Showing papers on "Splitter published in 2003"

Polarization splitter based on photonic crystal fibers

Abstract: We report a new kind of polarization splitter based on dual-core photonic crystal fibers. The polarization splitter has a symmetric directional coupler configuration. Each core exhibits high birefringence, which gives rise to an adequate difference in the coupling lengths for the two orthogonal polarizations. A 1.7-mm-long splitter is obtained with the splitting ratio better than -11 dB and a bandwidth of 40 nm. The relationship between the length of the polarization splitter and the diameter of the air hole in the middle of the two cores is discussed.

Design and fabrication of a significantly shortened multimode interference coupler for polarization splitter application

Abstract: We report that we have successfully designed and fabricated a significantly shortened multimode interference coupler for application in polarization splitter, using a phenomenon that we termed "quasi-state" (QS) imaging effect. First, we identified and analyzed the QS imaging effect, and, based on the QS analysis, designed and fabricated a novel multimode interference (MMI) device with its split length shortened to 1/5 of a normally designed MMI split length. The fabrication is simple and cost effective and the fabricated device shows outstanding characteristics in extinction ratio, signal homogeneity, excess loss, and tolerance in the length of the splitter.

Electro-optical integrated transmitter chip for arbitrary quadrature modulation of optical signals

Abstract: An optical device includes, a first Mach-Zehnder modulator (105, 106) that produces a first output and a second Mach-Zehnder modulator (205, 206) which produces a second output. A splitter (212 )couples the first and second Mach-Zehnder modulators. A combiner (213) combines the first and second outputs. A phase shifter (107, 207) is coupled to the first and second Mach-Zehnder modulators. The first Mach-Zehnder modulator, second Mach-Zehnder modulator, splitter, combiner and the phase shifter are each formed as part of a single chip made of electro-optical material. Such two similar optical device integrated together with polarization combiner provide a two-polarization performance.

Optical mapping apparatus with optimized OCT configuration

Abstract: OCT apparatus includes an interferometer, having an input beam splitter and a 50/50 output splitter. The splitting ratio of the input splitter may be optimized depending on the source power of light source and on the mismatch of the balanced receiver. The input splitter is a plate beam-splitter to minimize the stray reflected light in the interferometer and allow sequential operation of the apparatus in the OCT or in the confocal regime. The switching between the two regimes may be at will, or synchronous with the en-face scanning which results in quasi-simultaneous OCT/confocal imaging or in alternatives frames, confocal and OCT. By using polarization sensitive elements, two channels are provided in each regime, OCT and confocal. The two confocal polarization sensitive channels may allow adjustments of compensators prior to OCT measurements or OCT imaging.

Optical network unit, wavelength splitter and optical wavelength-division multiplexing access system

Abstract: In an optical wavelength division multiplexed access system, a center unit (OSU) and n optical network units (ONUs) are connected together via a wavelength splitter and optical fiber transmission lines, and downstream optical signals from the OSU to the ONUs and upstream optical signals from the ONUs to the OSU are transmitted in both directions, the wavelength spacing Δλd (optical frequency spacing Δfd) of the downstream optical signals is set to twice or more the wavelength spacing Δλu (optical frequency spacing Δfu) of the upstream optical signals, each ONU transmits an upstream optical signal whose optical spectral width is twice or more Δλu (Δfu), and the wavelength splitter spectrum slices the upstream signals transmitted from the ONUs into wavelengths (optical frequencies) whose optical spectral widths are mutually different within Δλu (Δfu), and wavelength-division multiplexes them and transmits to the OSU

Photonic channelized RF receiver employing dense wavelength division multiplexing

Abstract: A photonic channelized receiver includes: an optical source, an optical combiner, an electro-optical modulator, an etalon, a wavelength splitter, and a set of detectors. The optical source produces a set of optical signals at spaced wavelengths, and the optical combiner combines the optical signals into a common beam. The electro-optical modulator modulates the common beam with an RF signal to produce sidebands offset from frequencies of the optical signals by the RF signal frequency. The etalon has a periodic transfer function that filters the modulated common beam such that the signals in the filtered, modulated common beam function as receiver channels corresponding to respective RF frequencies. The wavelength splitter separates the common beam into channel output signals whose intensities are a function of the frequency of the RF signal. The detectors measure the intensities of the channel output signals to determine the frequency of the RF signal.

