Showing papers on "Splitter published in 2017"
TL;DR: In this paper, a microwave microfluidic sensor for dielectric characterization of liquids in real time is presented, which is implemented in microstrip technology and consists of a symmetric splitter/combiner configuration loaded with a pair of identical split ring resonators (SRRs) and micro fluid channels placed on top of them (gap region).
Abstract: A microwave microfluidic sensor for dielectric characterization of liquids in real time is presented in this paper. The sensor is implemented in microstrip technology and consists of a symmetric splitter/combiner configuration loaded with a pair of identical split ring resonators (SRRs) and microfluidic channels placed on top of them (gap region). The sensor works in differential mode and sensing is based on frequency splitting. Thus, if the structure is unloaded or if it is symmetrically loaded with regard to the axial plane, only one transmission zero (notch) in the frequency response appears. However, if the axial symmetry is disrupted (e.g., by the presence of different liquids in the channels), two transmission zeros arise, and the difference in magnitude (notch depth) and frequency between such transmission zeros is indicative of the difference in the dielectric properties (complex dielectric constant). A circuit schematic, including transmission line sections to describe the distributed components, lumped elements to account for the SRRs and their coupling to the lines and lumped elements to model the liquid properties, is presented and validated. After proper calibration, the functionality of the proposed sensor is demonstrated by measuring the complex permittivity in solutions of deionized water and ethanol as a function of the ethanol content.
266 citations
TL;DR: A general inverse design algorithm for nanophotonic devices that directly incorporates fabrication constraints is described and a compact, broadband 1 × 3 power splitter is designed on a silicon photonics platform.
Abstract: A major difficulty in applying computational design methods to nanophotonic devices is ensuring that the resulting designs are fabricable. Here, we describe a general inverse design algorithm for nanophotonic devices that directly incorporates fabrication constraints. To demonstrate the capabilities of our method, we designed a spatial-mode demultiplexer, wavelength demultiplexer, and directional coupler. We also designed and experimentally demonstrated a compact, broadband 1 × 3 power splitter on a silicon photonics platform. The splitter has a footprint of only 3.8 × 2.5 μm, and is well within the design rules of a typical silicon photonics process, with a minimum radius of curvature of 100 nm. Averaged over the designed wavelength range of 1400–1700 nm, our splitter has a measured insertion loss of 0.642 ± 0.057 dB and power uniformity of 0.641 ± 0.054 dB.
209 citations
TL;DR: An ultra-compact power splitter with a QR code-like nanostructure is designed by a nonlinear fast search method and measured transmission efficiencies of all the splitters are close to 80% over 30 nm wavelength range.
Abstract: Integrated optical power splitters are one of the fundamental building blocks in photonic integrated circuits. Conventional multimode interferometer-based power splitters are widely used as they have reasonable footprints and are easy to fabricate. However, it is challenging to realize arbitrary split ratios, especially for multi-outputs. In this Letter, an ultra-compact power splitter with a QR code-like nanostructure is designed by a nonlinear fast search method. The highly functional structure is composed of a number of freely designed square pixels with the size of 120×120 nm which could be either dielectric or air. The light waves are scattered by a number of etched squares with optimized locations, and the scattered waves superimpose at the outputs with the desired power ratio. We demonstrate 1×2 splitters with 1:1, 1:2, and 1:3 split ratios, and a 1×3 splitter with the ratio of 1:2:1. The footprint for all the devices is only 3.6×3.6 μm. Well-controlled split ratios are measured for all the cases. The measured transmission efficiencies of all the splitters are close to 80% over 30 nm wavelength range.
108 citations
TL;DR: In this paper, a broadband non-polarizing terahertz beam splitter with variable split ratio based on an all-dielectric metasurface was proposed.
Abstract: Seeking effective terahertz functional devices has always aroused extensive attention. Of particular interest is the terahertz beam splitter. Here, we have proposed, designed, manufactured, and tested a broadband non-polarizing terahertz beam splitter with a variable split ratio based on an all-dielectric metasurface. The metasurface was created by patterning a dielectric surface of the N-step phase gradient and etching to a few hundred micrometers. The conversion efficiency as high as 81% under the normal incidence at 0.7 THz was achieved. Meanwhile, such a splitter works well over a broad frequency range. The split ratio of the proposed design can be continuously tuned by simply shifting the metasurface, and the angle of emergences can also be easily adjusted by choosing the step of phase gradients. The proposed design is non-polarizing, and its performance is kept under different polarizations.
