Simple Coupler Research Articles

Three-dimensional waveguide interconnects for scalable integration of photonic neural networks

Photonic waveguides are prime candidates for integrated and parallel photonic interconnects. Such interconnects correspond to large-scale vector matrix products, which are at the heart of neural network computation. However, parallel interconnect circuits realized in two dimensions, for example, by lithography, are strongly limited in size due to disadvantageous scaling. We use three-dimensional (3D) printed photonic waveguides to overcome this limitation. 3D optical couplers with fractal topology efficiently connect large numbers of input and output channels, and we show that the substrate’s area and height scale linearly. Going beyond simple couplers, we introduce functional circuits for discrete spatial filters identical to those used in deep convolutional neural networks.

A family of compensation topologies for capacitive power transfer converters for wireless electric vehicle charger

A large scale of electric vehicles can ideally maintain the stability of renewable power supply by acting as storage buffers for alleviating the intermittence in the integration of renewable energy sources for constructing a low-carbon energy system. However, the inconvenient conductive charging becomes a barrier in the popularization of electric vehicles. Wireless power transfer technology is in the spotlight because of the flexibility and convenience in powering electric vehicles. Recently, the Capacitive Power Transfer has received extensive attention due to simple coupler structure, rotatable coupler, and negligible heating of the metal foreign object. In the capacitive-based wireless charging system, the higher-order compensation topology is essential to enhance power transfer capability limited by the small coupling capacitance. However, with the increase of the resonant elements, the form of the resonant network becomes diverse. Currently, the researches focus on the characteristics of specific symmetrical compensation topologies. This paper presents a family of compensation topologies for the Capacitive Power Transfer system to achieve constant-voltage or constant-current output. A design procedure is summarized to construct the resonant networks, so as to design the compensation parameters. Considering the coupling capacitor variations caused by parking position deviation, a parameter tuning method is proposed to realize primary zero-voltage switching by adjusting the parameter of the double-sided inductor-capacitor-inductor-capacitor compensation topology. Experiments show that the prototype achieves constant-current output and zero-voltage switching when the coupling capacitance varies. The system efficiency reaches 93.57% at 1.5 kW input power with the input and output voltage around 250 V.

Polymer optical fiber tapering using chemical solvent and polishing

A method for developing polymer optical fiber (POF) directional coupler is introduced where the initial procedure includes using chemical solvent to remove the cladding, and bare out the core in order to align the unclad center of the fiber with other similar fiber to develop a coupler. The process is safe, simple, inexpensive and require low operation skill. The etched fiber offers improvement to the performance of various POF devices, i.e, couplers and sensors. Instead of relying only on silica or glass fiber, POF now can be used as an alternative to improve the network performance in short distance communication system. The measurement parameters laid out offer great outcomes. However, the couplers intended to be developed is yet to be realized, where deeper research and various experiments are needed in order to develop a simple but optimum performance coupler that can be used for various applications.

Design of Folded Waveguide Slow-Wave Structure for <inline-formula> <tex-math notation="TeX">\(W\) </tex-math></inline-formula>-Band TWT

Design of RF structure for W-band folded waveguide traveling-wave tube was accomplished using electromagnetic simulation codes CST-MWS and GdfidL. The parameters characterizing the folded waveguide structure were optimized through a detailed analysis. CST-MWS and GdfidL simulated dispersion results have been compared and found in a close agreement. The CST-particle studio and in-house developed a large-signal analysis code SUNRAY 1-D were used for a large-signal analysis. The results of the parametric analysis and large-signal analysis are presented in this paper. Dimensions have been fixed for getting a gain ~18 dB and 7% bandwidth (95-102 GHz) corresponding to a 16-kV beam line for a uniform section. A gain of nearly 24 dB was obtained by employing pitch tapering near the output section of the tube of same length. Design of folded waveguide RF structure with a simple but efficient waveguide coupler yielding a return loss better than -15 dB has been obtained in the desired band (90-105 GHz).

Linear and nonlinear Zeno effects in an optical coupler

It is shown that in a simple coupler where one of the waveguides is subject to controlled losses of the electric field, it is possible to observe optical analog of the linear and nonlinear quantum Zeno effects. The phenomenon consists in a counter-intuitive enhancement of transparency of the coupler with the increase of the dissipation and represents an optical analogue of the quantum Zeno effect. Experimental realization of the phenomenon based on the use of the chalcogenide glasses is proposed. The system allows for observation of the cross-over between the linear and nonlinear Zeno effects, as well as effective manipulation of light transmission through the coupler.

