Showing papers on "Splitter published in 2014"

Using I/O track information for continuous push with splitter for storage device

Abstract: Methods and apparatus for eliminating the need for a complete synchronization due to failure of a data protection appliance in a continuous data protection system having a replication splitter. In one embodiment, a continuous data protection system includes a source side having a source side storage array with a splitter and a data protection appliance, where processing includes initiating a source side splitter session, initializing a first I/O tracking mechanism for the splitter session, and activating the splitter to a source side processing active state to continuously push I/O data from the source side to the target side.

Arbitrary-ratio 1 × 2 power splitter based on asymmetric multimode interference

Abstract: Free choice of splitting ratio is one of the main properties of a power splitter required in integrated photonics, but conventional multimode interference (MMI) power splitters can only obtain a few discrete ratios. This Letter presents both numerical and experimental results of an arbitrary-ratio 1×2 MMI power splitter, which is constructed by simply breaking the symmetry of the multimode region. In the new device, the power splitting ratio can be adjusted continuously from 100∶0 to 50∶50, while the dimension of the multimode section stays in the range of 1.5×(1.8–2.8) μm. The experimental data also indicate that the proposed arbitrary-ratio splitter keeps the original advantages of MMI devices, such as low excess loss, weak wavelength dependence, and large fabrication tolerance.

A Novel Polarization Splitter Based on Dual-Core Photonic Crystal Fiber With a Liquid Crystal Modulation Core

Abstract: A novel polarization splitter based on dual-core silica glass photonic crystal fiber with a liquid crystal modulation core is studied by the finite-element method. The mode birefringence is enlarged greatly with the infilling of nematic liquid crystal of E7. The simulation results demonstrate that the polarization splitter has an ultrabroad bandwidth of 250 nm, covering the E S C L optical communication bands, with the extinction ratio better than -20 dB. The separate length is 0.175 mm, and the extinction ratio is -80.7 dB at the communication wavelength of 1550 nm. The polarization splitter exhibits satisfactory splitter performance as the fabrication deviation reaches to 1%. The extinction ratio maintains better than -20 dB, at the C L optical communication bands, as the temperature increases from 15 °C to 50 °C.

Time domain topology optimization of 3D nanophotonic devices

Abstract: We present an efficient parallel topology optimization framework for design of large scale 3D nanophotonic devices The code shows excellent scalability and is demonstrated for optimization of broadband frequency splitter, waveguide intersection, photonic crystal-based waveguide and nanowire-based waveguide The obtained results are compared to simplified 2D studies and we demonstrate that 3D topology optimization may lead to significant performance improvements

MIM plasmonic waveguide splitter with tooth-shaped structures

Abstract: A plasmonic splitter based on subwavelength metal–insulator–metal (MIM) waveguides with tooth-shaped structures is proposed and numerically researched by using the finite-difference time-domain (FDTD) method in visible and near infrared frequencies. The splitter is regarded as two zigzag-shaped MIM waveguides, which naturally stretch out two tooth structures in bending corners. Each tooth forms a resonant cavity. The transmission of the zigzag-shaped waveguide is close to zero at some resonant wavelength of the tooth cavity. The same-order resonant wavelength has an approximately linear relationship with the depth of the tooth. When the geometric parameters of the two zigzag-shaped waveguides of teeth are suitably initialized, both frequency splitter and power splitter can be simply achieved.

Flexible TWDM PON with Load Balancing and Power Saving

Abstract: An apparatus comprising an arrayed waveguide grating (AWG) comprising a plurality of AWG ports, a power splitter comprising a plurality of splitter ports, and a plurality of optical interleavers, each coupled to a respective AWG port and a respective splitter port, for directing incoming optical signals to one of the AWG and the power splitter.

Design of an Optical Power and Wavelength Splitter Based on Subwavelength Waveguides

Abstract: A plasmonic T-shaped metal–insulator–metal waveguide followed by two or four output waveguides with ultranarrow silica slits is proposed to serve as an optical power and wavelength splitter in compact footprint. When the lengths of all silica slits are identical, uniform transmittances and identical center wavelengths are observed at all the output waveguides, and they can be tuned by changing the positions and the lengths of the slits, respectively. In addition, the proposed structure can also be used as a multichannel wavelength splitter by employing the resonance characteristics of the slits. When the silica slits are different in length, a transmission peak with a specific center wavelength will be achieved at the corresponding output waveguide, such that different wavelengths are splitted, respectively. The performances of the proposed power/wavelength splitter are demonstrated by using the finite-difference time-domain method.