66 citations
TL;DR: A class of angle-selective metasurfaces, over which beams are reflected following different and independent phase gradients in the light of the beam direction, which holds great potential for increasing information density of compact optical components from the degree of freedom of angle.
Abstract: Synthesization of multiple functionalities over a flat metasurface platform offers a promising approach to achieving integrated photonic devices with minimized footprint. Metasurfaces capable of diverse wavefront shaping according to wavelengths and polarizations have been demonstrated. Here we propose a class of angle-selective metasurfaces, over which beams are reflected following different and independent phase gradients in the light of the beam direction. Such powerful feature is achieved by leveraging the local phase modulation and the non-local lattice diffraction via inverse scattered field and geometry optimization in a monolayer dielectric grating, whereas most of the previous designs utilize the local phase modulation only and operate optimally for a specific angle. Beam combiner/splitter and independent multibeam deflections with up to 4 incident angles are numerically demonstrated respectively at the wavelength of 700 nm. The deflection efficiency is around 45% due to the material loss and the compromise of multi-angle responses. Flexibility of the approach is further validated by additional designs of angle-switchable metagratings as splitter/reflector and transparent/opaque mirror. The proposed designs hold great potential for increasing information density of compact optical components from the degree of freedom of angle.
65 citations
TL;DR: The creation of chiral valley Hall states on the boundary between oppositely gated regions of bilayer graphene and guided through their sample using spatially modulated gating pave a path to building a scalable, coherent quantum transportation network based on the kink states.
Abstract: Developing alternative paradigms of electronics beyond silicon technology requires the exploration of fundamentally new physical mechanisms, such as the valley specific phenomena in hexagonal two-dimensional materials. We realize ballistic valley Hall kink states in bilayer graphene and demonstrate gate-controlled current transmission in a four-kink router device. The operations of a waveguide, a valve and a tunable electron beam splitter are demonstrated. The valley valve exploits the valley-momentum locking of the kink states and reaches an on/off ratio of 8 at zero magnetic field. A magnetic field enables a full-ranged tunable coherent beam splitter. These results pave the path to building a scalable, coherent quantum transportation network based on the kink states.
65 citations
TL;DR: Broadband Silicon-On-Insulator directional couplers are designed based on a combination of curved and straight coupled waveguide sections using the transfer matrix method to determine coupler section lengths, radii, and waveguide cross-sections.
Abstract: Broadband Silicon-On-Insulator (SOI) directional couplers are designed based on a combination of curved and straight coupled waveguide sections. A design methodology based on the transfer matrix method (TMM) is used to determine the required coupler section lengths, radii, and waveguide cross-sections. A 50/50 power splitter with a measured bandwidth of 88 nm is designed and fabricated, with a device footprint of 20 μm × 3 μm. In addition, a balanced Mach-Zehnder interferometer is fabricated showing an extinction ratio of >16 dB over 100 nm of bandwidth.
59 citations
TL;DR: A broadband and polarization-insensitive 2×2 3 dB power splitters based on silicon-bent directional couplers (DCs) with good agreement with the simulations is presented.
Abstract: We present and demonstrate a broadband and polarization-insensitive 2×2 3 dB power splitters based on silicon-bent directional couplers (DCs). The working bandwidth can be from 1520 to 1630 nm for both TE and TM polarizations, with an excess loss less than 1 dB. The total size for the fabricated device can be as small as 50 μm, and the measurement results show good agreement with the simulations.
49 citations
TL;DR: A plasmonic wavelength splitter based on a sub-wavelength metal-insulator-metal (MIM) periodic rectangle wrinkle waveguide with a graded grating coupler is theoretically analyzed and experimentally demonstrated.
