摘要:

The use of parametrically mixed acoustic surface waves to remotely scan and process the contents of zinc−oxide−on−silicon charge storage cells is demonstrated. The write, erase, and store characteristics of the memory cells are investigated. The signal−processing capability of the device is illustrated by the correlation of a line of stored information with a biphase coded input signal.

ISSN:0003-6951    

DOI:10.1063/1.88119

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

An acousto−optic guided−light−beam device utilizing two surface acoustic wave interdigital transducers, which are staggered in their center frequency and tilted in their propagation direction, on an essentially single−mode optical guiding layer of aY−cut LiNbO3substrate has been shown to be capable of providing a very wide bandwidth. Deatiled measurements on the diffraction efficiency and the deflection angle of the light beam versus the frequency of the driving signal, usign a 6328−A˚ He−Ne laser light, are presented. The measured −3 dB bandwidth of the device is close to 200 MHz, which is more than an order of magnitude larger than that obtained in previous devices, with the measured electric driving power of 200 mW at 50% diffraction efficiency. The new device configuration introduced here should be very useful for wide−band applications such as a guided−wave acousto−optic rf spectrum analyzer and high−speed multiport switches for fiber/integrated optics.

ISSN:0003-6951    

DOI:10.1063/1.88120

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A monolithic zinc−oxide−on−silicon surface wave convolver has been used to image optical patterns and store them for long periods of time. A light pattern is stored by projecting it onto a semitransparent top convolver electrode which has an applied negative dc bias. Slow states associated with the zinc oxide are charged in the regions exposed to the light. This charge pattern, as observed using surface wave convolution, persists even when the light is removed. Retention of the pattern for several days has been demonstrated with this device.

ISSN:0003-6951    

DOI:10.1063/1.88097

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

In relativistic diodes, ions are emitted from the anode plasma surface. The space charge of these ions enhances the electron emission. One−dimensional analysis and two−dimensional computer simulation are used to show the necessity of including this effect in any realistic diode theory.

ISSN:0003-6951    

DOI:10.1063/1.88121

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

The surface peak of the channeling energy spectrum has been investigated as a function of energy of the incident beam. An increase of the surface peak value with energy has been observed for axial channeling in silicon ⟨110⟩, germanium ⟨111⟩, molybdenum ⟨111⟩, and vanadium ⟨100⟩ and ⟨110⟩ crystals with low surface contamination. The influence of oxide layers on the energy dependence effect has been investigated on silicon crystals.

ISSN:0003-6951    

DOI:10.1063/1.88098

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Intrinsic damage of NaCl upon exposure to intense laser pulses is discussed in terms of electron kinetic processes. Avalanche ionization is confirmed to be the dominant mechanism at the ruby frequency. However, compared to pure avalanche breakdown, both five−photon absorption and, to a lesser extent, the presence ofFcenters reduce the damage threshold by providing a large concentration of free carriers at the onset of avalanche ionization. Three−photon absorption contributes extensively to damage at the doubled ruby frequency. The dependence of the damage threshold on the laser pulse length is calculated and it is shown that its measurement can provide information on the role of multiphoton absorption in the damage process. At a given wavelength multiphoton contributions become increasingly more important as the laser pulse length decreases.

ISSN:0003-6951    

DOI:10.1063/1.88122

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

The channeling effect technique has been used to investigate the annealing of the ’’amorphous’’ layer produced in Si by 40−keV Pb implants with fluences ranging between 5×1013and 5×1015ions/cm2. The amount of residual disorder, after an anneal of 30 min at 650 °C, shows a dose dependence and increases strongly with Pb fluence, thus indicating the influence of the dissolved lead atoms in the recrystallization process.

ISSN:0003-6951    

DOI:10.1063/1.88123

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

The recent observations by Loy of amplitude modulation and compression of infrared laser pulses caused by passage through the dispersive modulator (a cell containing dilute NH3vapor with a Stark−modulated resonant frequency) are explained. It is shown that there is a formal equivalence between (i) the passage of a near−resonant light beam through a vapor with a time−dependent resonant frequency, and (ii) the passage of a frequency−modulated light beam through a vapor with a constant resonant frequency. For low−intensity light this equivalence reduces the problem to the optical analog of chirp radar.

ISSN:0003-6951    

DOI:10.1063/1.88124

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Small−bore capillary tubes exhibit very high optical gains and saturation intensities in flowing gas CO2systems. However, these parameters may vary greatly in the axial direction due to the nonuniform axial pressure distribution. Use of porous−wall BeO capillary tubes makes it possible to attain a more uniform pressure distribution and to usefully scale capillary waveguide amplifiers to longer lengths.

ISSN:0003-6951    

DOI:10.1063/1.88125

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Thermoelectric power and electrical resistivity of thin (<1000 A˚) copper films annealed at different temperatures have been studied. The data have been utilized to obtain the contribution to thermoelectric power by the structural defects in the films. This contribution is comparable in magnitude to the bulk value. It increases with film thickness giving rise to a strong thickness dependence of thermoelectric power at thicknesses considerably larger than the mean free path of the conduction electrons.

ISSN:0003-6951    

DOI:10.1063/1.88099

出版商:AIP    

年代:1975

数据来源: AIP