demonstrated by comparing the results obtained in this work with previously published results.
A Pedestal Waveguide Coupler for Mode Division Multiplexing
José Angel Borda-Hernández, Daniel Carvalho, Marco Isaías Chávez, and Hugo Enrique Hernandez Figueroa
► 16:50 · Room 1 · Optical Communication 2
In this work, we present a numerical design of a pedestal waveguide as a suitable alternative for coupling between few-mode fibers and integrated devices. The proposed waveguide has a cylindrical core deposited over a pedestal base. Numerical simulations are performed to show that modes propagating in pedestal waveguides possess an electric field profile similar to the LP modes in few-mode fibers. The mode coupling between these two devices can reach values up to than 96% (-0.18 dB). Besides this, the pedestal waveguide has low insertion loss (IL) and the return loss is around 8 dB. This approach is a suitable alternative in the study of multimode integrated devices in order to work alongside few-mode fibers.
All-optical Spectral Shuffling Applied to 16-QAM Signals
Melissa Oliveira Santos, Welerson Santos Souza, Thiago Bragagnolle, Leonardo Bobadilla, Ivan Aldaya, Afonso Prado, André Alves Ferreira, Luiz H Bonani, and Marcelo Abbade
► 17:10 · Room 1 · Optical Communication 2
All-optical spectral shuffling (AOSS) is a recently proposed physical layer encryption technique. In AOSS, multiple input signals are split in several spectral slices. These slices are then shuffled to form multiple encrypted signals. In fact, it is possible to transmit each shuffled signal by a different optical route. This strategy increases security because if an eavesdropper wants to detect information from a unique signal, he needs to tap at least one fiber per route. In this work, computer simulations are used to encrypt two 112 Gbps 16-quadrature amplitude modulation (QAM) signals and to propagate the shuffled signals by distinct optical routes. Our results reveal that the shuffled signals may be propagated by optical routes as long as 600 km....
High-Performance and Small Form-Factor Tunable LASERs for High-Capacity Optical Telecommunications Systems
Luís Hecker de Carvalho, Juliano Oliveira, Julio Oliveira, Giovanni de Farias, Leandro Matiolli, and Flavio Borin
► 16:00 · Room 2 · Integrated Photonics 2
In this work, an overview of requirements for compact optical modules and devices is presented, focusing on optical laser sources. Regarding coherent applications, the laser must have narrow linewidth, while, at the same time, be compact and present low power consumption, targeting C-form factor pluggable (CFP) modules. Latest results on laser development are presented, showing that the External-Cavity Laser (ECL) can fulfill the requirements for this application.
Demonstration of a low-loss and broadband Polarization Splitter-Rotator with a polysilicon waveguide in SOI platform
Giovanni de Farias, Yesica Rumaldo Bustamante, Hening Andrade, and Uiara Celine de Moura
► 16:30 · Room 2 · Integrated Photonics 2
In this work, a polarization splitter-rotator in the SOI platform is demonstrated, based on the evanescent coupling to a poly-Silicon waveguide. The device is compact (<30um), low loss (<-1.5dB) and simple to fabricate.
Saturable absorption in graphene oxide-doped acrylate polymer used for direct laser writing
Nathalia B Tomazio, Franciele Henrique, Kelly T. de Paula, Ruben D Fonseca, and Cleber R. Mendonca
► 16:50 · Room 2 · Integrated Photonics 2
Graphene oxide (GO) has gained attention in the graphene family owing to its optical and electrical properties. Besides, it is low-cost and water-soluble compared to graphene, thus holding a great potential for large-scale and cost-effective production of graphene-based materials. Several works report the 2D patterning of GO-based materials, though the fabrication of 3D micro/nanodevices based on GO is still on demand. In this work, we investigated the saturable absorption behavior of graphene oxide incorporated in an acrylate polymer, aiming at the development of microdevices to be fabricated via direct laser writing. The nonlinear measurements of such composite were carried out through the femtosecond Z-scan technique with excitation at 1550 nm. By...