Dynamic radio-signal memory device

Abstract: FIELD: radio signal generation and processing. SUBSTANCE: dynamic memory device has transmitting optical module 3, N fiber-optic delay lines 9, control unit 5, and photodetector 6 whose output functions as device output; novelty is introduction of broadband amplifier 1, power splitter 2, fiber- optic amplifier 4, Y-type isolating fiber-optic directional coupler 7, 2N fiber-optic switches 8, N 1 X- type fiber-optic directional couplers 10, and Y-type fiber-optic adding directional coupler 11, input being input of broadband amplifier 1 whose output is connected to input of power splitter 2; first output of the latter is connected to power input of transmitting optical module 3 whose optical output is connected through fiberoptic amplifier 4 to input of Y-type isolating fiber-optic directional coupler 7. EFFECT: enlarged capabilities of controlling copy sequence shaping process at high identity of copies and low optical fiber consumption. 1 cl, 33 dwg

Optical transmission system, optical transmitter and methods thereof

Abstract: PROBLEM TO BE SOLVED: To extend a distance of polarization-multiplexing. SOLUTION: In an optical transmitter 10, VSB modulators 24A and 24B respectively apply VSB modulations to input laser light with data D1 and D2 and output linearly polarized signal lights S1 and 32 to a polarized beam splitter 26. The VSB modulator 24A removes a sideband on a long wavelength side, and the VSB modulator 24B removes a sideband on a short wavelength side. The splitter 26 composes the signal lights S1 and S2 by an orthogonal polarization and outputs the light to an optical transmission line 12. In an optical receiver 14, the input light from the optical transmission line 12 is inputted to a polarized beam splitter 32 via a polarization tracking device 30 and split into mutually orthogonal polarized signal lights Sa and Sb. Optical filters 34A and 34B respectively remove sideband components unnecessary for receiving the signal lights S1 and S2 from the signal lights Sa and Sb. Receivers 36A and 36B respectively demodulate the data D1 and D2 from the output signal lights of the optical filters 34A and 34B. COPYRIGHT: (C)2004,JPO

Investigation of an Inversely Designed Centrifugal Compressor Stage: Part 1 — Design and Numerical Verification

Abstract: In this paper the three-dimensional inverse design code TURBOdesign-1 is applied to the design of the blade geometry of a centrifugal compressor impeller with splitter blades. In the design of conventional impellers the splitter blades normally have the same geometry as the full blades and are placed at mid-pitch location between the two full blades, which can usually result in a mismatch between the flow angle and blade angles at the splitter leading edge. In the inverse design method the splitter and full blade geometry is computed independently for a specified distribution of blade loading on the splitter and full blades. In this paper the basic design methodology is outlined and then the flow in the conventional and inverse designed impeller is compared in detail by using computational fluid dynamics (CFD) code TASCflow. The CFD results confirm that the inverse design impeller has a more uniform exit flow, better control of tip leakage flow and higher efficiency than the conventional impeller. The results also show that the shape of the trailing edge geometry has a very appreciable effect on the impeller Euler head and this must be accurately modeled in all CFD computations to ensure closer match between CFD and experimental results. Detailed measurements are presented in part II of the paper.

Microscope, particularly a laser scanning microscope with adaptive optical arrangement

Abstract: A microscope, particularly a laser scanning microscope, with an adaptive optical device in the microscope beam path, comprising two reflective adaptive elements, at least one of which is constructed as an adaptive optical element, both of which are oriented with their reflector surface vertical to the optical axes of the microscope beam path, and a polarizing beam splitter whose splitter layer is located in the vertex of two orthogonal arms of the microscope beam path or two orthogonal portions of a folded microscope beam path, wherein a first adaptive element is associated with one arm and the other adaptive element is associated with the second arm, and a quarter-wave plate is located in each arm between the beam splitter and reflective adaptive element, and a detection device to which the detection light is directed and which is linked to the adaptive elements by evaluating and adjusting devices.