Vertical polarization beam splitter using a hybrid long-range surface plasmon polariton waveguide

Abstract: A vertical polarization beam splitter using a hybrid long-range surface plasmon polariton (LR-SPP) waveguide is proposed for three-dimensional integration of silicon photonic circuits in a chip. The device is based on a three-port directional coupler that is operated based on mode coupling theory. The hybrid LR-SPP waveguide as the central waveguide in a three-port directional coupler plays a key role in transferring the transverse-magnetic (TM)-polarization mode from the input port to the cross port, which is configured with horizontal and vertical offsets. A 9.7 μm-long vertical polarization splitter with an extinction ratio of 30 dB in the C-band is achieved. The effects of dimensional tolerances are also investigated. The vertical polarization splitter is highly compatible with a complementary metal–oxide–semiconductor (CMOS) fabrication process based on the silicon-on-insulator (SOI) platform.

Numerical investigation on cascaded 1 × 3 photonic crystal power splitter based on asymmetric and symmetric 1 × 2 photonic crystal splitters designed with flexible structural defects

Abstract: We propose a photonic crystal slab-based 1 × 3 power splitter with high output transmission and equal power distribution It is designed by cascading an asymmetric 1 × 2 power splitter and a symmetric 1 × 2 power splitter Desired equal power splitting is achieved by introducing and optimizing the splitting region of the 1 × 2 power splitters with flexible structural defects Simulations were carried out by using 3-D Finite Difference Time Domain method showing equal normalized power distributions of 296%, 289% and 305% at 1550 nm optical wavelength In addition, equal power splitting also takes place at 1561 nm

Simulation of an Ultra-Compact Multimode Interference Power Splitter Based on Kerr Nonlinear Effect

Abstract: We propose an ultra-compact multimode interference (MMI) power splitter based on the Kerr nonlinear effect from simulations using modal propagation analysis. Crystalline polydiacetylene is used as the core layer to allow for the creation of a power splitter with a high number of outputs with the shortest possible multimode waveguide length operating in the nonlinear regime. The 11 high-contrast, high-resolution images at the end of the multimode waveguide in the simulated power splitter have a high power balance, whereas access to a high number of self-images is not possible under the linear regime in the proposed length range. The compact dimensions and ideal performance of the device are established according to optimized parameters. The proposed regime can be extended to the design of M × N power splitters. The results of this study indicate that nonlinear modal propagation analysis solves the miniaturization problem for all-optical devices based on MMI couplers to achieve multiple functions in a compact planar integrated circuit and also overcomes the limitations of previously proposed methods for nonlinear MMI. The results are verified using a numerical method.

Influence of Splitter Blades on the Cavitation Performance of a Double Suction Centrifugal Pump

Abstract: In order to study the influence of splitter blades on double suction centrifugal pumps two impellers with and without splitter blades were investigated numerically and experimentally. Three-dimensional turbulence simulations with and without full cavitation model were applied to simulate the flow in the two pumps with different impellers. The simulation results agreed with the experiment results and the internal flows were analyzed. Both the numerical and experimental results show that by adding splitter blades the hydraulic performance and the cavitation performance of the pump are improved. The pump efficiency is increased especially at high flow rate condition. The pump high efficiency area is extended dramatically. At the same time since the splitter blades share some part of the blade loading, the pump critical NPSH value is decreased. Obvious pressure increase and velocity decrease at blade suction surface near leading edge were observed in the pump impeller with splitter blades. And the pump cavita...

Design of Polarization Splitter With Single-Polarized Elliptical-Hole Core Circular-Hole Holey Fibers

Abstract: We propose a novel polarization splitter based on coupled elliptical-hole core circular-hole holey fibers (EC-CHFs). Utilizing the single-polarization nature of the EC-CHFs, in the proposed polarization splitter, two orthogonally polarized waves couple only to different EC-CHFs and the crosstalk-free polarization splitting is realized. In addition, the coupling length for two orthogonally polarized waves can be independently designed and this splitter is easy to design.