Laser induced forward transfer of silver nanoparticles patterns
Luiz Eduardo Rocha, Kelly T. de Paula, and Cleber R. Mendonca
► 17:10 · Room 2 · Integrated Photonics 2
Laser-induced forward transfer (LIFT) with fs-pulses is used to produce silver nanoparticles patterns on glass substrates. LIFT is a versatile direct laser write technique in which a variety of materials can be transferred from a donor substrate to a receiver one. Here we present a study on the optimal parameters, such as scan speed and pulse energy, required to obtain a micrometric pattern on the transfer process. Spectroscopy analyses confirmed the composition and the formation of silver nanoparticles. Also, the electron microscopy image revealed a controlled and localized deposition of silver nanoparticles, indicating such approach as a promising technique for the development of applications from electronics to photonics.
Fluorescence profile of chicken meat contaminated with E. coli
Lilia Courrol, and Marcelo Vallim
► 16:00 · Room 3 · Biophotonics 2
Escherichia coli is one of the most important food-borne pathogens of public health interest worldwide. The analysis of E. coli in the food industry is both costly and time-consuming. The autofluorescence spectra of chicken meat submitted to E. coli contamination and stored at 4 °C (refrigerated) and 25 °C (at room temperature) were measured by fluorescence spectroscopy. The change of intrinsic meat fluorophores contents was studied with excitation at 340 nm, as a function of the storage time to detect the meat spoilage status. The obtained results indicate change in NADH and FAD emissions intensities mainly related to microbial metabolism, the most important process of the bacteria in food spoilage.
Use of the Modulation Transfer Function (MTF) to Aid in the Prescription of Intraocular Lenses
Rodrigo de Abreu, Luciana Salles, Davies William, and Pablo Belmonte
► 16:20 · Room 3 · Biophotonics 2
This paper presents a methodology to assist ophthalmologists on the prescription of the best lens power for a given patient, based on corneal topography exams described by Zernike polynomials. The results were analyzed based on the MTF, and the area under the MTF. It is shown that the employed methodology can provide supplemental information to analyze the visual acuity, helping in the prescription of the suitable IOL for each patient, not only based on lens power empirical formulas, but in accurate simulation data of semi custom models for each patient.
Using ultraviolet light for reduction of Staphylococcus aureus in preservation solutions for transplantation - an in vitro study
Jose D Vollet Filho, Ana Celentano Borges, Natalia Inada, Vanderlei Bagnato, and Cristina Kurachi
► 16:40 · Room 3 · Biophotonics 2
Using ultraviolet light for the microbiological control has been shown effective in literature for several applications. This study presents an in vitro investigation aimed to show the ability of ultraviolet light to reduce the colony-forming units of Staphylococcus aureus in a preservation solution used in transplantation procedures. The protocol applied produced a 3-4 log reduction.
Radiotherapy compositional and mechanical effects evaluation in radicular dentin by FTIR spectroscopy and microhardness testing
Daniela Figueredo, Matheus del Valle, Denise M. Zezell, Juliana Daguano, and Patricia da Ana
► 17:00 · Room 3 · Biophotonics 2
Head and neck cancers are responsible for 400 to 600 thousand of new cancer cases per year over the world, presenting a mortality rate of 223 to 300 thousand per year. Radiotherapy can be used as a definitive, adjuvant or palliative treatment. One of the radiotherapy indirect side effect is the radiation-related caries, characterized by presenting a painless, rampant and rapid progression. Hard tissues can be affected by the ionizing radiation, changing their composition, morphology and mechanical properties, although there is a lack of studies relating these changes with radiation caries. Thus, considering that radicular dentin is a tissue with a high incidence of radiation caries, this study aimed to evaluate the compositional and mechanical changes of...
Wednesday, October 9th
Enhancing the Delay/advance -Bandwidth Product using degenerate resonances of photonic molecules in a Silicon Photonics Platform
Michel Benite Rossi, Mário de Souza, Paulo Jarschel, and Newton C. Frateschi
► 14:00 · Room 1 · Integrated Photonics 3
We propose the use of photonic molecules, i.e., coupled silicon ring structure, for enhancing the delay-bandwidth product by using the triplet resonance for analog modulation. We design a photonic molecule, composed of a 20 um radius outer ring resonator with two 5 um radius internally coupled to it. Based on our theoretical model for this device, we find that it is impossible to advance or retard a pulse that is not fully modulated, i. e., with any residual energy in the carrier. However, for analog full modulation, when the carrier is suppressed, we predict a maximum delay/advance of 500 ps/ 250 ps, respectively, for a bandwidth of 140 GHz, with consequent product delay/advance- bandwidth of 70/35, respectively. This is by far much higher than the...
