摘要:

AbstractRecently, it has been recognized that organic materials have a very large nonlinear optical constant compared with non‐organic materials (e.g., KDP and LiNbO3). It has been known that 2‐methyl‐4‐nitroaniline (MNA), among them, has an extremely large SHG tensor, although this has a disadvantage in that thed11component cannot be matched in phase in the bulk crystal state. When an MNA single‐crystal made by using the vapor‐phase method and shaped in a thin parallelogram, is set on a tapered slab‐type thin‐film waveguide appropriately, and the fundamental wave is applied as a TE wave, it is possible to match the phase of the fundamental wave and the phase of the second harmonic wave at a certain waveguide thickness. Since the refractive index of the MNA is greater than that of the slab‐type waveguide film, an SHG is observed at the resonating film thickness when the high‐refractive‐index top layer is used. The observation of the second harmonic (0.532 μm) was made by using an Nd:YAG pulse laser (1.064 μm) for the fundamental wave. The phase matching point was examined from the dispersion curves which was calculated from the waveguide structure parameter. The results show that this phenomenon is the conversion from the TE first of the fundamental wave to the TE second of the secondary harmonic. The efficiency of the MNA observed was not great since the overlapping of the two

ISSN:8756-663X    

DOI:10.1002/ecjb.4420680501

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe effect of winding configuration on leakage inductance of a toroidal core transformer for electronic pulse‐drive circuits is investigated. Theoretical expressions for the effect of wire diameter, conductor spacing of primary and secondary windings, winding pitch, number of turns and core dimensions are derived. It is found that: (1) winding capacitance can be reduced without increasing the leakage inductance by applying an insulation coating to the core; (2) the leakage inductance is simply proportional to the number of turns; (3) a core of square cross‐section can reduce the ratio of leakage inductance to excitation inductance; (4) leakage inductance decreases with decreasing conductor spacing of the pair wire and with increasing diameter; (5) and the leakage inductance decreases with decreasing winding pitch and, in the case of a dense winding, it is less than that of a sparsely wound coil by as much as a value proportional to log (4/3). The experiments in which the above results were obtained were in good agreement with calculated val

ISSN:8756-663X    

DOI:10.1002/ecjb.4420680502

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

年代:1985

数据来源: WILEY

摘要:

AbstractExperiments have been carried out to obtain a method different from the conventional method, to optically read out the signal recorded on a magnetic recording medium by transferring it to a magnetic garnet film. This method forms straight parallel stripe magnetic domains in the garnet film, and the read‐out is done by varying the domain width using the stray field from the recording medium.Static transfer and dynamic readout experiments have been done using a garnet film with straight stripe magnetic domains with the domain width of 2.25 μm and the domain period of 4.5 μm. Statically, the transfer of the signal with a wide range of recording wavelength 5 μm‐200 μm was done without any domain disturbances. Also, there were no unnecessary domains between the transferred tracks. On the other hand, when the magnetic sheet disk was rotated with a relative speed of 50 m/s, a stable readout of the signal with 0.25 MHz to 10 MHz was possible using a laser beam with a spot radius of 5 μm.These experimental results indicate that the new transfer method is suitable for a signal read‐out of narrow track recording, and that it is superior in high‐speed response. Further, from the analysis of the readout model, a further improvement of the readout characteristics is shown possible by reducing the

ISSN:8756-663X    

DOI:10.1002/ecjb.4420680503

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

年代:1985

数据来源: WILEY

摘要:

AbstractThin‐film ZnS:TbF3was deposited by sputtering and a thin‐film electroluminescent panel having a display area of 34 mm × 34 mm was fabricated. The brightness distribution was investigated and film thickness variation and distribution of Tb luminescence centers were studied in conjunction with the brightness. It was found that uniformity of the brightness increases as the applied voltage increases and frequency decreases. Relative brightness deviation (Bmax‐Bmin,)/Ba, whereBmax,BminandBaindicate maximum, minimum and average brightness, respectively, of the film was 13 to 23% when it was driven by 5 kHz, 40‐V voltage. It was observed that brightness distribution depends on film thickness of the ZnS:TbF3layer and that the thinner part has higher brightness. Based on the consideration that thickness variation causes irregular field intensity as well as the conduction charge distribution, and results in brightness variation, we calculated the brightness deviation and found that it agreed well with the experimental results. It was also demonstrated that Tb ions were scattered uniformly in the sputtered ZnS film, which was proved to have uniform luminescence center dist

ISSN:8756-663X    

DOI:10.1002/ecjb.4420680504

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

年代:1985

数据来源: WILEY

摘要:

AbstractAn edge‐junction type nm (nanometer) bridge is fabricated which has bridges on the joint of the edges of two Nb films. Each nm bridge has an effective length of less than 50 nm, width about 2 μm, and thickness from 30 to 60 nm. To make a good edge‐junction type nm bridge, it is necessary to form a sharp edge on an Nb film. For this purpose, dry‐etching with a teflon holder in an He gas was used. Voltage steps up to about about 100 μV induced by a microwave were observed in the fabricated device, and the value ofIORngreater than 50 μV was obtained. By measuring the threshold characteristic of a DC‐SQUID consisting of this nm bridge, it was confirmed that the current‐phase relation of the bridge is sinusoidal. The temperature range in which this sinusoidal relation is kept is as wide as 4 to 6 K a

