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In recent years, micro and nanotechnology have undergone a rapid development due to their applications in different scientific areas such as metaphotonics, an emerging branch of optics that studies the interaction of light with micro and nanostructured metamaterials. Our particular interest is the development of integrated metaphotonic devices for lab-on-a-chip biosensing applications. A widely used technique for the manufacture of integrated optical devices is photolithography, which is based on the processing of UV-light-sensitive photoresists to create masks for the deposition of thin films and generate the desired devices. In this contribution, we present an experimental methodology for the patterning of plasmonic waveguides using a photolithography system for printing SU-8 photoresist masks on glass substrates. We show the necessary parameters to optimize the photoresist printing (beam waist, focal distance and fluence) under normal conditions and the characterization of the samples through atomic force microscopy. Due to the aspect ratio between the width of the waveguides and thickness of the photoresist, the obtained results approach us to the development of multilayered systems for new integrated metaphotonic devices.

International audience; In this contribution, we numerically demonstrate the generation of plasmonic transparency windows in the transmission spectrum of an integrated metaphotonic device. The hybrid photonic–plasmonic structure consists of two rectangular-shaped gold nanoparticles fully embedded in the core of a multimode dielectric optical waveguide, with their major axis aligned to the electric field lines of transverse electric guided modes. We show that these transparencies arise from different phenomena depending on the symmetry of the guided modes. For the TE0 mode, the quadrupolar and dipolar plasmonic resonances of the nanoparticles are weakly coupled, and the transparency window is due to the plasmonic analogue of electromagnetically induced transparency. For the TE1 mode, the quadrupolar and dipolar resonances of the nanoparticles are strongly coupled, and the transparency is originated from the classical analogue of the Autler–Townes effect. This analysis contributes to the understanding of plasmonic transparency windows, opening new perspectives in the design of on-chip devices for optical communications, sensing, and signal filtering applications.

Chip-scale integrated optical devices are one of the most developed research subjects in last years. These devices serve as a bridge to overcome size mismatch between diffraction-limited bulk optics and nanoscale photonic devices. They have been employed to develop many on-chip applications, such as integrated light sources, polarizers, optical filters, and even biosensing devices. Among these integrated systems can be found the so-called hybrid photonic-plasmonic devices, structures that integrate plasmonic metamaterials on top of optical waveguides, leading to outstanding physical phenomena. In this contribution, we present a comprehensive study of the design of hybrid photonic-plasmonic systems consisting of periodic arrays of metallic nanowires integrated on top of dielectric waveguides. Based on numerical simulations, we explain the physics of these structures and analyze light coupling between plasmonic resonances in the nanowires and the photonic modes of the waveguides below them. With this chapter we pretend to attract the interest of research community in the development of integrated hybrid photonic-plasmonic devices, especially light interaction between guided photonic modes and plasmonic resonances in metallic nanowires.

International audience; Plasmonic metalenses are optical elements that are able to shape the amplitude and the phase of light with a high spatial resolution, standing as promising elements for new low-weight imaging technologies. A desired characteristic for metalenses is to have an extended depth of focus (DOF) to bring a larger tolerance of placement of the image plane, reducing image blurring and increasing light directivity. Based on the Fresnel biprism and using the integral equation method, we numerically demonstrate light focusing with cylindrical plasmonic metalenses that are able to generate large DOF values of up to 150λ with transmission efficiencies around 50%. The easiness in the design of our plasmonic metalenses represents an advantage in terms of fabrication, opening new possibilities for the development of small-size lenses for light focusing and imaging applications.

The paper presents the results of the mathematical modelling of the haemolysis and thrombus formation process in a blood pump chamber of the pulsatile type Ventricle Assist Device system with a 30 CM3 ejection volume by using two types of the Russian national mechanical heart valves. We show the influence of the inlet valve type on the haemolysis level and the process of thrombus formation during the operation of the blood pump. Based on the obtained results, we give some recommendations on the valve type selection, which ensure a minimum haemolysis level and the minimization of stagnant zones inside the blood pump chamber.

Using wave singularities known as bound states in continuum, we report an integrated device that simultaneously generates and directs coherent beams carrying orbital angular momentum.