Synthesis and Characterization of MoS2/WS2 Heterostructures by Second Harmonic Generation
Pilar G Vianna, Syed Hamza Safeer, Alexandre Ore, Vanessa Gordo, Isabel C. S. Carvalho, Victor Carozo, and Christiano de Matos
► 14:20 · Room 1 · Integrated Photonics 3
Monolayers of MoS2 and WS2, as well as their vertical heterostructures, were synthesized via chemical vapor deposition. The samples were then characterized via micro-Raman and micro-photoluminescence spectroscopies, and by second harmonic generation (SHG). SHG confirms that the layers in bilayers and heterostructures grow with ~0° (or ~60°) relative twist angle. Interestingly, SHG is observed in MoS2 bilayers, indicating a deviation from the centrosymmetric 2H phase.
Modelling bolometric backaction in cavity optomechanics
André G Primo, Rodrigo Benevides, Cauê Moreno Kersul, Pierre-Louis de Assis, Gustavo Wiederhecker, and Thiago P. M. Alegre
► 14:40 · Room 1 · Integrated Photonics 3
Bolometric backaction in optomechanical cavities arises from a feedback mechanism between the device's optical, thermal and mechanical responses. From thermodynamic considerations, we derive a perturbative model for the calculation of lumped photothermal forces, generated by thermal stresses, allowing for a simple evaluation of their modification to the mechanical susceptibility in optomechanical resonators. We predict higher bolometric contribution than previous theoretical estimates, furthermore, our model enables an accurate engineering of devices where these effects can be suppressed or enhanced when compared to optomechanical backaction. Finally, we apply our description to GaAs based disk microcavities for several radii and show that for typical...
Plasmonic BaTiO3 Electro-Optic Waveguide Analysis with a Discontinuous Galerkin Method
Leandro Andrade Couto Fonseca, and Hugo Enrique Hernandez Figueroa
► 15:00 · Room 1 · Integrated Photonics 3
We have developed a novel modal solver that supports transverse anisotropic materials. The modal solver consists of the Interior Penalty Discontinuous Galerkin Method combined with a standard Finite Element Method to solve the full-wave Maxwell's curl-curl equation. Here we have used the method to analyze an anisotropic plasmonic metal-insulator-metal (MIM) waveguide. The waveguide comprises a gold-BaTiO3-gold layer that allows for a strong electro-optic effect. A simplified multiphysics approach was used to take into account the large Pockels effect in the BaTiO3 layer.
Bright and Vivid Diffractive-Plasmonic Structural Colors
Emerson G. Melo, Ana Ribeiro, Rodrigo Benevides, Antonio Zuben, Marcos Vinicius Puydinger Santos, Alexandre M. P. A. Silva, Gustavo Wiederhecker, and Thiago P. M. Alegre
► 15:20 · Room 1 · Integrated Photonics 3
Colors observed in nature can fascinate people in an extraordinary ways and are very important to form our perception of an object as well as its design. The desire to reproduce vivid colors such as those found in birds, fishes, flowers and insects has resulted in significant scientific, cultural, economic and social impacts on mankind. Among the routes to create vivid colors, structural colors based on surface plasmon resonance (SPR), which can confine the optical excitation along a metal-dielectric interface far below the diffraction limit, has attracted much attention due to its large efficiency and high spatial resolution. Also, plasmonic reflectors have been studied as an alternative image display due to the possibility of using an external light...
