bluuebunny/crossref_metadata_2025_split huggingface dataset:
0.98‐μm ingaas/gaas strained quantum well ridge waveguide lasers
Authors: Okayasu Masanobu , Takeshita Tatsuya , Kogure Osamu , Uehara Shingo 
Published: July 2007

AbstractThe 0.98‐μm InGaAs strained quantum well (QW) lasers have been fabricated. In these lasers, improvement in laser performances such as low threshold characteristic and applicability as a pumping source of Er‐doped fiber optical amplifiers are expected. The measured transparency current density and differential gain coefficient of the strained QW lasers show that they have a higher potential for low‐threshold current operation than conventional lattice‐matched GaAs QW lasers. A threshold current of 3.3 mA has been achieved in a ridge waveguide structure with high‐reflective facet coatings. A maximum output power of 85 mW and an external differential quantum efficiency of 62 percent have also been obtained by anti‐reflective and high‐reflective facet coatings.
A 2.2 gbit/s si bipolar 8 × 8 crosspoint switching LSI
Authors: Yamanaka Naoaki , Kikuchi Shiro , Suzuki Masao , Hirata Michihiro 
Published: July 2007

AbstractA high‐speed 8 × 8 space‐division switching LSI has been developed for video and HDTV switching and broadcasting applications in the future B‐ISDN. The LSI employs a new circuit design and super self‐aligned process technology (SST−1A), and is switched successfully with a bit error rate of less than 10−9at 2.5 Gbit/s using a 29−1 pseudorandom NRZ sequence. Pulse jitter has been limited to less than 70 ps at 2.2 Gbit/s by utilizing a small internal voltage swing (225 mV) employing a differential CML cell. The LSI has an ECL‐compatible interface, −4.0 V and −2.0 V power supply voltages, and power dissipation of less than 997 mW. High‐speed address control memories (ACMs) are integrated mono‐lithically into the LSI, which can operate both synchronously and asynchronously.Using several of these LSIs, a three‐stage switching network prototype system has been demonstrated. This network brings us closer to realizing a large‐scale, gigabit‐order, high‐speed switching network for B‐ISDN.
Spectral linewidth measurement of a GaAs/GaAlAs surface‐emitting laser
Authors: Tanobe Hiromasa , Koyama Fumio , Iga Kenichi 
Published: July 2007

AbstractThe spectral linewidth of a surface‐emitting laser under room temperature CW operation was measured by a delayed self‐homodyne method for the first time. The measured half‐value linewidth was 50 MHz under an optical output of 1.4 mW. This result was comparable to that of a conventional single‐mode stripe laser. When the cavity length was increased to 10 μ with the improvement of the reflectivity of the laser mirror, while maintaining the single‐mode operation, the spectral linewidth could be as narrow as 1 MHz.
Widely tunable optical‐fiber ring laser using high‐performance traveling wave amplifier
Authors: Oshiba Saeko , Nagai Kiyoshi , Kawahara Masato , Kawai Yoshio 
Published: July 2007

AbstractA widely tunable optical‐fiber ring laser is fabricated using a traveling wave amplifier (TWA) and an optical‐fiber loop as the gain medium and the external cavity. The wavelength tuning in the wide range of more than 100 nm is obtained using a high‐performance TWA and a low‐loss external cavity.The TWA is made by anti‐reflection (AR) coated on both facets of a VIPS (V‐grooved inner stripe laser on p‐substrate) laser with residual reflectivity less than 10−4∼ 10−6. The length of the TWA is optimized to obtain high gain peak. The gain distribution of more than 16 dB in the wavelength range of 100 nm and the high gain peak of 30 dB are achieved. As the external cavity structure, the use of a diffraction grating and a bandpass filter, as the wavelength selective elements, are investigated and compared with each other.Hence, it is found that when the filter is used, the wavelength tuning range is about 10 nm wider than that of the grating and the fiber output power over 14 mW is achieved. The laser exhibits a very narrow linewidth of 15 kHz (longitudinal mode) and is believed to be a very useful source in optical communications if it is made to become a single‐mode one.
Gain analysis of multiple quantum well lasers with different well thickness
Authors: Kambayashi Toshio , Hosogane Akira , Enya Mitsuhiro 
Published: July 2007