In this article the particularities of the dynamics study of mechatronic drives that operate at low velocities are discussed; the origins of frictional self-exited oscillations to develop an algorithm for non-linearity correction are analyzed; a drive mathematical model and the qualitative picture of the self-exited oscillations regimes were presented for the three cases: a "system with clearance and friction-free"; a system without clearance with "dry friction" and a system with clearance and "dry friction". Therefore, an algorithm to compensate the frictional self-excited oscillations based on the feedback introduction for the sliding velocity of the linear motion output link was proposed.

Coupled localized surface plasmon resonances (LSPRs) in periodic arrays of metallic nanowires are attractive for use in sensing applications due to their light enhancement and their sensitivity to the surrounding environment. Due to the interwire coupling, they behave as plasmonic waveguides with high wavevector modes that require bulky methods for efficient excitation. In this contribution, we demonstrate the excitation of coupled LSPRs in gold nanowires with photonic modes supported by an optical waveguide made with ion exchange technology. Currently, although weakly-coupled LSPRs are experimentally demonstrated, strongly-coupled LSPRs are only demonstrated numerically due to the challenge represented by the fabrication of a high density nanowire array with current electron beam lithography. Due to their operation across the visible spectrum and its low-loss coupling to standard optical fibers, integrated nanowires on glass waveguides open new perspectives for the development of hybrid photonic-plasmonic integrated optical devices.

The paper presents the results of the mathematical modelling of the thrombus formation process in the blood pump chamber of the pulsatile type Ventricle Assist Device system with a 30 cm3 ejection volume by using our national mechanical disk valve for artificial hearts. The regions with big potential thrombus formation in the blood pump chamber during the operation of the pulsatile type Ventricle Assist Device system have been determined.

The three-link mechanisms are the basis of most mechanical transmissions designed to convert the motion parameters of the input links. The general case diagram of such mechanism is examined, in order to define the possibility of obtaining three-link mechanisms able to perform the function of motion conversion at a high enough forward stroke efficiency in traction mode, and also, to ensure the mechanism self-stopping when necessary. The values of the back and forth stroke efficiency were obtained in a general form, and verified for screw-nut transmissions and screw and worm gears. The use of the obtained dependences during the mechanical transmissions design allows to determine more accurately the conditions for their operability.

Steering the beam of a wave source has been demonstrated using mechanical and non-mechanical techniques. While mechanical techniques are bulky and slow, non-mechanical techniques rely on breaking the symmetry of the refractive index profile either using asymmetric structure or injecting a non-uniform current. In this contribution, we theoretically and experimentally demonstrated a new type of topological steering of light sources in which the phase offset is provided by Floquet-Bloch phase in periodic structure. It was shown that in periodic structures, there exist singular states in the radiation region of the band diagram that exhibit diverging quality factor. Thus light sources can operate at these states with lower power threshold. The existence of these singular states are topologically protected, and their momentum are very sensitive to any small perturbations, which is used to control the steering angle. By uniformly controlling some parameters in the system, such as a physical dimension or injecting current uniformly, the beam of the light source steers. Our experimental demonstrations open new paradigm in the implementation of light steering with applications in data communications, bio imaging and sensing.

We showed that cyclotron resonance of semiconductors can be utilized in Topological devices to break the time-reversal symmetry for unidirectional propagation in THz frequency range. To demonstrate, we proposed a tunable power splitter based on topological effect.

International audience; In this contribution, we numerically study the tip enhancement of localized surface plasmons in periodic arrays of gold nanowires with triangular cross section under different illumination configurations. We found that the plasmonic resonance in a single nanowire is excited with a transverse magnetic (TM) plane wave impinging from the substrate at the critical angle, whereas grazing angles are required for the excitation of resonant propagating modes in periodic arrays of triangular-shaped nanowires. Moreover, we found that resonant plasmonic quasi-Bloch modes are efficiently excited with the fundamental TM mode of a dielectric waveguide placed underneath the array. The integrated plasmonic structure allows a strong enhancement of the electromagnetic field at the tip of the nanowires, hence its potential application in the development of new nanophotonic devices.

We demonstrated the Bound State in the Continuum Surface Emitting Laser that can steer the beam with angles depending on the topology. This novel type of the topological light source operates at room temperature.