Power Tilt Analysis of Solutions obtained from Multi-objective Optimization of Amplifier Adaptive Control of Operating Point
Joaquim F. Martins-Filho, Carmelo Bastos-Filho, and Erick A. Barboza
► 16:00 · Room 1 · Optical Communication 3
The definition of the operating point for an optical amplifier is a problem that needs to deal with the characteristics of the amplifier and to return a solution that reaches the best quality of transmission (QoT) for the involved optical link. The definition of the gain needs to be performed autonomously, especially in dynamic optical networks. This problem is called the adaptive control of optical amplifiers operating point (ACOP). One of the most recent ACOP proposal showed that the inclusion of a variable optical attenuator (VOA) in the amplifier output can help to achieve solutions that minimize both the linear and nonlinear interference in the optical signal. This approach uses a multi-objective optimization algorithm that defines the amplifier gains...
Few-mode erbium-doped fiber amplifier design challenges for WDM optical networks
Adolfo Fernandes Herbster
► 16:30 · Room 1 · Optical Communication 3
The use of optical spatial division multiplexing (SDM) technologies increases the capacity of the optical channel, allowing higher transmission rates than those observed in wavelength division multiplexing (WDM) optical systems based on single-mode fibers. In particular, spatial multiplexing based on multimode fibers allows the transmission of information in orthogonal modes. In these systems, the erbium-doped fiber amplifier (EDFA) remains essential to compensate for optical link losses. This paper presents the challenges to the development of EDFAs for WDM optical systems based on few-mode fibers, considering the addition of gain flattening filters and correction of gain calculation.
Design of a FM-EDFA with gain correction for few-mode WDM optical networks
Adolfo Fernandes Herbster, and Murilo A Romero
► 17:00 · Room 1 · Optical Communication 3
The need to increase the capacity of modern optical communication systems requires the development of new technologies. Optical systems based on modal division multiplexing (MDM) allow an increased aggregate capacity by transmitting signals in orthogonal modes. In long-range links, however, by using EDFAs, the initially equalized WDM signal is affected by the differential signal gain (DSG), by the differential modal gain (DMG) and by the noise figure degradation due to the addition of amplified spontaneous emission (ASE) to the amplified signal. This study presents a technique that minimizes DSG and spectral gain variations in EDFAs for few-mode optical systems. The technique is applied to an FM-EDFA that amplifies a signal composed of 32 channels equally...
Measurement of Optical Materials Ablation Threshold Dependence on the Dispersion of Ultrashort Pulses
Gilberto A Rocha, Ricardo E. Samad, and Nilson Vieira
► 14:00 · Room 2 · Laser 2
The ablation threshold for ultrashort pulses of common optical materials (BK7 glass, Sapphire and Fused Silica), was measured using the D-Scan technique, for positive and negative dispersions covering pulse durations from 30 fs to 100 fs. We observed that the ablation threshold for a single shot and at saturation increase with the pulse duration and the material bandgap, and also that defects that decrease the threshold values accumulate faster as the material bandgap increases.
Production of a microfluidic random laser using ultrashort laser pulses
Wagner de Rossi, Niklaus Wetter, Antonio Gomes, and Viktor Ermakov
► 14:20 · Room 2 · Laser 2
A random rhodamine laser system is produced on board of a femtosecond laser machined microfluidic system. When pumped by a nanosecond pulsed laser beam at 532 nm, laser emission at 610 nm is observed together with the linewidth narrowing typical of random lasers. The system can be easily integrated as an optofluidic component into microfluidic circuits for assessment of optical parameters on board of the lab-on-chip.
A simulation of laser energy absorption by a nanowired surface
Alexandre Ferreira Ramos, and Miguel F. S. Vasconcelos
► 14:40 · Room 2 · Laser 2
Despite recent advances on energy release in fusion by laser inertial confinement, absorption of laser's energy by the fusion target is still low because of shielding by the plasma surface. That phenomenon prevents the laser to deeply penetrate the target and strategies to enhance the coupling between the laser-plasma would be welcome. One of such strategies is to design targets having nanowires on their surfaces that enable an increase of the laser power absorption by the targeted material. In this manuscript we present the results of simulations aiming at quantifying the increase on the absorption of laser power by nanowired surfaces.