Analyzer allows testing of polar response patterns of directional hearing aids

Analyzer allows testing of polar response patterns of directional hearing aids

Design of photonic crystal power couplers via gratinglike surfaces

This work deals with the inverse design in the field of photonic crystal based devices. We use the finite-difference time-domain method in conjunction with a genetic algorithm to design a power coupler between two photonic crystal waveguides. By optimizing the structure of gratinglike surfaces added near the photonic crystal waveguides, we have obtained several simple power couplers considering different coupling lengths. These couplers have high coupling efficiency as well as high power intensity in the propagation direction.

Development of a Simple Coupler (Scup) for Earth System Modeling

地球システムモデルを作成する目的で使用可能な、汎用のシンプルなカップラーScup (Simple coupler)の開発を行った。Scupを用いて例えば大気・海洋大循環モデルや化学輸送モデルのような要素モデルを柔軟に結合することが可能である。Scupは気象研究所の地球システムモデルを効率的に開発するために必要な機能を備えており、その基本設計は他の地球システムモデルにも適用可能である。Scupライブラリを呼ぶことにより要素モデルの各々のプロセスはお互いに直接通信を行っており、このことは要素モデルのプロセス間で大容量のグリッドデータを効率的に交換するために必要である。Scupは3次元データのグリッド変換や局所的かつ全球的に正確に保存する2次元データのグリッド変換をサポートしており、これは異なる座標やグリッドを持つ要素モデルを結合するために必要な特徴である。単純さと使用しやすさはScupの長所である。ScupのすべてのソースコードはFortranで記述され、Fortran95コンパイラとMPIライブラリを有する多様なプラットフォームでコンパイル可能なので、Scupは可搬性に優れている。

Tolerance Analysis of Lattice-Form Optical Interleaver With Different Coupler Structures

A set of recursion equations is developed to synthesize a coherent two-port lattice-form optical delay-line circuit with different coupler structures. A fifth-order lattice-form optical interleaver is designed, and parameter tolerance is analyzed with crosstalk consideration. Results show that the phase tolerance of delay lines is six times the coupling-coefficient-angle tolerance of directional couplers. The coupling-coefficient-angle tolerance of directional couplers in an interleaver with stabilized couplers is improved by one order than that in an interleaver with simple directional couplers if global uniformity of the planar-lightwave-circuit process is supposed. The tolerance of an interleaver with cascaded multimode interference (MMI) couplers does not improve much, but an MMI coupler is more immune to process error than a directional coupler. Theoretical analysis meets the simulation results well. A stabilized coupler and a cascaded MMI coupler are both good substitutes for a simple directional coupler in lattice-form optical interleaver, and both help to reduce crosstalk

Force production by disassembling microtubules

Microtubules (MTs) are important components of the eukaryotic cytoskeleton: they contribute to cell shape and movement, as well as to the motions of organelles including mitotic chromosomes. MTs bind motor enzymes that drive many such movements, but MT dynamics can also contribute to organelle motility. Each MT polymer is a store of chemical energy that can be used to do mechanical work, but how this energy is converted to motility remains unknown. Here we show, by conjugating glass microbeads to tubulin polymers through strong inert linkages, such as biotin-avidin, that depolymerizing MTs exert a brief tug on the beads, as measured with laser tweezers. Analysis of these interactions with a molecular-mechanical model of MT structure and force production shows that a single depolymerizing MT can generate about ten times the force that is developed by a motor enzyme; thus, this mechanism might be the primary driving force for chromosome motion. Because even the simple coupler used here slows MT disassembly, physiological couplers may modulate MT dynamics in vivo.