Power splitter having counter rotating circuit lines

Abstract: A power splitter that has a small package size and low cross-talk noise. The power splitter includes a low temperature co-fired ceramic (LTTC) substrate with several layers. Electrical components such as transmission lines and resistors are integrated onto and within the LTCC substrate. The power splitter provides impedance matching and dividing functions. The LTCC substrate has counter rotating spiral shaped circuit lines and electrically conductive vias extending therethrough. The vias are used to connect the power splitter to an external printed circuit board. The vias are also used to make electrical connections between the layers of the LTCC substrate. The counter rotating circuit lines allow the power splitter to have a small package size and low cross-talk noise.

Systems and methods for managing optical fibers and components within an enclosure in an optical communications network

Abstract: The preferred embodiments of the present invention include an optical splitter module having connectorized pigtails that are stored on the bulkhead faceplate of the module. The module includes an optical splitter output harness, for example, a ribbon cable assembly attached to the bulkhead with rugged strain relief mechanism. The ribbon harness is converted to individual pigtails with connectors which are stored on adapter receptacles on the faceplate. Adapter receptacles used may optionally be half receptacles when storage is the only desired function or may be full receptacles when access to the pigtail ferrule tip is required. Access to the ferrule tip may be required for attaching fiber optic terminators to eliminate undesirable reflections caused by unterminated connectors. The module provides an administrative location for splitter outputs prior to being connected individually into service. The module also provides an administrative storage location for splitter outputs taken out of service as a temporary staging area before being reassigned and connected individually into service again.

Optical add/drop node and method

Abstract: An add/drop node (OADN) comprises a network optical fiber carrying a signal on an optical network. A network drop splitter is coupled to the network optical fiber and to stages of drop splitters, the states of drop splitters being operable to passively split an optical signal from the network drop splitter into multiple copies of the signal. The OADN further comprises at least one filter operable to receive at least a copy of the signal from at least one drop splitter to create a filtered copy, and further comprises at least one broadband receiver operable to receive the filtered copy from the filter.

An active traffic splitter architecture for intrusion detection

Abstract: Scaling network intrusion detection to high network speeds can be achieved using multiple sensors operating in parallel coupled with a suitable load balancing traffic splitter. This paper examines a splitter architecture that incorporates two methods for improving system performance: the first is the use of early filtering where a portion of the packets is processed on the splitter instead of the sensors. The second is the use of locality buffering, where the splitter reorders packets in a way that improves memory access locality on the sensors. Our experiments suggest that early filtering reduces the number of packets to be processed by 32%, giving a 8% increase in sensor performance, while locality buffers improve sensor performance by about 10%. Combined together, the two methods result in an overall improvement of 20% while the performance of the slowest sensor is improved by 14%.

Experimental demonstration of two-dimensional multimode-interference optical power splitter

Abstract: A two-dimensional multimode-interference optical power splitter is designed and demonstrated. The new device can be used for the optical power splitting in two transverse directions. Silicon-on-insulator technology is utilized to fabricate the device. The performance of the device is tested.

Redundant apparatus and method for gigabit ethernet passive optical network system and frame format thereof

Abstract: A GE-PON (Gigabit Ethernet Passive Optical Network) apparatus includes a 2×N splitter, an OLT (Optical Line Terminal) connected to the 2×N splitter via a first path line or a second path line, and a switching unit for switching the first path line or the second path line upon receiving a predetermined control signal An ONU (Optical Network Unit) generates a switching request according to a signal environment and transmits the generated switching request to the OLT

Integrated optical waveguide structures

Abstract: A multifunctional integrated optical waveguide is provided. The planar optical waveguide structure includes an active gain medium for optical amplification, and a passive component(s) (i.e. arrayed waveguide grating, splitter, and tap) for processing the signal (i.e. multiplexing, demultiplexing, monitoring, add-dropping, routing and splits) on a solid substrate.