Evaluation of the Adhesive Strength in Dentin after Irradiation with Ti:Sapphire Ultrashort Laser Pulses
Tarciso Penha Junior, Monica Rodrigues, Ricardo E. Samad, Denise M. Zezell, Nilson Vieira, and Maristela Dutra-Correa
► 15:00 · Room 2 · Laser 2
This study was done to evaluate whether the irradiation of dentine with ultrashort laser pulses prior to adhesive procedures contributes to increase the adhesive resistance to microtraction essays. Twenty-four human teeth (third molars) were used, divided into 4 groups (n=6): standard adhesive procedures with etch-rinse adhesive were used in the control group, and in the experimental groups, the dentin was irradiated by 25 fs pulses prior to the adhesive procedures, with varying fluences. One tooth from each group was used to evaluate its surface roughness. After 24h, the teeth were sectioned with perpendicular cuts, producing toothpicks that were submitted to the microtraction test. The results showed that the groups irradiated with fluences under 4 J/cm²...
Below Threshold Harmonics Dependence with Phase-Matching Parameters in Argon
Armando V. F. Zuffi, Andreia Almeida, Nilson Vieira, and Ricardo E. Samad
► 15:20 · Room 2 · Laser 2
This work reports the generation of Below Threshold Harmonics generated in Argon by ultrashort laser pulses. The 3rd, 5th, 7th and 9th harmonics of the laser were generated in the UV and VUV regions, and the frequency conversion occurred in flowing gas in a glass nozzle into a vacuum chamber. The harmonics generated show a blue-shift and an efficiency that depend on the laser pulses intensity and also on the gas pressure. These parameters determine the phase-matching condition, which governs the energy conversion from the laser into the harmonics, and this study shows that is possible to tune the harmonics intensity and wavelength, providing a versatile light source.
Photonic materials displaying direction modulated photoluminescence
Sidney JL Ribeiro, Luis Carlos, Edison Pecoraro, Fernando Maturi, Moliria Santos, and Maria Ferreira
► 16:00 · Room 2 · Optics and Instrumentation 2
The simultaneous integration of a nematic liquid crystalline structure and light emission in a photonic material is an attractive design of novel optical devices. Here we describe the luminescent study of a new optical device that integrates light emission and iridescence through a liquid crystal self-assembly of cellulose nanocrystals and silica. Freestanding composite films with chiral nematic organization were obtained and luminescent species were incorporated. The photonic structure plays the role of direction dependent inner-filter, causing selective suppression of the light emitted with angle dependent detection.
Simple FPGA Mezzanine Interface for Test and Measurement of Digital to Analog Converters
Fernando Alves Rodrigues, Guilherme Temporão, and Jean Pierrre von der Weid
► 16:20 · Room 2 · Optics and Instrumentation 2
In this work we demonstrate the experimental design and realization of a simple FPGA mezzanine interface to test and measure digital-to-analog converters. The test system can also be used (with limitations) as an arbitrary four-channel 8-bit waveform generator with fully-differential outputs. In the arbitrary waveform generator function, the system is capable to generate high order modulations for testing dual-parallel Mach-Zehnder modulators.
Measuring the nonlinear refractive index of tellurite glasses through the Z-Scan technique
André Pelosi, Jessica Dipold, Sabrina dos Santos, Juliana de Almeida, and Cleber R. Mendonca
► 16:40 · Room 2 · Optics and Instrumentation 2
A study of the nonlinear refractive index in tellurite glasses doped with two different kinds of transition metals was done. Due to the high refractive index that tellurite glasses present, the analysis is made in the telecommunication region.
Tailoring group-velocity dispersion in silica microspheres through alumina coating
Marvyn Inga, Thiago P. M. Alegre, Gustavo Wiederhecker, Yovanny Espinel, Laís Fujii, José Maria Silva Filho, Francisco C Marques, and Louise Trivizol
► 17:00 · Room 2 · Optics and Instrumentation 2
We experimentally demonstrate that alumina-coated Al2O3 silica microspheres can tuned to near-zero group-velocity dispersion and sustain ultra-high optical quality factor (>10⁷) microcavities at telecom wavelengths. Using the atomic layer deposition (ALD) technique for the Al2O3 coating, we achieve not only nm-level control of the alumina layer thickness but also a low Al2O3 surface roughness that ensures ultra-high optical quality factors. Atomic force microscopy confirms sub-5 nm RMS roughness for the ALD-deposited alumina.