We showed that cyclotron resonance of semiconductors can be utilized in Topological devices to break the time-reversal symmetry for unidirectional propagation in THz. To demonstrate, we proposed a tunable power splitter based on topological effect.

We demonstrated theoretically and experimentally a Bound State in the Continuum Surface Emitting Laser that operates at room temperature and it can steer the beam with an angle depending on the topology of structure.

Several works have already shown that the excitation of plasmonic structures through waveguides enables a strong light confinement and low propagation losses [1]. This kind of excitation is currently exploited in areas such as biosensing [2], nanocircuits[3] and spectroscopy[4]. The efficient excitation of surface plasmon modes (SPP) with guided modes supported by high-index-contrast waveguides, such as silicon-on-insulator waveguides, had already been shown [1,5]. However, the use of weakconfined guided modes of a glass ion exchanged waveguide as a SPP excitation source represents a technological challenge, because the mismatch between the size of their respective electromagnetic modes is so high that the resultant coupling loss is unacceptable for practical applications. In this work, we describe how an adiabatic taper structure formed by an intermediate high-index-contrast layer placed between a plasmonic structure and an ion-exchanged waveguide decreases the mismatch between effective indices, size, and shape of the guided modes. This hybrid structure concentrates the electromagnetic energy from the micrometer to the nanometer scale with low coupling losses to radiative modes. The electromagnetic mode confined to the high-index-contrast waveguide then works as an efficient source of SPP supported by metallic nanostructures placed on its surface. We theoretically studied the modal properties and field distribution along the adiabatic coupler structure. In addition, we fabricated a high-index-contrast waveguide by electron beam lithography and thermal evaporation on top of an ion-exchanged waveguide on glass. This structure was characterized with the use of near field scanning optical microscopy (NSOM). Numerical simulations were compared with the experimental results. [1] N. Djaker, R. Hostein, E. Devaux, T. W. Ebbesen, and H. Rigneault, and J. Wenger, J. Phys. Chem. C 114, 16250 (2010). [2] P. Debackere, S. Scheerlinck, P. Bienstman, R. Baets, Opt. Express 14, 7063 (2006).] [3] A. A. Reiserer, J.-S. Huang, B. Hecht, and T. Brixner. Opt. Express 18(11), 11810–11820 (2010). [4] R. Salas-Montiel, A. Apuzzo, C. Delacour, Z. Sedaghat, A. Bruyant et al. Appl. Phys Lett 100, 231109 (2012) [5] A. Apuzzo M. Fevier, M. Salas-Montiel et al. Nano letters, 13, 1000-1006

International audience

Several works have already shown that the excitation of plasmonic structures through waveguides enables a strong light confinement and low propagation losses [1]. This kind of excitation is currently exploited in areas such as biosensing [2], nanocircuits[3] and spectroscopy[4]. Efficient excitation of surface plasmon modes (SPP) with guided modes supported by high-index-contrast waveguides, such as silicon-on-insulator waveguides, had already been shown [1,5], however, the use of weak-confined guided modes of an ion exchanged waveguide on glass as a source of excitation of SPP represents a scientific and technological breakthrough. This is because the integration of plasmonic structures into low-index-contrast waveguide increases the bandwidth of operation and compatibility with conventional optical fibers. In this work, we describe how an adiabatic tapered coupler formed by an intermediate high-index-contrast layer placed between a plasmonic structure and an ion-exchanged waveguide decreases the mismatch between effective indices, size, and shape of the guided modes. This hybrid structure concentrates the electromagnetic energy from the micrometer to the nanometer scale with low coupling losses to radiative modes. The electromagnetic mode confined to the high-index-contrast waveguide then works as an efficient source of SPP supported by metallic nanostructures placed on its surface. We theoretically studied the modal properties and field distribution along the adiabatic coupler structure. In addition, we fabricated a high-index-contrast waveguide by electron beam lithography and thermal evaporation on top of an ion-exchanged waveguide on glass. This structure was characterized with the use of near field scanning optical microscopy (NSOM). Numerical simulations were compared with the experimental results. [1] N. Djaker, R. Hostein, E. Devaux, T. W. Ebbesen, and H. Rigneault, and J. Wenger, J. Phys. Chem. C 114, 16250 (2010). [2] P. Debackere, S. Scheerlinck, P. Bienstman, R. Baets, Opt. Express 14, 7063 (2006).] [3] A. A. Reiserer, J.-S. Huang, B. Hecht, and T. Brixner. Opt. Express 18(11), 11810–11820 (2010). [4] R. Salas-Montiel, A. Apuzzo, C. Delacour, Z. Sedaghat, A. Bruyant et al. Appl. Phys Lett 100, 231109 (2012) [5] A. Apuzzo M. Fevier, M. Salas-Montiel et al. Nano letters, 13, 1000-1006