Coupling Factors in Macromolecular Type-IV Secretion Machineries

Type IV secretion systems (T4SSs) are bacterial multiprotein organelles specialised in the transfer of (nucleo)protein complexes across cell membranes. They are essential for conjugation, bacterial-induced tumour formation in plant cells, as observed in Agrobacterium, toxin secretion, like in Bordetella and Helicobacter, cell-to-cell translocation of virulence factors, and intracellular activity of mammalian pathogens like Legionella. By enabling conjugative DNA delivery, these systems contribute to the spread of antibiotic resistance genes among bacteria. These translocons are made up by 10-15 proteins that are analogous to Vir proteins of Agrobacterium and traverse both membranes and the periplasmic space in between in Gram-negative bacteria. Their secretion substrates range from single-stranded DNA/protein complexes to multicomponent toxins and they are assisted by integral inner-membrane coupling factors, the multimeric type-IV coupling proteins (T4CPs), to connect the macromolecular complexes to be transferred with the secretory conduit. To do so, these T4CPs may be required to localise close to the secretion machinery within the donor cell. The T4CP structural prototype is the hexameric protein TrwB of Escherichia coli conjugative plasmid R388, closely related to Agrobacterium VirD4 protein. It is responsible for coupling the relaxosome with the DNA transport apparatus during cell mating. T4CP family members are related to SpoIIIE/FtsK proteins, essential for DNA pumping during sporulation and cell division. These features suggest possible mechanisms for conjugal T4CP function: as a simple coupler between two molecular machines, as a rotating device to pump DNA through the type-IV transport pore, or as a DNA injector, whereby its central channel would function as part of the transport pore.

Development of Novel Coupling Method for Biochemical IC Family and Micro Chemical Devices

We developed a simple and effective coupling method “silicone rubber coupling method” for interconnecting modular micro fluidic devices such as “Biochemical IC Family” proposed by Ikuta. This coupling method utilizes thin silicone rubber films and the holder unit. The biochemical IC chips are stacked up into the holder unit. And reusable thin silicone rubber films formed by a polymer mold are sandwiched between the IC chips. This simple coupler provided a good seal under high pressure (>400 kPa). Moreover, the experiments of this method showed that the maximum leakage pressure increases while the thickness of the silicone rubber gets thin, differing from general sealing technology “O-ring”. Thin coupling part is effective in practical use. This method is useful not only for the biochemical IC chips but also other micro fluidic devices.

A simple coupler to link expert systems with database systems

Over the years, there has been a confluence of concepts, tools and techniques from two diverse areas: artificial intelligence (AI) and database (DB) systems. There are several ways to integrate expert systems (ES) and database systems. This paper surveys the related literature and classifies the integrated systems into four classes: enhanced DB, enhanced ES, coupling of existing ES and DB, and expert database system. A new loose coupling approach (Simple Coupler) based on predefined SQLs is then proposed. Its system architecture and system operations are described. The Simple Coupler is compared with the DIFEAD (Dictionary Interface for Expert Systems and Databases) approach and the commercial ES shell approach on the criteria of the independence of the DB, ES, the complexities and future expansibility. This approach has great practical values because of its simplicity. Finally, this paper reports on two prototypes coupling existing systems: accounting DB & financial ES and medical history database & medical diagnosis system, respectively, in the PC window environment.

Simple output coupler for optically pumped far infrared lasers

A simple output reflector for optically pumped far infrared lasers is presented and successfully tested./aip/

Simple side coupler for coupling between laser diode and single-mode optical fiber

Simple side coupler for coupling between laser diode and single-mode optical fiber

Surface Acoustic Wave Multistrip Components and Their Applications

The multistrip coupler is a directional coupler which operates on freely propagating surface acoustic waves with broad bandwidth and low loss. The applications of simple multistrip couplers with straight strips are discussed together with descriptions and properties of a family of multistrip components that can perform particular operations. Stepped couplers can perform the function of collinear beamwidth compression and a surface-wave "magic T" may be constructed. Bent, U-shaped, and J-shaped structures are considered that may redirect or reflect acoustic beams, and results are presented for a multistrip unidirectional transducer. Complex acoustic circuits may be built up using these elements. A beam may be reflected and stepped to the side by one track width, and both directions of a delay line may be used sequentially to double its capacity. The spurious triple transit signal of a delay line is shown to be virtually eliminated at the expense of an extra 3-dB single transit loss.

Electronic Interaction Theory for Transverse-wave Couplers†

This paper is concerned with a general theoretical analysis of the interaction between transverse waves propagating on a filamentary electron beam and electromagnetic circuits. The class of circuits considered is that for which the transverse electric and magnetic fields are symmetric with respect to the z-axis. Aside from this restriction on the symmetry properties, the analysis is quite general in the sense that the transverse electric and magnetic field components are arbitrary functions of axial distance. Therefore, the analysis is valid for a variety of circuit configurations, ranging from simple coupler circuits, serving the purpose of coupling r.f. power in and out of the beam in r.f. and d.c.-pumped devices, to transverse travelling-wave tubes and multi-cavity klystrons. The transverse field components in pump circuits used for parametric pumping and d.c. pumping of transverse waves are all antisymmetric with respect to the z-axis and are therefore excluded from the present analysis. The material ...