A multidirectional frequency splitter with band-stop plasmonic filters

Abstract: We propose a multidirectional frequency splitter with band-stop plasmonic filters, in which a double-period grating structure is adopted to produce band-stop filtering features. The multidirectional frequency splitter consists of three specially designed metallic gratings with finite thickness. Better isolation between different metallic gratings is achieved at the lower frequencies. The experimental verification of the frequency splitter is implemented at the microwave frequencies with excellent agreements to full-wave simulations. A four-way THz frequency splitter excited by the cylindrical wire is also proposed and simulated to show how the design can be scaled down to the THz frequencies for the potential applications.

Effect of arrangement of inline splitter plate on flow past square cylinder

Abstract: Two-dimensional numerical study has been carried out to investigate the effect of the presence of a single splitter plate in upstream location, and presence of two splitter plates, in upstream as well as downstream locations, for low Reynolds number incompressible flow past a square cylinder. Using finite difference discretisation and MAC algorithm, an indigenously developed computational code has been used for solution of the governing flow equations. The length of the plate and its position do play good role in controlling the flow past the cylinder. The difficulty lies in identifying an optimum configuration of these parameters. The length of the attached splitter plate as well as separation of the detached splitter plate of fixed length are varied for both the upstream and downstream configurations up to maximum Reynolds number of 200. To begin with, the effect of upstream splitter plate alone in attached as well as detached configuration is studied with an aim to identify the optimum configuration associated with reduced drag as well as delayed onset of vortex shedding. Then, for the optimum configuration of the upstream plate, the effect of downstream plate on flow characteristics and critical Reynolds number for onset of vortex shedding has been studied.

Advanced optical modulation generation by combining orthogonal polarized optical signals

Abstract: Disclosed are adaptive structures and methods for generating advanced modulation formats using multiple levels such as PAM-4, PAM-8 as well as regular OOK or PM OOK formats. Structures and methods disclosed include an unequal power splitter that may exhibit a fixed or tunable splitting ratio such that adaptive format(s) may be generated.

An effective shape of floor splitter for reducing sub-surface vortices in pump sump

Abstract: An experimental investigation on the effective shape of a floor splitter to reduce sub-surface vortices and cavitation which arise in the vicinity of the pump bells in pump sump is performed. A test model sump was designed based on the Froude number similitude for the recommended structure layout by HI-9.8 standard for pump intake design. To obtain an effective shape of the splitter as an anti-vortex device (AVD), three types of quadrilateral submerged bar with different shape and dimension in sectional area are considered. From the experimental results with and without the splitter attached on the floor under the bell mouth, it was confirmed that the installation of the AVD is very effective to reduce abnormal vortices including sub-surface vortices, pre-swirls and other undesirable hydraulic phenomena. Because of the splitter, sub-surface vortices under the bell mouth did not appear anymore and the swirl was dramatically weakened. The evaluation of AVD was made by the measurement of swirl angles indicating the strength of the vortices and pre-swirls. Splitters with square sections showed partly large swirl angles beyond the acceptable criteria of HI standard though a large square was more effective than a small one. Meanwhile, the splitter with trapezoidal section was showed swirl angle values of less than 5 degrees in all cases of pump operation. Among the three types of AVD, the trapezoidal splitter is the most effective one to suppress the vortices. It is very useful to reduce the occurrence of submerged vortices and to obtain stable inflow condition for designing a high performance pump sump.

Design and Optimization of Polarization Splitting and Rotating Devices in Silicon-on-Insulator Technology

Abstract: We review polarization splitting and rotating photonic devices based on silicon-on-insulator technology platform, focusing on their performance and design criteria. In addition, we present a theoretical investigation and optimization of some rotator and splitter architectures to be employed for polarization diversity circuits. In this context, fabrication tolerances and their influences on device performance are theoretically estimated by rigorous simulations too.