Manipulating Sound with Light
G.S. Wiederecker, T.P. Mayer Alegre, G.O. Luiz, Felipe G.S. Santos, Y.A.V. Espinel, R.S. Benevides
► 17:20 · Room 2 · Optics and Instrumentation 2
The interaction between light and phonons is strongly enhanced in micro and nanoscale optical cavities and waveguides. Such enhanced interaction enabled a range of novel funcionalities based on sound-light interaction, such as generating radio-frequency signals, suppressing stimulated light scattering and probind mesoscopic phonon nodes. In this tal, I will review our recent progress in this field that relies on exploring dielectric nano-waveguides and cavities to enhance or suppress the interaction between light and mechanical waves. These techniques have recently enables probing in real-time the molecular-scale vibrational modes of carbon nanotubes.
Spectral Analysis of a Nanodipole Array above the Surface Impedance of Graphene by Green's Function
André Felipe Cruz, Tommaso Rosso, Victor Dmitriev, and Karlo Queiroz Costa
► 14:00 · Room 3 · Sensors, Image and Illumination 2
In this paper, we present a spectral analysis of a nanodipole array above a graphene layer by the Periodic Green's Function (PGF) method. The graphene layer deposited on a dielectric substrate is modeled as a surface impedance with conductivity described by the Kubo model. The Green's function is obtained by the complex two-dimensional Fourier series transform, with impedance condition at the interface between the dielectric media. We performed a parametric analysis of the influence of chemical potential on the absorbance and the electromagnetic fields in the spectral domain. For the modeling used, the dispersion characteristic of graphene is also verified. From the spectral analysis we investigated the emergence of the Surface Plasmon Polariton (SPP) pole...
Systematic comparison between photonic sensors based on dielectrics and metals
Rodrigo Romão França Soares, and Emiliano Martins
► 14:20 · Room 3 · Sensors, Image and Illumination 2
Photonic biosensors have gained much attention recently due to their high sensitivity, low energy consumption and miniaturization capability, conveying noteworthy advances in biomedicine. In the near future, these sensors will form the basis of the so-called Lab on a Chip (LoC): an equipment that would incorporate all laboratory functions into a single chip, capable of performing accurate clinical analyzes in any location, forming an important asset for countries with few resources for disease detection. There are a variety of configurations for biophotonic sensors, based on dielectric or metallic (plasmonic) media, ranging from fiber-optic based systems, waveguides, resonators, to nanoparticles and photonic crystals, to name a few. In spite of this great...
Fast Microwave-Assisted Synthesis of Green-Fluorescent Carbon Nanodots from Sugarcane Syrup
Marco C P Soares, Gabriel Perli, Júlio Bartoli, Diego Luan Bertuzzi, Thiago Bezerra Taketa, Rogério Bataglioli, Carlos Suzuki, Catia Ornelas, and Eric Fujiwara
► 14:40 · Room 3 · Sensors, Image and Illumination 2
A process for producing fluorescent Carbon Nanodots from sugarcane syrup is reported. The syrup is processed in a domestic microwave oven for 1.5 min, filtered and centrifuged, resulting in an orange stable suspension of nanoparticles capable of emitting visible (green) fluorescence when irradiated by ultraviolet (254 nm). The particles present dimensions ranging from 1 to 6 nm with distribution centered at ~5 nm, and maximum fluorescence intensity at 448 nm (violet) when excited at 360 nm. This work presents a fast and low-cost methodology for the obtention of nanoparticles with potential applications on optoelectronics, biomedicine, photocatalysis and renewable energy sources areas.