AbstractThis paper reports a gain analysis of a quantum well laser with multiple quantum well with different well thickness. Since quantum energy levels corresponding to each well appear in a quantum well with different well thickness, it is possible to control to a certain extent the energy distribution of the electrons. This characteristic is used advantageously to control the gain profile of a quantum well laser. In this case, the individual quantum well structures are different and are mutually coupled. Also, since the quantum levels of the second‐ and higher‐order are used, the analysis must be carried out rigorously taking into account the wave nature of the electrons.The laser theory based on the electron relaxation phenomenon has been developed with the wave nature of the electrons considered so that the gain equation is derived. As an example, a structural design has been carried out for low current operation of the oscillation wavelength switch and for flattening the gain profile. Excellent numerical results were obtained. A possibility for new applications of the quantum effect devices is expected.
Theoretical analysis and fundamental characteristics of triplate spiral inductors
Authors: Yabuki Hiroyuki , Makimoto Mitsuo 
Published: July 2007

AbstractThis paper presents a theoretical analysis and examples of triplate spiral inductors. The analysis is based on low‐frequency band transmission line theory, from which three different transmission line circuits are used to model the inductor. After obtaining the circuit impedances for different potential distributions, we deal with the high‐frequency problem using a model where the interline field couplings are simulated as lumped capacitances. Based on these techniques it is possible to investigate basic properties such as the inductances, self‐resonant frequencies and losses.Triplate inductors may be used as three‐dimensional (3‐D) hybrid IC elements in the UHF band (0.3–3 GHz), for example, in broadband matching circuits, various filters, and decoupling circuits for power supply lines.
Capacitive absolute pressure sensors with hybrid structure
Authors: Esashi Masayosi , Shoji Shuichi , Wada Toshitada , Nagata Tomio 
Published: July 2007

AbstractA capacitive pressure sensor with a reference pressure chamber for absolute pressure measurement was fabricated in a hybrid form. This paper describes the summary, fabrication process and characteristics. The fabricated sensor chip has dimensions of 4.5 × 3.4 × 0.9 mm3, a diaphragm area of 1.7 × 1.7 mm2, an electrode area of 1.5 × 1.5 mm2, a diaphragm thickness of 65 μm and a gap of 1.5 μm between the electrodes.The principal characteristics are as follows: (1) since the pressure sensor chip and the capacitance detection IC chip are fabricated separately, the characteristics of both can easily be optimized and the fabrication is rather simple; (2) since the interior of the reference pressure chamber is hermetically sealed, the effect of humidity can be minimized; (3) since a thin p+ silicon cap is sealed using anodic bonding on the hole in the glass of the reference pressure chamber side, the terminal can be removed from the electrode on the glass side with a minimum parasitic capacitance to the silicon; and (4) the temperature characteristics of the pressure sensor can be minimized by changing the power supply voltage of the capacitance detection IC. The output sensitivity of the hybrid pressure sensor was −9.22 kHz/kgf/cm2, the nonlinearity was −5.3 percent F.S., the thermal zero shift was −3.1 percent F.S. (5 to 45d̀C) and the thermal sensitivity shift was 3.8 percent F.S. (5 to 45d̀C).
A method of recording holograms by means of multiple embossment: Experiment using an improved stamper
Authors: Ando Shigeru , Nakazawa Takaki , Sekine Seishi , Hoshi Katsuhiro , Mita Motohito 
Published: July 2007

AbstractThe results of the authors' previous experiment on multiembossed holograms using a stamper whose master model is an echelette grating revealed a requirement for signals (molded grating grooves with different orientation angles and constant spatial frequency) with relatively uniform diffraction efficiency and weakened unwanted diffraction. The requirement can be written as d'/d >> 1 where d' is the groove width and d is the grating constant [1].In this paper, the molding of grating grooves using stampers (d'/d = 0.12) of square cross section which satisfy the condition and the recording of the multi‐embocsed hologram have been tested.The uniformity of diffraction efficiency within one decade and the noise ratio (the ratio of the first‐order diffraction efficiencies of the unwanted diffraction and the signal) below 0.6 have been obtained with a multi‐embossed hologram (eight times). These characteristics are obtained by varying the value of the pressure when the temperature of the stamper is constant and are suited to the typewriter input type of recording. In addition, a suggestion for a stamper which is applicable to holographic memory for information retrieval is given (d'/d less than about 0.06).
Optical characteristics simulation of TFT addressed liquid crystal display
Authors: Ono Kikuo , Tanaka Takeshi , Konishi Nobutake , Ohwada Junichi 
Published: July 2007