Compact Dual-Band Differential Power Splitter With Common-Mode Suppression and Filtering Capability Based on Differential-Mode Composite Right/Left-Handed Transmission-Line Metamaterials

Abstract: This letter presents a compact differential-mode (balanced) power splitter with filtering capability and dual-band functionality. This multifunctional device is based on differential-mode composite right/left-handed (DM-CRLH) transmission lines specifically designed to achieve the dual-band behavior and to suppress the common-mode noise over a broad frequency band. The DM-CRLH lines are implemented by means of pairs of CRLH lines with series connected interdigital capacitors and strip inductors in the series branches and mirrored step impedance resonators (SIRs) in the shunt branches. For the differential mode, the SIRs are described by parallel resonant tanks, and the resulting equivalent circuit model is the canonical circuit of a CRLH line, which can be used for designing the dual-band balanced splitter/filter. However, the SIRs are opened under common-mode operation, introducing transmission zeros for that mode. By tailoring the position of these transmission zeros, the common mode can be effectively rejected over a frequency band that covers the splitter operating frequencies. The fabricated dual-band balanced power splitter exhibits a measured matching level better than -11 dB, and measured insertion losses (power splitting) lower than 4.1 dB at the design frequencies ( f1=1.8 GHz and f2=2.4 GHz). The common-mode suppression at f1 and f2 is better than 30 dB.

Quantum cryptographic key distribution system including two peripheral devices and an optical source

Abstract: A quantum cryptographic key distribution system, including: an optical source (62), which generates a plurality of optical pulses; an optical beam splitter (80), which generates, starting from each optical pulse, a first and a second optical sub-pulse; a first and a second peripheral device (50, 52); and an optical path (50, 52, 82, 84, 90, 92) having a first and a second end connected to the optical beam splitter, the optical path extending through the first and second peripheral devices and being traversed in opposite directions by the first and second optical sub-pulses. The peripheral device randomly phase shifts the second optical sub-pulse by a first phase (φΑ), and the second peripheral device randomly phase shifts the first optical sub-pulse by a second phase (φB). Furthermore, the optical path is such as to cause interference in the first optical beam splitter between the first and second optical sub-pulses, as a function of first and second phases.

Numerical investigation of the effects of splitter blades on the cavitation performance of a centrifugal pump

Abstract: For the centrifugal pump, additional splitter blades are sometimes necessary in order to improve the head and efficiency. On the other hand, the additional splitter blades will have effect on the cavitation performance due to the changes at the impeller inlet channel. In order to investigate this influence, three impeller schemes were proposed based on a model pump IS50-32-160, one without splitter blades and another two with splitter blades of different inlet diameters. Numerical simulations were carried out to investigate the characteristics of internal flow and the pump cavitation performances at different NPSHA with the CFD technique. The results show that the additional splitter blades will have some positive effect on the pump cavitation performance if the inlet diameter of the splitter blade is properly selected. The reason behind such improvement is that it helps to avoid the flow blocking at the impeller inlet and the vortex cavitation inside the blade passages effectively. For the pump model under our investigation, the cavitation performance reaches its best when the inlet diameter of the splitter blade is 0.725D2.

Infrared imaging spectrometer based on light beam splitter and manufacturing method

Abstract: The invention discloses an infrared imaging spectrometer based on a light beam splitter and a manufacturing method and relates to the field of earth observation imaging spectrometers. In order to solve the problems that an interference beam splitting system in an existing imaging spectrometer is large in size, the light weight of the system cannot be conveniently achieved, a slit related to the spatial resolution is contained in the system, and the luminous flux entering the system is limited, a grid type beam splitter system is introduced in to replace a beam splitter and a compensation board in the system, and the advantages of the small size and the light weight are achieved. The light weight of the system is achieved, meanwhile, convenience is brought to design of a whole optical system, the system does not contain a slit, compared with a spatial modulation Fourier transform imaging spectrometer, the luminous flux of the system is greatly improved, the slit in the spatial modulation Fourier transform imaging spectrometer is removed, the high spectral resolution is achieved, and meanwhile the signal to noise ratio of the system is effectively improved. The infrared imaging spectrometer is based on a Michelson interferometer structure, and the reliability of the system is greatly improved.

