摘要:

AbstractAs devices are miniaturized and device operation speed increases by the progress of fine fabrication technology, the problems associated with interconnections such as interconnect delay and crosstalk are becoming important. Therefore, an optical connection as a new interconnect technique to solve these interconnection related problems is becoming noticed. On the other hand, three‐dimensional LSIs are again becoming noticed as an LSI to overcome the limitations of high integration and to incorporate new functions such as parallel processing function. Consequently, this paper examines the possibility of LSI with new function surpassing the present LSIs by combining the optical interconnection and three‐dimensional LSIs by combining the optical interconnection and three‐dimensional LSI. As an example of this kind of LSI, a three‐dimensional optically coupled common memory is described and the performance improvements are specifically shown by combining the optical interconnection and three‐dimens

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760201

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe fundamental research on process technologies for three‐dimensional optoelectronic integrated circuits (OEIC) conducted at Optoelectronics Technology Research Laboratory (OTL) is reviewed. These process technologies consist of atomically controlled epitaxy and thein situpattern formation of III—V semiconductors.For atomically controlled epitaxy, various surface analysis techniques are utilized in combination with molecular beam epitaxy (MBE). Thein situpattern formation is performed using a thin oxidized layer of GaAs in an ultrahigh vacuum (UHV) multichamber system. This patterning is based on thein situelectron‐beam (EB) induced C12 etching of the photooxidized GaAs layer.On the basis of the foregoing result, the process technologies for the future three‐dimensional OEIC are di

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760202

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

年代:1993

数据来源: WILEY

摘要:

AbstractA high‐power pulsed solid‐state laser for single‐mode oscillation is considered to be an important device in the new coherent optoelectronic fields such as super‐high‐resolution optics and heterodyne lidar. The injection seeding method has been utilized for single‐mode operation of high‐powerQ‐switched lasers but the analyses of the basic characteristics and detailed experimental evaluation have not been carried out.In this paper, the conditions for single‐mode oscillation are analyzed using the multimode oscillation model and basic laser equations. Then the seeding characteristics are investigated using a laser diode (LD) pumped tunable wavelength single‐mode Nd : YVO4microchip laser for the master laser and a pulsedQ‐switched Nd : YAG laser for the slave laser. As a result, it was found that single‐mode operation could be realized by the extremely low power of 0.9 μW which was close to the theoretical limit.In about 140 μm injection, the detuning width was 282 MHz which was close to the longitudinal mode separation. A seeding bandwidth of 71 GHz, which is almost half the fluorescence spectrum width

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760203

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe analysis of resonant electrical length and unloadedQfor the miniaturized dielectric coaxial stepped impedance resonator (SIR), used often in diplexers of portable radio telephones, is performed usually with the assumption of only fundamental TEM mode.In this paper, finite element TM mode analysis is performed and optimum structure design of SIR is shown which makes the ratio of unloadedQto the resonant electrical lengthkL(Q/kL) maximum. As a result of analysis, it is found that the location of the step to minimize resonant electrical length is about 40 percent of the axial length from the open end of SIR.The ratio of unloadedQand resonant electrical length varies rather slowly when any of the structure parameters are varied around the optimum value. This fact shows that no high precision in the design of structure parameters is required. Moreover, providing taper at the step position in SIR, the resonant electrical length can be increased by a few percent.It is shown also that the present analysis is useful for the design of square‐shaped SIR which is a simple and practically used structure for diplexer

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760204

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

年代:1993

数据来源: WILEY

摘要:

AbstractA novel combined integral equation, which is adaptable to the analysis of a general electromagnetic field in a cylindrical structure, is proposed. The unknown quantities of the equation are the transverse electromagnetic field components and the equation is analyzed numerically by the boundary element method. The combined integral equation does not have the difficulty arising from the nonphysical solutions which have been troubled conventionally. In addition, the integral equation does not contain spatial derivatives of the unknown quantities. The coefficient matrix of the matrix equation obtained by the application of the boundary element method is square and is hence suitable for numerical analysis.In this paper, first the combined integral equation for unknown transverse electromagnetic field components are derived. The uniqueness of the solution is proven. Further, the integral equation is analyzed numerically for actual examples by the boundary element method so that the validity and effectiveness of the method are verified.