Abstract: A plasmonic wavelength splitter based on a sub-wavelength metal-insulator-metal (MIM) periodic rectangle wrinkle waveguide with a graded grating coupler is theoretically analyzed and experimentally demonstrated. The surface plasmon polaritons (SPPs), excited in the metal grating with wavelength selection, are deflected by the graded difference according to the aplanatic parametric principle. The wave vector of the deflected SPPs meets the phase-matching condition and couples into the periodic rectangle wrinkle waveguide with a plasmonic bandgap. The characteristic of the plasmonic wavelength splitter is simulated by finite difference time domain (FDTD) simulation, which agrees well with the theoretical analysis. By electron beam lithography and ion beam etching process, the plasmonic wavelength splitter was fabricated. The SPPs excited by incident 650 and 832 nm were successfully split and guided to opposite directions of the MIM waveguide with extinction ratios of 27.5 dB and 32.7 dB, respectively, which was observed under an optical microscope using a CCD camera. The proposed wavelength splitter is simple fabricated and has a large coupling aperture by utilizing the graded grating coupler.
41 citations
TL;DR: In this article, a 1 × 16 power splitter based on a variable multicore photonic crystal fiber (PCF) structure is described, where the input optical signal at a wavelength of 1.55μm inserted into the central core was divided into sixteen output cores, each with 6.25% of the total power.
38 citations
TL;DR: In this article, an ultra-short polarization beam splitter based on dual-core photonic crystal fiber with square lattice is proposed, where an ideal coupling length and coupling length ratio can be achieved by changing the pitch in two polarizations and the ellipticity.
Abstract: An ultra-short polarization beam splitter based on dual-core photonic crystal fibre with square lattice is proposed. Numerical results show that an ideal coupling length and coupling length ratio can be achieved by changing the pitch in two polarizations and the ellipticity. The length of splitter is 93.3μm, the bandwidth is about 70 nm as the extinction ratio lower than -20dB at the wavelength of 1.55μm. The characteristic of the short length is rare in previous literatures which could widely apply to integrated optical communication systems.
TL;DR: In this article, a cross-armchair GNR is used as a beam splitter with a tunable ratio around 50% and with almost negligible back-reflection, and the split electron wave is found to propagate partly straight across the intersection region in one ribbon and partly in one direction of the other ribbon.
Abstract: Graphene nanoribbons (GNRs) are promising components in future nanoelectronics due to the large mobility of graphene electrons and their tunable electronic band gap in combination with recent experimental developments of on-surface chemistry strategies for their growth. Here, we explore a prototype 4-terminal semiconducting device formed by two crossed armchair GNRs (AGNRs) using state-of-the-art first-principles transport methods. We analyze in detail the roles of intersection angle, stacking order, inter-GNR separation, GNR width, and finite voltages on the transport characteristics. Interestingly, when the AGNRs intersect at θ=60°, electrons injected from one terminal can be split into two outgoing waves with a tunable ratio around 50% and with almost negligible back-reflection. The split electron wave is found to propagate partly straight across the intersection region in one ribbon and partly in one direction of the other ribbon, i.e., in analogy with an optical beam splitter. Our simulations further identify realistic conditions for which this semiconducting device can act as a mechanically controllable electronic beam splitter with possible applications in carbon-based quantum electronic circuits and electron optics. We rationalize our findings with a simple model suggesting that electronic beam splitters can generally be realized with crossed GNRs.
TL;DR: In this article, the authors proposed a novel nanoscale multimode interference power splitter utilizing an InP-based hybrid plasmonic waveguide at an optical communication wavelength.
Abstract: The present study proposes a novel nanoscale multimode interference (MMI) power splitter utilizing an InP-based hybrid plasmonic waveguide at an optical communication wavelength. The layer stack has the potential to realize monolithic integrated hybrid plasmonic passive and active components. The 1 × 2, 1 × 3, and 2 × 2 MMI power splitters were simulated and optimized using a three-dimensional finite difference time domain method. The effect of MMI length, width, and wavelength on optical power transmission was investigated. Transmission was higher than 90% at 1.55 μm wavelengths. This study also presents an ultracompact shallow to deep transition between shallow-etched conventional waveguide and a hybrid plasmonic waveguide on an InP-substrate. It was shown that shallow to deep transition with a length of 2 μm has a coupling efficiency of 87.5%.
TL;DR: In this paper, a 1 × 4 optical power splitter using seven horizontal slotted waveguides is presented. But the power analysis has been done in transverse magnetic (TM) polarization mode and a compact optical splitter as short as 14.5μm was demonstrated.
