摘要:

Brillouin scattering from thermal longitudinal phonons in Ti in‐diffused LiNbO3waveguides is shown to provide a direct measurement of the optical‐field profiles and the velocity of sound in the in‐diffused region.

ISSN:0003-6951    

DOI:10.1063/1.90208

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The axial drift of a relativistic electron beam along a uniform magnetic field is shown theoretically to lead to significant frequency up‐shifts for linear cyclotron‐wave instabilities driven by velocity‐space anisotropy. This mechanism suggests novel means for the development of devices for generation of intense far‐infrared power.

ISSN:0003-6951    

DOI:10.1063/1.90209

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The electron penetration through thin films of PMMA has been simulated using two different Monte Carlo approaches. One approach is conventional, in that the energy loss of the electron along its trajectory is computed using the continuous‐slowing‐down approximation. The statistical nature of inelastic scattering events, as well as the elastic scattering events, is taken into account in the second approach, which is based on an extension of Gryzinski’s semiempirical expression for the excitation of core electrons and also the excitation of valence electrons through the use of an appropriate mean binding energy. The energy distribution of transmitted electrons through PMMA films of various thicknesses obtained by both methods are compared. The second approach is shown to give a more realistic answer for the transmitted electron energy distribution.

ISSN:0003-6951    

DOI:10.1063/1.90210

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Direct pulsed‐laser photoionization of neutral atomic hydrogen or deuterium in a discharge plasma is shown to result in large voltage changes across the electrodes. The ground‐ and excited‐state densities and the translational temperature of the H and D atoms within the plasma are probed by this technique.

ISSN:0003-6951    

DOI:10.1063/1.90211

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

We report In1−xGaxAsyP1−y/InP photodiode detectors with external quantum efficiencies of 50–70% without antireflection coating. The short‐ and long‐wavelength response limits of these very efficient detectors can be compositionally tuned to lie anywhere in the wavelength range 0.9<&lgr;<1.7 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.90212

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A simple method for realizing the desired light coupling for an optical directional coupler is presented. This method consists of loading a metal film on one of the waveguides in the undesired coupling region. The effective coupling length, fabricated inc‐plate LiNbO3, could be changed from 0 to 3L0(L0: 0‐dB coupling length) by controlling the length of the metal film.

ISSN:0003-6951    

DOI:10.1063/1.90213

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Light emission via inelastic tunneling (LEIT) has been observed from the metal‐insulator‐semiconductor tunnel‐junction Al‐Al2O3‐ Sn‐doped indium oxide (ITO). The spectra exhibit the bias‐voltage‐dependent upper‐frequency quantum cutoff relation. These devices were stable at room temperature for months at a time while biased to 3 V. The external quantum efficiency of this metal‐insulator‐semiconductor system is about 0.1 that of the metal‐insulator‐metal system Al‐Al2O3‐Ag. Enhancement of the light emission using silver particle resonators is also reported.

ISSN:0003-6951    

DOI:10.1063/1.90214

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

We have measured Schottky‐barrier electroreflectance spectra of an In0.79Ga0.21As0.54P0.46LPE layer at 81 K. Analysis of the spectra has enabled us to determine the interband reduced mass of the quaternary alloy together with the values of the band gap and spin‐orbit splitting. The obtained reduced mass &mgr;=0.033m0, in agreement with the value calculated from interpolations of the accepted values for the related binary compounds.

ISSN:0003-6951    

DOI:10.1063/1.90215

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The characteristic delay, rise, and decay times of recombination radiation at high exciton densities (P∞‐band) in CdSe monocrystal (77 K) were measured with 2‐psec time resolution and found to be 34±6, 9±2, and 16±3 psec, respectively. The values of the rate constants of the exciton‐exciton interaction and of the binding of free carriers into excitons were estimated.

ISSN:0003-6951    

DOI:10.1063/1.90192

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The focusing and phase conjugation of photon echoes was observed in Na vapor. If the radius of curvature of the first pulse wasR1and the second pulseR2, the radius of curvature of the echo was given by 1/RE=2/R2−1/R1and the echo center of curvature or focus followed from the phase &fgr;E(r) =2&fgr;2(r)−&fgr;1(r) in the Na cell.

ISSN:0003-6951    

DOI:10.1063/1.90193

出版商:AIP    

年代:1978

数据来源: AIP