摘要:

AbstractOptical‐disk pickup heads have been constructed with microoptics. Great improvement in producibility and reduction of weight and size are expected by replacing the pickup head with integrated optics. Such an integrated optic device can be constructed by a focusing grating coupler (FGC) which focuses an optical guided wave onto a point in space. This paper describes the theoretical and experimental examinations of the fundamental characteristics of the FGC for the integrated optical disk pickup device. The theoretical analyses show the feasibility of an FGC having a focus spot width larger than the diffraction‐limited value only by 3 percent and the efficiency of 60 percent, by optimizing the device parameters. The analyses of the imaging of the optical system show that the tracking error and the focusing error of a disk can be detected as the displacement of the focal point of the back‐coupled optical guided wave. By fabricating FGCs by an electron‐beam etch method, the focus spot widths were measured to be 3 μm for the laser diode and 1.4 μm for the He‐Ne laser, while the diffraction‐limited values are 1.4 μm and 1.1 μm, respectively, and the imaging relation was confirmed. The efficiency was measured to be 40%. It is necessary for the pickup operation and was confirmed experimentally that the reflected light from the focal plane is coupled back into the waveguide

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractWhen Bi4Ti3O12is viewed as a piezoelectric material, since the direction of the spontaneous polarization is limited in two dimensions, it is necessary to perform grain orientation. In this paper, as a method for the grain orientation at room temperature, a cold‐uniaxial pressing method is considered, and the fabrication method of Bi4Ti3O12grain‐orientation ceramic is examined. Furthermore, the electrical characteristics of the obtained grain‐orientation sample are also examined. This method performs grain orientation by utilizing the shape anisotropy of the ceramic powder. Therefore, first, the relation between the firing process and the grain growth is examined for normal firing sample. Next, the orientation sample is obtained by applying a uniaxial pressing and a main firing to the obtained plate‐like primary particles. As a result, it has been found that the orientation by this cold‐uniaxial pressing method is due both to the orientation of primary particles during the deformation by uniaxial pressing, and also to the grain growth during the main firing. It has also been found that oriented samples comparable to the hot‐working method can be obtained by this method in terms of grain orientation and electrical char

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractSolid thin‐film energy‐transfer dye lasers (thin‐film ETDL) were developed by doping donor‐acceptance dye pairs in the polymer waveguide. Many types of thin‐film ETDL having a slight degradation of the pumping light were obtained. As a result, the wavelength range of the ETDLs became very wide covering almost the entire region from near UV to near IR. The thin‐film cascade ETDL operation was materialized on the first attempt. The spectral narrowing and the tuning of the solid‐film ETDLs are easily obtained by using the DFB operation. The results show the possibility of making a practical compact laser source with a variab

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractIt is known that the high‐rate deposition of magnetic thin‐films by using the magnetron sputtering method is very difficult since the target shields the magnetic field. We carried out the high‐rate deposition of Co‐Cr films by using the compressed magnetic‐field (CMF) magnetron sputtering method in which the magnetic pole does not touch the target. This paper describes the features of the apparatus, and the investigation of the orientation of thecaxis and the difference in the magnetic characteristics, from the changes of the gas pressure of Ar, the temperature of the substrate, and the deposition rate of the film. The results show: (1) the deposition rate of the film was 0.26 μm/min maximum showing the possibility of a high‐rate deposition of the films; (2) the lower the gas pressure, and the higher the film deposition rate, the better the film characteristics; (3) the temperature of the substrate has a slight effect on the orientation, so that the films can be prepared at a temperature as low as 100°C; and (4) the smaller the half width of the rocking curve, the greater the coercive force. Finally, the CMF‐magnetron sputtering method is very effective in preparing perpendicular‐magnetization Co‐Cr films at a low temperature and a hig

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractDiamond‐like carbon (DLC) films were deposited on silicon wafers by hydrogen gas reactive dc‐sputtering of graphite and fabricated MIS diodes. ESCA chemical depth profiles showed that almost no impurities such as oxygen and nitrogen were present in the bulk of DLC films. In the interfacial region between DLC and Si substrate, a small amount of Si‐C bonding as well as natural oxide of silicon were detected. It is found that the 1st‐derivative spectrum of C‐KLL Auger line in ESCA from the DLC film surface was very similar to the C‐KLL AES spectrum from natural diamond. This suggests that DLC film has a fairly diamond‐like tetrahedral sp3C‐C bonding configuration. The C‐V curves of the Hg/DLC/Si MIS diodes showed accumulation, depletion and inversion characteristics. The charge trapped in DLC film and the interface state density distribution as a function of the surface potential were obtained first. Both the amount of trapped charge and the C‐V hysteresis were considerably smaller compared to an Si3N4/Si diode.The interface state density curve exhibits a “U” shape and the minimum density was less than 3 × 1010/cm2/eV in the vici