Abstract: In this paper, we demonstrate a compact silicon on insulator (SOI) 1 × 4 optical power splitter using seven horizontal slotted waveguides. Aluminum nitride (AIN) surrounded by silicon (Si) was used to confine the optical field in the slot region. All of the power analysis has been done in transverse magnetic (TM) polarization mode and a compact optical power splitter as short as 14.5 μm was demonstrated. The splitter was designed by using full vectorial beam propagation method (FV-BPM) simulations. Numerical investigations show that this device can work across the whole C-band (1530–1565 nm) with excess loss better than 0.23 dB.
TL;DR: In this paper, a two-dimensional numerical study is carried out to analyze the drag reduction and vortex shedding suppression behind a square cylinder in presence of splitter plate arranged in upstream, downstream and both upstream and downstream location at low Reynolds number (Re = 160).
Abstract: A two-dimensional numerical study is carried out to analyze the drag reduction and vortex shedding suppression behind a square cylinder in presence of splitter plate arranged in upstream, downstream and both upstream and downstream location at low Reynolds number (Re = 160). Computations are performed using a Single relaxation time lattice Boltzmann method (SRT-LBM). Firstly, the code is validated for flow past a single square cylinder. The obtained results are compared to those available in literature and found to be in good agreement. Numerical simulations are performed in the ranges of 1 ≤ L ≤ 4 and 0 ≤ g ≤ 7, where L and g are the length of splitter plate and gap spacing between the splitter plate and main square cylinder, respectively. The effect of these parameters on the vortex shedding frequency, time-trace analysis of drag and lift coefficients, power spectra analysis of lift coefficient, vorticity contours visualization and force exerted on the cylinder are quantified together with the observed flow patterns around the main cylinder and within the gap spacings. The observed results are also compared with a single square cylinder without splitter plate. We found that at some combinations of L and g, the mean drag coefficient and Strouhal number reach either its maximum or minimum value. It is found that the drag is reduced up to 62.2 %, 13.3 % and 70.2 % for upstream, downstream and dual splitter plates, respectively as compared to a single square cylinder (without splitter plate). In addition, in this paper we also discussed the applications of SRT-LBM for suppression of vortex shedding and reduction of the drag coefficients.
TL;DR: A new scheme for a reciprocal optical diode integrated in a multimode silicon waveguide that brings together advantages including a high contrast ratio (>0.94), a large operational bandwidth (100nm) and a small footprint (4μm long).
Abstract: In this paper, we propose a new scheme for a reciprocal optical diode integrated in a multimode silicon waveguide. The compact 4μm long functional region consists of a tapered coupler, a narrow single-mode waveguide, and a half-elliptical silver surface plasmonic splitter with refractive index modification of silicon. This spatial asymmetric design achieves even-to-odd mode conversion in the forward direction and blocks propagation of the even mode in the backward direction. The maximum contrast ratio and forward transmission efficiency reach approximately 0.99 and 87% while the values respectively keep higher than 0.96 and 80% within a 100nm operational bandwidth in a two-dimensional design. Both freestanding and SOI-based three-dimensional devices are simulated and at least a 0.94 contrast ratio is observed. Moreover, the robustness is demonstrated by introducing deviations to the surface plasmonic splitter. The proposed scheme brings together advantages including a high contrast ratio (>0.94), a large operational bandwidth (100nm) and a small footprint (4μm long).
TL;DR: In this article, an intelligent symmetric-rate 8- × 10-Gb/s bidirectional time and wavelength-division multiplexed passive optical network with 42-km reach and 1:256 split 1425-nm laser pump light provides distributed Raman amplification for the upstream channels, serves as a low-rate telemetry channel, and powers an intelligent splitter module that provides supervision for mission-critical services.
Abstract: We demonstrate an intelligent symmetric-rate 8- × 10-Gb/s bidirectional time and wavelength-division multiplexed passive optical network with 42-km reach and 1:256 split 1425-nm laser pump light provides distributed Raman amplification for the upstream channels (allowing low-cost low-power transmitters), serves as a low-rate telemetry channel, and powers an intelligent splitter module that provides supervision for mission-critical services
TL;DR: In this article, a 1 × 5 power splitter was proposed by introducing line defects to form a one input waveguide arm and five output waveguide arms, and the total observed transmission efficiency of the splitter is 99.2%.