AbstractA simulator has been developed which can calculate optical characteristics of TFT addressed liquid crystal displays (LCDs) such as optical threshold voltage and contrast ratio. Then the performance of LCDs addressed by amorphous silicon TFTs are analyzed. This simulator has advantages of obtaining accurate solution of optical characteristics, which previously had been obtained only by measurements, by giving TFTs dimensions and their characteristics, and LCD's driving conditions as the input data.Furthermore, the simulator has also taken into consideration the effects of voltage distortion due to line resistance and capacitance, and voltage dependence of gate source parasitic capacitance in addition to temperature dependencies of threshold voltage and mobility of TFTs, and liquid crystal characteristics on LCD performance to obtain more accurate solution. It was found that calculated characteristics agreed well under a practical temperature range from 0 to 60°C with the measurements obtained for large‐area 10‐inch diagonal TFT‐LCDs. This agreement verified the simulation validity.
A high‐speed BiCMOS gate array using bicmos gate circuit featured by darlington buffer
Authors: Suzuki Masao , Nagatsuma Tadao , Sano Eiichi , Kobayashi Yoshiji , Yamaguchi Chikara 
Published: July 2007

AbstractWe designed and built prototypes of 2.1‐K gate arrays which are compatible with ECL bases on the 1‐μm design rule of CBiCMOS process technology. We compared various basic gates based on external circuit formulation. We adopted new BiCMOS circuits with Darlington buffers which proved to have fastest responses. Through this circuit we can obtain the speed‐up of the dynamic response and a sufficient dc operational margin. As a result of manufacturing prototypes, we realized the delay time of 236 ps for two input AND gates with load capacitance of 0.4 pF and 13 μW/MHz for the power consumption. We achieved a super‐high speed of 40 ps/μF for the dependance of the speed on its load capacitance.
A 70‐MHz, 32‐bit BiCMOS processor
Authors: Tanaka Shigeya , Hotta Takashi , Iwamura Masahiro , Yamauchi Tatsumi , Bandoh Tadaaki , Hotta Atsuo , Iwamoto Seiji , Adachi Shigemi 
Published: July 2007

AbstractA 70‐MHz, 32‐bit BiCMOS processor has been developed. This paper describes the architecture and the high‐speed technology, mainly the arithmetic unit, of the very‐high‐speed BiCMOS processor. This processor includes a 32‐bit ALU, register file with four ports, arithmetic unit composed of ±32‐bit barrel shifter and so on, ROM storing microprograms, memory management unit, cache controller, and clock generator. The chip integrates 529,000 transistors (including bipolar transistors of 1.5 percent) within 12.98 mm × 12.98 mm chip. The BiCMOS circuit technology is applied to the register file, arithmetic circuit, clock generator, and so on, to achieve the 70‐MHz BiCMOS processor under typical conditions. Thus, the effectiveness of employing the BiCMOS technology for very‐high‐speed digital LSIs, such as microprocessors, has been verified.
Liquid crystal rear projection display for Hi‐vision
Authors: Miyatake Yoshito , Muraji Tsutomu , Takeda Mamoru , Tsuda Keisuke 
Published: July 2007

AbstractThere is an increasing demand for development of a display for large‐screen Hi‐Vision pictures that is compact and has a lightweight design, high resolution, and high picture quality; this is a Hi‐Vision display that may be enjoyed in the home.To create a Hi‐Vision display suited for household use, a reflective‐type TFT liquid crystal panel was developed having 1,360,000 pixels in a 2.3‐inch screen, a compact optical system using three liquid crystal panels, three projection lenses, and a circuit system for wideband video signals. A prototype of the liquid crystal rear projection display also was manufactured.This prototype has a 40‐inch large screen, yet it is compact and lightweight, measuring only 45 cm in depth and 85 cm in height, and weighing a scant 50 kg. In addition, it possesses high resolution, applicable to the Hi‐Vision system. In this experiment, the liquid crystal projection display was established to be the most hopeful candidate for the household Hi‐Vision display.
Simultaneous measurement of carrier mobility and lifetime in hydrogenated amorphous silicon films
Authors: Homma Kazuaki , Motohashi Mitsuya , Murayama Yuuki , Fukami Toyoji 
Published: July 2007