Online Monitoring of Cell Growth on PDMS-PDMS Reversible Microfluidic Bioreactor Integrated to Optical Fiber Sensor
Marco C P Soares, Franciele Vit, Lucimara de La Torre, and Eric Fujiwara
► 15:00 · Room 3 · Sensors, Image and Illumination 2
A microfluidic bioreactor was fabricated by curing PDMS over 3D-printed molds, containing two microchannels and perfusion chambers instrumented with optical fibers for the analysis of cellular growth. The channels were designed for allowing the mixture of reagents and the possibility of generation of concentration gradients, and the perfusion chambers are isolated of them by polycarbonate membranes, providing a chemical environment with a constant concentration of nutrients for the cells. The optical fibers are laterally inserted in the chambers, and the monitoring of cells concentration is based on the quasi-elastic light scattering: as the cell counting grows, there is an increase on the dispersion of the reflected intensity data, and the autocorrelation...
Polymer Based Trimodal Interferometric Sensor
Jhonattan Cordoba Ramirez, L Lechuga, Hugo Enrique Hernandez Figueroa, and Lucas H Gabrielli
► 15:20 · Room 3 · Sensors, Image and Illumination 2
In this work, a polymer-based single channel trimodal interferometric sensor is presented and demonstrated. The presented device was fabricated with Direct Laser Writer Technique at 405 nm wavelength on SU-8 photoresist, showing free spectral range of 20.2 nm and signal visibility of 5.7 dB, reaching very high sensitivity to temperature variations of 0.058 dB/◦C.
Advances in the prevention and monitoring of root dentin demineralization using lasers
Patricia da Ana, Daisa Pereira, Elizabete Ferreira, Daniela Figueredo, Juliana Daguano, and Denise M. Zezell
► 16:00 · Room 3 · Biophotonics 3
The increase in the life expectancy and the longer permanence of the teeth in the oral cavity also led to an augment in the prevalence of root caries lesions. These lesions require more attention because of their rapid progression and difficulty in early diagnosis and monitoring. In this context, the irradiation of the tissues with high intensity lasers has been shown as an important way for preventing lesion formation because lasers chemically modify the irradiated dental hard tissues and make them more resistant to acid challenge. In addition, the association with ceramic biomaterials may allow additional remineralizing results. Together with therapeutics, the effective early diagnosis of incipient lesions is indispensable. Techniques that use lasers,...
Influence of the reference spectrum used as input to the RMieS-EMSC algorithm for correction of spectral distortions induced by Mie scattering in FTIR hyperspectral images
Cassio Lima, Luciana Correa, Hugh Byrne, and Denise M. Zezell
► 16:30 · Room 3 · Biophotonics 3
Fourier transform infrared (FTIR) microspectroscopy has shown great promise as a tool to assess the histological architecture of tissue samples by providing morphochemical maps that enable the evaluation of both spatial and compositional information based on the signatures of molecular vibrations. However, FTIR datasets collected in transmission and transflection modes are subjected to undesired spectral contributions non-related to the phenomenon of light absorption that must be corrected prior any analysis. The algorithm so-called "Resonant Mie Scattering - Extended Multiplicative Scatter Correction (RMieS-EMSC)" has been well succeeded in vibrational spectroscopy in removing spectral distortions. The main idea of the algorithm is to reconstruct...
Analysis of the treatment of knee osteoarthritis using Photobiomodulation performed with a low power laser
Ana Pelosi, Salmo Silva, Alessandra Baptista, Amanda Barros, Ricardo Navarro, Livia Garcia, Martha Ribeiro, and Silvia Cristina Nunez
► 16:50 · Room 3 · Biophotonics 3
Osteoarthritis is a degenerative process that affects the joints, it begins in the articular cartilage that undergoes a process of deterioration, and may even disappear totally in a more advanced phase. The main symptoms of osteoarthritis are functional disability and pain that usually worsens with movement and improves with rest. The pain can become continuous and can lead to functional disability, which reduces the quality of life of the individual. For the treatment of knee osteoarthritis (KOA) photobiomodulation (PBM) using low power laser /LED can represents a good non-pharmacological approach. The aim of this study is to analyze the effects of PBM in the treatment of KOA. We performed a randomized prospective clinical study with an experimental and...
The Brazilian Photonics Society has begun its activities on May 24th, 2017 with the main objective to work for increasing the importance and awareness of optics and photonics in Brazil and South America.
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