01 Apr 2017
TL;DR: This paper presents a simple method for German compound splitting that combines a basic frequency-based approach with a form-to-lemma mapping to approximate morphological operations and outperforms a splitter relying on rich morphological resources.
Abstract: This paper presents a simple method for German compound splitting that combines a basic frequency-based approach with a form-to-lemma mapping to approximate morphological operations. With the exception of a small set of hand-crafted rules for modeling transitional elements, this approach is resource-poor. In our evaluation, the simple splitter outperforms a splitter relying on rich morphological resources.
TL;DR: This proposed structure can be used to construct an ultra-compact fast-tunable beam splitter, filter, modulator, and switch in the mid-infrared range.
Abstract: This paper presents a sheet of graphene-ribbon waveguide as a simple and ultra-compact splitter and filter in the mid-infrared waveband. The central wavelength of the graphene surface plasmons (GSPs) and the coupling intensity of this splitter can be tuned by changing the physical parameters, such as the chemical potential, the width of the waveguide, the gap between neighboring graphene ribbons, the refractive index of the substrate, the carrier relaxation time, etc. The effects of these parameters on GSP waves and beam-splitter specifications are numerically depicted based on the finite-difference time-domain method. This proposed structure can be used to construct an ultra-compact fast-tunable beam splitter, filter, modulator, and switch in the mid-infrared range.
TL;DR: In this article, the effects of splitter blade on the pump performance and flow characteristics in a high-speed scenario are discussed. And the splitter blades are added to improve pump performance.
Abstract: To add the splitter blades is an important technique to improve the pump performance characteristics. The effects of splitter blade on the pump performance and flow characteristics in a high-speed ...
TL;DR: A thermally induced optical beam-power splitter concept based on a shape memory polystyrene film with programmable micropatterns that can be adapted to further extend the applications of micro/nanophotonic devices and implement new features in the nanophotonics.
Abstract: Micro/nanophotonic structures that are capable of optical wave-front shaping are implemented in optical waveguides and passive optical devices to alter the phase of the light propagating through them. The beam division directions and beam power distribution depend on the design of the micro/nanostructures. The ultimate potential of advanced micro/nanophotonic structures is limited by their structurally rigid, functional singleness and not tunable against external impact. Here, we propose a thermally induced optical beam-power splitter concept based on a shape memory polystyrene film with programmable micropatterns. The smooth film exhibits excellent transparency with a transmittance of 95% in the visible spectrum and optical stability during a continuous heating process up to 90 °C. By patterning double sided shape memory polystyrene film into erasable and switchable micro-groove gratings, the transmission light switches from one designed light divided directions and beam-power distribution to another because of the optical diffraction effect of the shape changing micro gratings during the whole thermal activated recovery process. The experimental and theoretical results demonstrate a proof-of-principle of the beam-power splitter. Our results can be adapted to further extend the applications of micro/nanophotonic devices and implement new features in the nanophotonics.
TL;DR: In this article, a novel design of an ultra-compact polarization splitter based on soft glass photonic crystal fiber with a central chalcogenide glass rod is reported and analyzed.
Abstract: In this paper, a novel design of an ultra-compact polarization splitter based on soft glass photonic crystal fiber with a central chalcogenide glass rod is reported and analyzed. In order to enhance the birefringence between even and odd modes for the proposed design, large cladding air holes are infiltrated by nematic liquid crystal material. The numerical results show that the reported splitter has a short device length of 111.244 μm with bandwidths of 76 and 88 nm and crosstalk of −50 and −55 dB for x and y-polarization modes, respectively at wavelength of 1.55 μm. Therefore, the suggested polarization splitter has advantages in terms of compactness, large bandwidth and low crosstalk for the two polarization states.
TL;DR: In this article, the design, fabrication and optical properties of large core multimode optical polymer splitter fabricated using fill up core polymer in substrate that was made by 3D printing technology were reported.
TL;DR: In this paper, a surface plasmon resonance based on polarization beam splitter (PBS) was proposed by using a dual-core photonic crystal fiber with magnetic fluid.