AbstractIn the development of various photoelectric conversion devices using hydrogenated amorphous silicon (a‐Si:H) thin films, the carrier mobility and lifetime are important physical parameters associated with device characteristics. Especially, in the examination of film quality for the purpose of improving the device performance, it is extremely important to know the carrier mobility and lifetime in the same device.However, conventional methods have a disadvantage in that these properties must be measured separately in different device structures. Therefore, in this work, noting the process in which the carriers generated by an optical pulse onto the a‐Si:H film decay both by extraction due to an electric field and by recombination, a new method for simultaneously measuring the carrier mobility and lifetime in the same device is proposed. As a result of examining the experimental data, this measurement method has been found to be effective for the carrier mobility and lifetime measurement of highly resistive thin‐film material with dispersive conduction.
Formulation of quantum effects by using a complex‐valued equivalent circuit
Authors: Ohtani Naoki , Nagai Nobuo , Suzuki Masakiyo , Miki Nobuhiro 
Published: July 2007

AbstractDue to the miniaturization of electronic devices, the establishment of the formation of quantum effects and the design methodology of quantum effect devices such as superlattices is becoming important.In this paper, it is attempted to consider the one‐dimensional scattering problem such as the scattering of an electron wave at the step potential and the tunneling effect at the potential barrier by a circuit theory. In other words, noting that the Schrödinger equation with time‐dependent terms contains complex coefficients, imaginary resistances, which are lossless elements, are introduced into its equivalent circuit.As a result, it has been shown that the circuit corresponds to a lossless transmission line when the electron energy is larger than the potential and that the circuit can be represented by a lumped constant circuit using reactant devices inside the potential barrier. In addition, if the electron scattering phenomenon corresponds to the circuit voltage, the conservation law of the probability can be represented by the effective power, and the transmission circuit theory is effective for the quantum effect phenomena. Furthermore, it has also been confirmed that the resonant tunneling effect and the eigenenergies of the single quantum well can be calculated by our method.
Realizing high resolution in surface‐discharge AC plasma displays
Authors: Uchiike Heiju , Kubo Akira , Harada Shigeki , Kanehara Takao , Fukuda Masanori 
Published: July 2007

AbstractThis paper investigates surface‐discharge ac plasma display with high resolution. Even when high resolution was achieved by using an electrode structure with a wide gap between the upper electrodes, sufficient memory margin, high luminance, and high luminous efficiency were obtained. In a high‐resolution panel with a cell pitch of 0.15 mm, the luminance and luminous efficiency were 200 cd/m2 and 0.14 1m/W, respectively.It was found that by optimizing the distance between the MgO layer and phosphor layer, the luminance and luminous efficiency could be improved.
A study on measurement and simulation for the propagation characteristics of through‐hole
Authors: Maeda Shuji , Yoshida Norinobu , Fukai Ichiro 
Published: July 2007

AbstractWith the recent rapid advance in electronic technology, electronic components have become smaller, lighter and higher in performance. In connection with this trend, there has been increased use of the high frequencies due to increased speed of the devices. Under such situations, the interconnects between the electronic devices must be treated as strip lines. Especially, the through‐hole with a three‐dimensional structure indispensable for high‐density interconnects has nonnegligible effects on the circuits. Hence, the need for an analysis of its characteristics is acute.In this paper, to derive quantitative propagation characteristics of the through‐hole, a three‐dimensional electromagnetic field simulation of such a structure was carried out using the spatial network method and the results were compared with experimental data. It was confirmed that the simulated values of the time domain response and the frequency characteristics showed good quantitative agreement with the measured data. As a result, the validity of the simulation and the basic propagation characteristics of a through‐hole were confirmed.
Design and performance of a surface potentiometer
Authors: Imada Hiroshi , Kiwaki Hisatomo 
Published: July 2007