Cacao (Theobroma cacao L.) represents one of the most important agricultural crops of the humid Mexican tropics. In the last 10 yr, approximately 23.000 t of this grain were no longer produced per cycle. The objective of this study was to identify characteristics and factors that restrict production in the states of Tabasco and Chiapas. A survey was applied to obtain information about 184 producers and their plantations by two-stage sampling. Descriptive statistics were calculated and multilevel models were adjusted to analyze the information. Results show that there are differences (P < 0.05) in cacao yield between municipalities (380 kg ha-1 + u,o j is the estimated residual for each municipality). Crop productivity levels are higher in the state of Tabasco than in Chiapas (644 and 344 kg ha-1, respectively). Incidence of frosty pod rot of cacoa, also known as moniliasis, induced by Moniliophthora roreri [(Cif) H.C. Evans, Stalpers, Samson & Benny 1978] is significantly greater (P < 0.05) in the state of Chiapas (60%) than in Tabasco (48%).Producers who carry out more crop management practices increase yields and decrease the pathogen’s impact on their plantations. Results suggest the need to apply differentiated public policies to promote production within each region or municipality.

We describe a case in which a discrete atretic segment of the right pulmonary artery (due to a Blalock-Taussig shunt) was reconstructed using a new radiofrequency system, balloon dilation, and stent implantation in an 18-month-old patient. The shunt was coil-occluded. The technique and applications of this novel approach are discussed.

International audience; The eigenmodes analysis of Bloch modes in a chain of metallic nanowires (MNWs) provides a significant physical understanding about the light propagation phenomena involved in such structures. However, most of these analyses have been done above the light line in the dispersion relation, where the Bloch modes can only be excited with radiative modes. By making use of the Fourier modal method, in this paper we rigorously calculate the eigenmode and mode excitation of a chain of MNWs via the fundamental transverse magnetic (TM) mode of a dielectric waveguide. Quadrupolar and dipolar transversal Bloch modes were obtained in an MNW chain embedded in a dielectric material. These modes can be coupled efficiently with the fundamental TM mode of the waveguide. Since the eigenmodes supported by the integrated plasmonic structure exhibit strong localized surface plasmon (LSP) resonances, they could serve as a nanodevice for sensing applications. Also, the analysis opens a direction for novel nanostructures, potentially helpful for the efficient excitation of LSPs and strong field enhancement.

International audience; Integrated optical devices able to control light–matter interactions on the nanoscale have attracted the attention of the scientific community in recent years. However, most of these devices are based on silicon waveguides, limiting their use for telecommunication wavelengths. In this contribution, we propose an integrated device that operates with light in the visible spectrum. The proposed device is a hybrid structure consisting of a high-refractive-index layer placed on top of an ion-exchanged glass waveguide. We demonstrate that this hybrid structure serves as an efficient light coupler for the excitation of nanoemitters. The numerical and experimental results show that the device can enhance the electromagnetic field confinement up to 11 times, allowing a higher photoluminescence signal from nanocrystals placed on its surface. The designed device opens new perspectives in the generation of new optical devices suitable for quantum information or for optical sensing.

International audience; Light propagation in an integrated chain of metallic nanowires (MNW) is theoretically investigated by means of rigorous coupled wave analysis. First, we analyze the nanowires chain immersed in a dielectric homogeneous medium and we compute the eigenmodes dispersion relation and their field profiles. Depending on the nanowire aspect ratio, in addition to the longitudinal and the transversal chain modes, we found a new mode characterized by quadrupolar-like localized surface plasmons resonances well identified at the edge of the first Brillouin zone. We then consider the vertical coupling of the MNW chain with the fundamental TM0 mode of a planar dielectric waveguide. We demonstrate that high energy transfer can be obtained, by computing near field maps and spectral responses (transmission, reflection, and absorption) of the structure consisting in a finite number of nanowires. The coupling mechanism between the dielectric waveguide and the MNW chain is rigorously explained through the analysis of the eigenmodes dispersion relation.