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760205

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

年代:1993

数据来源: WILEY

摘要:

AbstractIn this paper, the modified step segment method (MSSM) is proposed as the highly accurate procedure in the analysis of the diffusion‐type optical waveguides and its accuracy is discussed theoretically. An optical directional coupler with exponential refractive index distribution is treated for which the numerically determined guided modes are compared with the analytical ones. As a result, it is found that the effective refractive index determined by MSSM agrees with the theoretical one and the error is less than 10−6.It also is understood that the convergence of the method is much better than that of the step segment method (SSM). Comparison of the present method with the linear segment one (LSM) indicates that the overflow can be avoided together with a considerable shortening of the CPU time. Therefore, it is concluded that the present method is very effective in the analysis of the diffusion‐type optical waveguides with very high acc

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760206

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

年代:1993

数据来源: WILEY

摘要:

AbstractA design method of a dielectric multilayer bandpass filter for optical‐communication is proposed, and its feasibility is demonstrated for an example of the design.The design procedure is to replace each resonator in a specifiedLCbandpass filter by a corresponding dielectric multilayer resonator. ThisLCbandpass filter is obtained from anLClowpass prototype through a frequency transformation. New structures of a dielectric multilayer resonator are proposed, and the equations necessary for the design are derived. A method to correct a design error due to excess phase also is discussed.With the present design method, an arbitrary polynomial characteristic (Butterworth, Chebyshev, and Bessel, etc.) can be realized as a dielectric multilayer bandpass filter. A good agreement is found between the designed and actual performance for a narrowband bandpass filte

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760207

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe surface acoustic wave (SAW) changes its propagation characteristic if the region above the propagation surface is altered. This phenomenon can be used for realization of an SAW sensor. The Rayleigh mode known as a general SAW can be used as a gas phase sensor. If, however, the propagation surface is loaded with liquid, a longitudinal wave is radiated into the liquid and the Rayleigh wave decays. Hence, this wave cannot be used for a liquid sensor.To realize a liquid sensor, the SH mode must be used in which the particle displacement is normal to the propagation direction and parallel to the propagation surface. It has been reported that the SAWs propagating on piezoelectric crystals such as 36° rotated Y‐cut X propagation LiTaO3and X‐cut 150° propagation LiTaO3are SH‐mode SAWs (SH‐SAW).In this paper, it is found theoretically and experimentally that the shear horizontal‐ (SH‐) SAW devices using these piezoelectric crystal cannot only detect the mechanical effects such as the viscosity of the liquid and the mass loading in the liquid but also the electrical effects such as the permittivity and conductivity of the liquid. By way of comparison with other liquid sensors using high‐frequency ultrasonic devices, the characteristics of the SH‐SAW sens

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760208

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

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper describes a circuit configuration for a biquad filter which utilizes the second‐generation current conveyors (CC II) and is capable of synthesizing an arbitrary second‐order transfer function.The circuit is composed of a subblock circuit with two positive CC IIs and a differential input circuit with two positive CC IIs.The subblock circuit realizes a lowpass, high‐pass, and bandpass filter. Combining this with the differential input circuit produces an all‐pass and notch filter.Each filter has a high input impedance because its input is the Y terminal of the CC II and can be cascaded without a buffer. The quality factorQof the filter is determined by a ratio of passive elements, and its sensitivity to the passive element values is less than 0.5. These characteristics make the filters suitable for monolithic IC implementations. The effects of CC IIs voltage error ϵvand current error ϵion the filter characteristics were studied. It was found that the center frequency ωois independent of these errors,Qis affected only by ϵi, and the gain factor is a function of both ϵvand ϵi. Each filter was prototyped and was verified to operate

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760209

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

年代:1993

数据来源: WILEY

摘要:

AbstractTo prepare constituent materials applicable to a Cu metallization technology of Si‐LSI, the preparation conditions of Cu‐Ti intermetallic compound films have been examined and the thermal stability of the Cu/CuTi2/Si contact structure has been studied using CuTi2compound films as a diffusion barrier. As a result, a stoichiometric intermetallic compound film of CuTi2was prepared successfully at a substrate temperature of 300°C by dc sputtering using a composite target with an area ratio of Cu : Ti = 51 : 49.From the study on the CuTi2/Si contact structure, it was revealed that the CuTi2phase was stable up to 500°C and a thin interface layer of Ti silicide was formed at the interface of CuTi2/Si but the excess diffusion and/or reaction have not been observed. Ti silicide layer formed at the interface is believed to be effective for low contact resistance. To examine whether or not CuTi2films are suitable for Cu metallization technology, the thermal stability of Cu/CuTi2/Si contact structure was examined. It was found that the structure is successfully stable up to 500°C and is useful for Cu metallization technology. The reason is believed to be as follows: the interface of Cu/CuTi2is in the chemical equilibrium state and CuTi2itself is a stable compound phase at high temperatures in the Cu‐Ti allo

ISSN:8756-663X    

DOI:10.1002/ecjb.4420760210

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

年代:1993

数据来源: WILEY