AbstractThe electrostatic surface potentiometer has the feature that the distance compensation effect is included and the fast transient phenomenon can easily be observed. On the other hand, the noise is increased when a wideband is realized while maintaining a high input resistance. When a low potential is to be measured or the area of the measuring electrode is decreased aiming at a high resolution, a limit of performance is produced. The investigation of this point is not yet sufficient.This paper derives the formula for the bandwidth of the amplifier, which is needed in the design and construction of such a surface potentiometer. Using the angular frequency and the output noise voltage as the parameters, a formula is derived which relates the amplification A to the capacitance between the sample and the sensing electrode. Those results were verified by experiment. The operating region for A and m (which is the ratio between the capacitance between the sample and the sensing electrode, and the input capacitance of the potentiometer) is useful in the design and construction of the potentiometer.
Optical recording properties and structure of new silver metallic particles system
Authors: Hayashi Yoshio , Ogawa Shuichiro 
Published: July 2007

AbstractIt was found that a new type of reflective optical recording material could be formed by the thermal reduction of organic silver salt. In this recording material, metallic particles 30 nm in diameter concentrate near the surface of a hydrophobic binding agent and form island‐like structures. The reflectivity can be varied from 20 to 75 percent by controlling the compositions of organic silver salt/reducing agent/binding agent and the condition of the thermal treatment.This material is capable of recording optical pulses from a semiconductor laser with a wavelength of 830 nm, power of 10 mW and pulsewidth of 1 μs at a length of 1 μm. Using the same type of laser (830 nm, 10 mW), a CN ratio of 45 dB can be achieved when the recording speed is 50 cm/s. Since this recording material was formed by using a hydrophobic binding agent, it is stable under high‐temperature/high‐humidity ambient.
Ladder‐type microwave power divider/combiners
Authors: Fukui Kiyoshi , Nogi Shigeji , Sanada Atsushi , Oishi Seiji 
Published: July 2007

AbstractAs a new power divider/combiner, a wideband microwave ladder‐type power divider/combiner with simple multiple branching structures is proposed in which probe pairs are provided to waveguides in a ladder shape. Based on the equivalent circuit, a design formula for a complete power division/combining is derived as well as the optimum coupling phase shift in the divider and combiner in the construction of a divider/combiner system. The frequency characteristics of the transmission efficiency of a divider (or combiner) alone and a divider/combiner system are analyzed numerically in terms of the admittance value of the probe pair so that the upper limit of the relative bandwidth of each stage (which is equal to the number of probe pairs) is derived. In the × band, 1–3 stage (2–6 port) divider/combiners were constructed.By means of the experiment of the transmission characteristics of the divider (or combiner) alone and the divider/combiner system, broadband characteristics were confirmed which agree well with the analytical results. In the case of a three‐stage ladder‐type divider/combiner, the reduction of the efficiency in the range of ±0.5 GHz from the center frequency (9 GHz) was less than 0.36 dB in a divider alone and less than 0.48 dB in the overall characteristics of the divider/combiner system. Further, isolation was studied theoretically and experimentally. In addition, the measured results were explained. It is demonstrated that the isolation can be improved without degrading the broadband characteristics by reducing the susceptance value of the probe pair.
Lift‐off fabrication of fine cu patterns with a high aspect ratio
Authors: Yuitoo Isamu , Moriwaki Eijin , Shiiki Kazuo , Yamada Kouji 
Published: July 2007

AbstractRecently, the pattern width in semiconductor devices has become as narrow as a submicrometer. As the pattern width decreases, the current density increases, thereby causing the breakage of the conductors due to electromigration and excessive heat generation.In the inductive thin‐film magnetic head used for the magnetic disc system, the number of wire windings in a coil should be high and the resistance should be low to achieve high output and low noise. To achieve these requirements, the aspect ratio of the conductor should be high and the conductor should be made of copper (Cu).The purpose of this study is to pattern fine Cu conductors with a high aspect ratio using the lift‐off technique. In the lift‐off technique, it is important to form a thick resist pattern with inverted‐trapezoidal cross section. In this study, image‐reversal photoresist was used and the conditions of exposure, heat‐treatment, and development were optimized to obtain a frame suitable for lift‐off. As a result, it was found that the Cu conductor with a pattern width of 1 μm and an aspect ratio over 2 could be fabricated.
Frequency and phase control of light in coherent optical communication systems
Authors: Kikuchi Kazuro 
Published: July 2007

AbstractCoherent optical communication systems require the precise control of frequency and phase of a semiconductor laser used as transmitter or local oscillator by means of external circuitry. This paper first describes the necessity of frequency and phase control and reviews various control methods. Next, the importance of suppression of frequency‐phase noise due to the control of the frequency and phase of a laser is discussed.