Compact Y-branch power splitter based on simplified coherent coupling

Abstract: Based on a simplified coherent coupling effect, a compact Y-branch power divider with polymer waveguides is presented. The simulated and measured normalized transmitted powers are 0.88 and 0.75 when the effective branching angle is as large as 19.7/spl deg/. For the same transmission efficiency, both theoretical and experimental results show that the length required for the proposed Y-branch is shorter than those for the conventional S-bend configurations. Furthermore, the transmission spectrum shows that the proposed Y-branch is suitable for a dense wavelength-division-multiplexing application.

Microfluidic multi-splitter

Abstract: A splitter for multi-layer microfluidic devices is provided. The splitter includes multiple forked channels defined in two or more device layers. The forked channels communicate fluidically at overlap regions. The overlap regions, in combination with symmetrical channel geometries balance the fluidic impedance in the system and promote even splitting.

An original SiGe active differential output power splitter for millimetre-wave applications

Abstract: This paper deals with an original design of an active power splitter featuring a differential output presenting a greatly enhanced even mode rejection. The proposed circuit consists in two cascaded common emitter and common collector differential pairs. For achieving the best performance, it is shown that each of these two differential pairs requires a specific common node to ground impedance that is discussed. The circuit has been implemented on a 0.25/spl mu/m SiGe BiCMOS process and exhibits anticipated phase and amplitude broadband unbalance less than 6.5/spl deg/ and 0.6 dB respectively all over the 6-27 GHz frequency range. At 20 GHz, a common mode rejection ratio better than 43 dB is predicted, i.e. a maximum 0.12 dB /0.35/spl deg/ output signal unbalance.

Narrow band tunable filter with integrated detector

Abstract: A polarization insensitive narrowband tunable filter utilizes an active liquid crystal cell to change the index of refraction and tuning of a waveguide resonant filter employing a nanostructured waveguide grating and polarization beam splitters to independently channel and convert S- and P-polarization states into optically and geometrically parallel beams which pass through the device A multi-pixel configuration offers extended tuning range by employing a 1×N optical switch or splitter and N tunable pixel-filters each having offset center frequency enabling the tuning range of one pixel to partially overlap another pixel rendering the device and 1×N switch or splitter capable of scanning pixels to yield an expanded continuous tuning range mode Optional features of the present invention include deposited photodetectors, deposited metal gasket moisture barrier, deposited spacer layer with high cell gap tolerance, a deposited thermal sensor and heater and related temperature compensation control schemes

Hybrid networking system

Abstract: A method for transmitting data signals between nodes in a networking system having one or more signal splitters. The method comprises transmitting wired and wireless data signals between nodes at a same frequency at which the effective isolation of each signal splitter at that frequency is substantially less than the specified effective isolation of each splitter. The invention also provides a wired networking system comprising one or more signal splitters. Each node in the system is configured to transmit and receive wired and wireless data signals over the system at a same frequency at which the effective isolation of each splitter is less than the specified effective isolation of each splitter.

Photonic-crystal 180° power splitter based on coupled-cavity waveguides

Abstract: We propose a structure that allows the splitting of electromagnetic waves with a phase shift of 180° between output signals based on photonic crystals. The structure consists of two parallel coupled-cavity waveguides placed in proximity. The performance of the splitting structure is theoretically discussed, evaluated by means of finite-difference time-domain method simulations and experimentally demonstrated at microwave frequencies. As both output paths have the same physical length, the two output signals are synchronized, which is very attractive for splitting high-speed optical signals in photonic-crystal-based integrated circuits.

System and method for voice/data transmission over cable networks

Abstract: A wireless communications system comprises a first splitter (105) separating at least two signals, a wireless circuit for processing a first signal as a wireless signal and a combiner connected to the wireless circuit (107 & 109) and the splitter (105), combining the two signals and transmitting the signals into a service area. The wireless communications system further comprises a second splitter (115) separating the wireless signal from a second signal, and a transmitter (113) for broadcasting the wireless signal.