Photonic High-Bandwidth RF Splitter With Arbitrary Amplitude and Phase Offset

Abstract: This letter presents an alternative approach to achieve a high-bandwidth RF splitter functionality based on a microwave photonic system. The proposed approach has an arbitrary amplitude and a phase offset between the two outputs. In addition, it features a simple system architecture and easy tuning mechanism. In the experimental demonstration, an instantaneous RF band from 5 to 20 GHz was shown.

Integrated laser and method of fabrication thereof

Abstract: There is provided an integrated laser. The integrated laser includes a semiconductor waveguide having a first section, a second section and a third section. The integrated laser further includes an active region formed on the third section of the semiconductor waveguide, the active region configured for generating light, and a coupler formed on the second section of the semiconductor waveguide, the coupler configured for coupling said light between the semiconductor waveguide and the active region. In particular, the first section comprises a multi-branch splitter having a ring structure formed between two branches of the multi-branch splitter for emission wavelength control of the integrated laser. Preferably, the multi-branch splitter is a Y-branch splitter and the ring structure is formed in a space between two branches of the Y-branch splitter. There is also provided a method of fabrication thereof, an integrated tunable laser and an integrated tunable laser system.

Slow-light Bragg reflector waveguide array for two-dimensional beam steering

Abstract: We propose and demonstrate a slow-light Bragg reflector waveguide array for two-dimensional (2D) beam steering. The device consists of a highly dispersive Bragg reflector waveguide array with a quarter-wavelength stack semiconductor mirrors and a Y-branch 1 × 4 splitter with a branching angle of 30°. The beam steering characteristics in the two orthogonal directions are clarified by tuning the input wavelength. Beam steering was demonstrated using wavelength tuning with the assistance of delay sections. The results show the possibility of 2D beam steering using the Bragg reflector waveguide array by combining wavelength tuning and thermo-optic phase tuning.

Quantum nature of a nonlinear beam splitter

Abstract: This is a review of a very interesting (in the authors' view) phenomenon — the operation of a nonlinear light beam splitter. The beam splitter is a flat interface between two transparent dielectrics, at least one of which exhibits Kerr nonlinearity, i.e., its refractive index depends on the transmitted radiation intensity. Interestingly, quantum and classical theories make directly opposite predictions about the phase fluctuations of the output radiation of this device. In classical theory, the phases remain unchanged; in quantum theory, the phases fluctuate in accordance with the amplitude–phase uncertainty relation. The origin of this difference is established at the fundamental level. A further remarkable point about this quantum paradox is that not only is the source beam split in two but one can also create conditions where the two split parts are respectively dominated by amplitude noise and phase noise, thus allowing the selection of photon fluctuations. Results of original studies are summarized and further developed.

Wireless redbox comprising a timing splitter

Abstract: The invention relates to a method for wireless transmission from a data source to a data sink and/or vice versa via two radio links (channels) that are independent of one another, characterised in that the transmission between the parallel redundant channels is time-staggered.

Waveguide superlattices for high density photonics integrations

Abstract: An apparatus and method for transmitting a plurality of light signals is disclosed. The apparatus includes a splitter configured to split an incoming light signal into a plurality of light signals. Phase control units are included which modify the phase of the light signals. Waveguides are coupled to the phase control units. Each waveguide has a different propagation constant, that is different from adjacent waveguides and the difference between the propagation constants of any two adjacent waveguides is substantially larger than an effective coupling constant between said two adjacent waveguides. Coupling members couple the light signal in one of the plurality of waveguides to free space. The splitter may include output and/or input waveguides and a dispersion element splitting and/or combining: light.

Design and Fabrication of Novel Symmetric Low-Loss 1 × 24 Optical Power Splitter

Abstract: In this paper, a three-branch structure with different output widths, broadening, and transition waveguide are discussed in detail. Based on the three-branch structure, a compact, low-loss, and good uniformity 1 × 24 optical power splitter is designed and fabricated using silica-based PLC technology on quartz substrate. The measurement results show that the insertion loss, the uniformity, wavelength-dependence loss of the splitter are less than 14.8, 0.92, and 0.93 dB, respectively, in the wavelength range from 1.25 to 1.65 μm. The polarization dependence loss is less than 0.16 dB in the wavelength of 1.27, 1.31, 1.49, 1.55, and 1.625 μm.