ISSN:8756-663X    

DOI:10.1002/ecjb.4420680505

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

年代:1985

数据来源: WILEY

摘要:

AbstractGe was deposited on n‐type (100) Si substrates by electron beam evaporation and it became clear that to obtain good morphology of a single‐crystal Ge layer, the conditions of crystal growth should be maintained as follows: pressure should be less than 10‐6Pa, the temperature range should be 400‐500°C, and the growth rate should be kept less than 7 Å/s. Moreover, in the growth of GaAs, it was found that we can obtain an epitaxial layer of monocrystalline n‐type GaAs if we use the MOCVD method in which trimethyl gallium (TMG: (CH3)3Ga) and arsine (As H3) are used, silane (SiH4) is used an an n‐type doping gas, the temperature range is 590 to 670°C, the mole ratio of As H3/TMG is 10 to 24, the mole ratio of Si H4/TMG is 2‐5 × 10‐3, and the growth rate is kept below 0.4 μm/min. Zn diffusion is done on n‐type*p‐n junctions, and the resulting light‐emitting diode was observed to have electroluminescence at the peak wavelength of 897 nm at room temperature. In the case of GaAs/Ge/Si structure, the thermal expansion coefficients of Si and GaAs are different and tension is produced so the spectrum shifts to the longer wavelength. Moreover, if the thickness of the GaAs layer becomes less than 5 μ

ISSN:8756-663X    

DOI:10.1002/ecjb.4420680506

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

年代:1985

数据来源: WILEY

摘要:

AbstractDiffused optical waveguides are of considerable interest for the construction of optical integrated circuits. Generally, it is difficult to analyze inhomogeneous waveguides, such as diffused waveguides, because their refractive indices change continuously. Further, it is complicated and difficult to analyze anisotropic inhomogeneous lossy optical waveguides. This paper describes the finite‐element method for the analysis of planar anisotropic inhomogeneous lossy optical waveguides. The validity of the method is confirmed by comparing numerical results of planar isotropic inhomogeneous optical waveguides with exact results. The numerical results of metal‐clad planar anisotropic inhomogeneous optical waveguides are also presented and the effects of metal claddings on the propagation characteristics for the surface waves and the leaky surface waves are exami

ISSN:8756-663X    

DOI:10.1002/ecjb.4420680507

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe development of the thin‐film waveguide dye lasers has created extensive applications in laser technology and fiber optics. This paper reports the laser properties of two types of thin‐film energy‐transfer dye lasers (thin‐film ETDL). One is the mixture‐type doped with a donor‐acceptor dye pair in the polymer thin‐film waveguide, which operates largely by nonradiative resonance transfer; the other is two‐layer type with the active core (layer of acceptor dye) and clad (layer of donor dye), which operates only by radiative transfer. These ETDLs are pumped by an N2laser and operate efficiently as practical compact laser sources in the spectral region of near ultraviolet to violet. Furthermore, the measurement of the energy transfer rate constants in these ETDLs is

ISSN:8756-663X    

DOI:10.1002/ecjb.4420680508

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

年代:1985

数据来源: WILEY

摘要:

AbstractFinding the distributed index formation in the fabrication of planar microlens is important in realizing the optimization of the conditions controlling the distribution as it determines the optical properties. The system is modeled under the assumption that the penetration of the metal dopant ions follows the drift‐diffusion equation. Before this equation is solved, the diffusion constant and the mobility of metal ions in a glass substrate are measured. It is found that the diffusion constant is strongly dependent on the ion concentration. Based on these findings, the drift‐diffusion equation is analyzed numerically to find the concentration distribution in the planar microlens. It is found that the thermal diffusion with a strong concentration dependence contributes significantly to the formation of concentration profile without a t

ISSN:8756-663X    

DOI:10.1002/ecjb.4420680509

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe push‐pull current‐fed dc‐dc converter has been considered as one of the circuit configurations for the dc‐dc converter. According to past studies, this converter is useful from the viewpoint of the voltage stability compared to traditional circuits. This paper considers the fact that the capacitance of the smoothing condenser can be reduced by raising the switching frequency. The relation is determined between the voltage stability and the capacitance of the smoothing condenser by analysis, considering the phase‐delay element in the feedback circuit and the equivalent series resistance of the smoothing condenser. Hence, the push‐pull current‐fed dc‐dc converter is shown to have better voltage stability than the traditional buck‐type converter, even if the capacitance of the smoothing condenser is reduced, while the output voltage ripple increases with the increase of the output current, thereby limiting pract

ISSN:8756-663X    

DOI:10.1002/ecjb.4420680510

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

年代:1985

数据来源: WILEY