Optical splitter with tapered multimode interference waveguide

Abstract: A 1×2 splitter design having low loss is described. The splitter has a non-adiabatic tapered waveguide ( 22 ) connected between a substantially single-mode input waveguide ( 20 ) and two output waveguides ( 24, 26 ). The non-adiabatic tapered waveguide widens in width towards the output waveguide, and merges substantially continuously with the input waveguide in a direction parallel to the optical axis of the input waveguide. This keeps radiation mode generation to a minimum which, in turn, keeps insertion loss low. In the described embodiment, the non-adiabatic taper shape is based on a perturbed cosine function. The 1×2 splitter can be cascaded with other such splitters in order to build a 1×2N splitter design.

Method of and system for multi-path communication

Abstract: The invention relates to a method of and to a system (1000) for dealing with network congestion. A first internetworking device (100) may have several paths available (110; 120) for accessing a second device (400) through a network (AN1; AN2). The first device may e.g. have a low-bandwidth connection that is always operational and/or a high-bandwidth connection which is only operational when the device in its docking station. The basic concept of the invention is embodied in a splitter/merger device (130) that proxies a connection (1), such as a TCP-connection, splits the connection (1) into multiple separate connections (2, 3) which are available, and routes packets (140) over these multiple connections to an external splitter/merger component (200) . The splitter/merger device (130; 134; 142; 144; 152) divides the packets over the available connections in dependence of the progress of transport along each of these connections (2, 3). The functions of the splitter/merger components (130; 200) are symmetric and mirrored if there is both incoming (620; 140, 600) and outgoing (140; 500, 620) traffic.

Splitter imperfections in annular split-flow thin separation channels: experimental study of nonspecific crossover.

Abstract: The separation performance of a split-flow thin (SPLITT) separation device depends on uniformity of channel thickness and the precise placement of the flow splitters at fixed distances between the channel walls. The observation of nonspecific crossover, that is, the transport of sample materials across the channel thickness without the influence of an applied field, has routinely been taken to indicate the presence of irregularities in splitter shape or placement. Computational fluid dynamics software may be used to predict the influence of splitter imperfections on nonspecific crossover, where it is assumed that sample transport is by convection alone. A previous study has shown how small inlet splitter imperfections can account for the relatively low levels of nonspecific crossover observed with typical annular SPLITT devices. This study, however, could not distinguish between the possible sources of nonspecific crossover; hydrodynamic lift or shear-induced diffusion could have contributed. To confirm t...

Properties of a 1 × 4 optical power splitter made of photonic crystal waveguides

Abstract: Optical power splitters made of photonic crystal waveguides are believed to become essential components for compact photonic integrated circuits used in fiber optic networks. We design a 1 × 4 optical power splitter made of linear-defect waveguides in photonic crystals, and analyze its properties using the finite-difference time-domain method. Our simulation results show that the transmission properties vary with wave frequency and branch geometry, and that an incident wave is divided equally into four output ports. To reduce the reflections at the three branching regions in the 1 × 4 splitter, we place the defects of extra rods in the branching region, and achieve high transmission in each output waveguide.

Multimode interference-based two-stage 1 /spl times/ 2 light splitter for compact photonic integrated circuits

Abstract: A novel two-stage multimode interference 1 /spl times/ 2 light splitter is proposed and fabricated in indium phosphide. The new splitter design is shorter by as much as 50% than a standard multimode-interference light splitter with the same output waveguide spacing. It has low inherent loss of 0.29 dB, low excess loss of 1.5 dB over 80-nm range, and imbalance of less than 0.25 dB over 100 nm.

Non-switching adaptable 4-way power splitter/combiner

Abstract: A 4-way power splitter/combiner circuit providing a plurality of transmission lines of selected impedance and phase shift to define four amplifier ports into which one to four amplifiers may be populated without reconfiguration of the circuit. The circuit provides acceptable VSWR and return loss under each operating condition.