Abstract: A tunable surface plasmon resonance based on polarization beam splitter (PBS) is proposed by using a dual-core photonic crystal fiber with magnetic fluid. Propagation characteristics of the PBS are analyzed by finite element method. The resonance wavelength which satisfied the phase matching condition shifts when change external magnetic field. Simulation results show that incident light wavelengths with a wide range of 1.45–
$$1.55\,\mu$$
m can be split, the minimum bandwidth of 168 nm and the extinction ratio can reach to − 128 dB when external magnetic field range 400–760 Oe at the same structure.These properties make the splitter we proposed a competitive candidate for fiber beam splitter.
Patent•
02 Aug 2017TL;DR: In this paper, a row of optical units, each of the optical units comprising an antenna element and an associated phase shifting element, a first optical power splitter optically coupled to the first optical input/output element, and a first plurality of boundary adjustment elements, are described.
Abstract: An optical device includes a row of optical units, each of the optical units comprising an antenna element and an associated phase shifting element, a first optical power splitter optically coupled to a first optical input/output element, and a first plurality of boundary adjustment elements. In the optical phased array, each of the first plurality of boundary adjustment units optically couples the first optical power splitter to different sub-rows of the row of optical units, and each of the plurality of boundary adjustment elements include a sub-row amplitude adjustment element and a sub-row phase adjustment element.
TL;DR: In this article, a numerical study on the influence of cross sectional shape of floor splitter on the effectiveness of vorticity reduction in pump intake was carried out with the aid of computational fluid dynamics (CFD) software.
TL;DR: In this article, a ray inserted method (RIM) is introduced to design dielectric optical devices. And the validity of the introduced approach is verified by designing three types of optical devices, i.e., power splitter, bend, and flat lens.
TL;DR: In this article, an experimental study on the countermeasure of scour depth at circular piers is presented, where different combinations of lengths and thicknesses of splitter plates were tested attaching each of them to a pier at the upstream vertical plane of symmetry.
Abstract: Results of an experimental study on the countermeasure of scour depth at circular piers are presented. Experiments were conducted for pier scour with and without a splitter plate under a steady, uniform clear-water flow condition. The results of pier scour without splitter plate were used as a reference. Different combinations of lengths and thicknesses of splitter plates were tested attaching each of them to a pier at the upstream vertical plane of symmetry. Two different median sediment sizes (d
50 = 0.96 and 1.8 mm) were considered as bed sediment. The experimental results show that the scour depth consistently decreases with an increase in splitter plate length, while the scour depth remains independent of splitter plate thickness. In addition, temporal evolution of scour depth at piers with and without a splitter plate is observed. The best combination is found to be with a splitter plate thickness of b/5 and a length of 2b. Here, b denotes the pier diameter. An empirical formula for the estimation of equilibrium scour depth at piers with splitter plates is obtained from a multiple linear regression analysis of the experimental data. The flow fields for various combinations of circular piers with and without splitter plate including plain bed and equilibrium scour conditions were measured by using an acoustic Doppler velocimeter. The turbulent flow fields for various configurations are investigated by plotting the velocity vectors and the turbulent kinetic energy contours on vertical and horizontal planes. The splitter plate attached to the pier deflects the approach flow and thus weakens the strength of the downflow and the horseshoe vortex, being instrumental in reducing the equilibrium scour depth at piers. The proposed method of pier scour countermeasure is easy to install and cost effective as well.
TL;DR: An x-ray beam splitter with high performances for multi-kilo-electron-volt photons, based on diffraction on kinoform structures, which overcome the limitations of binary diffraction gratings is demonstrated.
Abstract: We demonstrate an x-ray beam splitter with high performances for multi-kilo-electron-volt photons. The device is based on diffraction on kinoform structures, which overcome the limitations of binary diffraction gratings. This beam splitter achieves a dynamical splitting ratio in the range 0-99.1% by tilting the optics and is tunable, here shown in a photon energy range of 7.2-19 keV. High diffraction efficiency of 62.6% together with an extinction ratio of 0.6% is demonstrated at 12.4 keV, with angular separation for the split beam of 0.5 mrad. This device can find applications in beam monitoring at synchrotrons, at x-ray free electron lasers for online diagnostics and beamline multiplexing and, possibly, as key elements for delay lines or ultrashort x-ray pulses manipulation.