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractTo fabricate submicrometer transistors practical for LSI by conventional photolithography with a minimum pattern width of 1.5 μm, a self‐aligned process using a selective etching of polysilicon technology (SEPT) has been developed. Compared with the formation of fine patterns by side etches of overhangs, this process, using an oxide thickness and a diffusion distance as a pattern width, has a high accuracy and reduces the variation of the base voltage (VBE) which becomes an important characteristic when the emitter size is reduced by a self‐alignment technique. In this method of self‐aligning the base contact and the emitter, a submicron transistor with emitter width of 0.8 μm, base‐emitter spacing of 0.4 μm, and the base contact width of 0.3 μm can be fabricated with a mask pattern of 1.5 μm width. By the reduction of the active region, the junction capacitance and the base resistance which affect the high‐speed performance have been reduced drastically. A 25‐stage, 3‐input ECL ring oscillator designed with practical rules of 1.5 μm minimum pattern width and 4.5 μm interconnection pitch has shown a delay of 95 ps (ICS= 0.78 mA). Since this method has a high‐dimensional accuracy and reduces theVBEvariation which becomes an important characteristic for LSI, it can be u

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractWhen a thin metallic film electrode deposited on the surface of a glass substrate is heated, a change is produced in the refractive index due to the thermooptic effect in the substrate, which is proportional to the temperature distribution. Due to the gradient of the refractive index produced below the electrode, the laser beam passing through the substrate is deflected toward the electrode. This paper presents a simple technique for the measurement of the refractive‐index change below the electrode, which utilizes the deflection of laser beam. The method is applied to fused silica, Pyrex glass, Tempax glass and B‐270 glass and the measured results are shown. Together with the increment of the refractive index, a constant determining the temperature distribution of the substrate and the temperature of the electrode are also measured. To verify the validity of the method, the thermal coefficient representing the temperature dependence of the refractive index is calculated from the measured refractive‐index increment and the electrode temperature. The result for the fused silica is compared with the previously reported value. As a result, it is seen that the value obtained by the proposed method agrees well with the published value. A discussion is also made on the accuracy of the measured v

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractA new elastic convolver is proposed in which a nonlinear interaction of surface acoustic waves (SAW) on multiple waveguides is used. Theoretical and experimental investigations are carried out. When two SAWs with angular frequency of ω and wavenumber of β, and with ω and‐β propagate in opposite directions on N waveguides, the parametric mixing phenomenon generates a SAW with a sum frequency traveling in the direction normal to the waveguide. The generation efficiency increases: (i) when the width of one of the waveguides is one‐half the wavelength of the sum frequency SAW; (ii) with the numberNof the waveguides with the maximum occurring atN= 8 ∼ 10; and (iii) with the larger velocity difference (ΔV/V). Generation of the sum frequency SAW is possible only with the guided mode of SAW. The present convolver can be matched easily with the external circuit, because the convolution output is extracted with an interdigital elect

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractA switched capacitor (SC) power supply with a low output power can be made highly efficient, small and lightweight. The finite element method is a numerical technique superior in adaptability and convergence; however, its application to electronic circuits is yet to be explored. In this paper, the finite element method is used as a time domain algorithm for transient and steady‐state analysis of a step‐down, low‐output SC power supply. In the case where the on‐resistances of P‐channel MOS switches and N‐channel MOS switches are not equal, such transient characteristics as the overshoot and rise time of the output voltage and such steady‐state characteristics as the steady output voltage, efficiency and ripple voltages are analyzed. It is found that the parasitic inductance of the wiring reduces the power supply efficiency. Although the results agree well with those by the Hamming method, the computation time is shorter in the finite element method. It is confirmed that the finite element method is efficient for analysis of the problem described by st

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper discusses a highly precise method of measurement for the attenuation of a coaxial cable using a short test‐piece. The proposed method is used to compose an open‐ended resonator by the coaxial cable and to determine the attenuation from the resonant characteristics. To realize a highly accurate measurement using a very short test‐piece, the end effect of the cable must be corrected. A correction formula is presented, which by experiment, is verified as useful. The end effect in the proposed measurement is one order of magnitude less than that in the short‐circuit resonant method, which has been used in the past as the method measurement for the attenuation of the short test‐piece cable. It is shown that if the test‐piece is longer than a certain value, the measurement can be performed without considering the end effect. The measurement accuracy of 0.2 percent and the repeatability of 0.1 percent are realized by the proposed method. The upper limit of the cable attenuation that can be measured by the proposed method is discussed. When the resonant characteristics are measured by the half‐amplitude width, the upper limit is 7.6 dB, indicating that a wide range of attenuations can be measured. The proposed method is then applied to the measurement of the attenuation‐pressure characteristics of the submarine coaxial cable verifying the usefulnes

ISSN:8756-663X    

DOI:10.1002/ecjb.4420700110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1987

数据来源: WILEY