Topological Insulator-based devices can transport electrons/photons at the surfaces of materials without any back reflections, even in the presence of obstacles. Topological properties have recently been studied using non-reciprocal materials such as gyromagnetics or using bianisotropy. However, these effects usually saturate at optical frequencies and limit our ability to scale down devices. In order to implement topological devices that we introduce in this paper for the terahertz range, we show that semiconductors can be utilized via their cyclotron resonance in combination with small magnetic fields. We propose novel terahertz operating devices such as the topological tunable power splitter and the topological circulator. This work opens new perspectives in the design of terahertz integrated devices and circuits with high functionality.

Recent studies have demonstrated that nano-patch antennas formed by metallic nanocubes placed on top of a metallic film largely enhance the spontaneous emission rate of quantum emitters due to the confinement of the electromagnetic field in the small nanogap cavity. The popularity of this architecture is, in part, due to the ease in fabrication. In this contribution, we theoretically demonstrate that a dimer formed by two metallic nanocubes embedded in a dielectric medium exhibits enhanced emission rate compared to the nano-patch antenna. Furthermore, we compare the directivity and radiation efficiency of both nanoantennas. From these characteristics, we obtained information about the “material efficiency” and the coupling mismatch efficiency between a dipole emitter and the nanoantenna. These quantities provide a more intuitive insight than the Purcell factor or localized density of states, opening new perspectives in nanoantenna design for ultra-directive light emission.

Using numerical simulations, we demonstrate that the dipolar plasmonic resonance of a single metallic nanoparticle inserted in the core of a dielectric waveguide can be excited with higher order photonic modes of the waveguide only if their symmetry is compatible with the charge distribution of the plasmonic mode. For the case of a symmetric waveguide, we demonstrate that this condition is only achieved if the particle is shifted from the center of the core. The simple and comprehensive analysis presented in this contribution will serve as basis for applications in integrated nanophotonic/metamaterials devices, such as optical filters, modulators and mode converters.

The present paper shows an optical interferometer which operates only in the geometric phase, or Berry's phase. In this system, the optical paths traversed by the two beams of light are always the same, and the difference in their phases can be varied by manipulating this geometrical phase. We also make a comparison of the interference pattern produced experimentally in the laboratory, and another one produced by a computer program.

Rio Ceibas is a freshwater shaly reservoir in the Honda formation of Colombia. A typical well has 15+ sands, which may contain light oil, medium oil or mobile water. Formation evaluation is difficult. The fresh water and the high volume of smectite clay cause resistivity logs to respond more to the volume of clay than to the difference between oil and water. Nuclear measurements do not indicate clearly the most productive intervals. A focused effort was started in 1998 to increase production using cost-effective modern technology, one element of which was the introduction of nuclear magnetic resonance (NMR) logs. At the wellsite, NMR permeability is used to choose points for wireline pressure tests. The percentage of dry tests has been reduced from 24% to 7%. This saves significant rig time since pressures must be monitored regularly in many sands. As verified on cores, the presence of an NMR signal with T2 > 300ms is a sign of light hydrocarbons. When other data are inconclusive, this indicator helps to decide whether to perforate a sand. NMR free fluid and permeability are then used to decide which intervals in the sands have the best producibility. This method saves costs by reducing perforating intervals without reducing production. For reservoir description, NMR has contributed to improved estimates of effective porosity, and qualitative permeability. Both cores and logs have been analyzed to establish interpretation parameters such as bound- and clay- water cutoffs, and permeability coefficients. In those sands that produce clean oil, the irreducible water from NMR logs is an indicator of water saturation, because of the difficulty of obtaining a reliable value from conventional logs. It is also used to determine resistivity interpretation parameters for calculations in other sands. The new formation evaluation procedure improves the match between predicted and actual production.