摘要:

It is shown that inn‐InSb at 77 K, mode I of acousto‐electric excitation exists in transverse magnetic fields above 2 kG, for whichqR≪ 1 (qis the acoustical wave number, andRis the Larmor radius) if the drift motion restores a mean free pathlto giveql> 1. Threshold curves for mode I are calculated. Allowing for the magnetic field dependence of mobility, the applicability of quantum‐mechanical and hydrodynamical theory in different field regions is discussed.

ISSN:0003-6951    

DOI:10.1063/1.1654042

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

A successful new technique for the fabrication of bulk indium tunnel junctions, In (bulk) ‐ Al2O3&sngbnd;Pb, has been developed and was used to determine the value of the reduced energy gap as 2&Dgr;(0) /kTc= 3.58 for bulk polycrystalline indium.

ISSN:0003-6951    

DOI:10.1063/1.1654043

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

An electron‐beam‐controlled discharge has been used to pump a variety of CO2laser gas mixtures at atmospheric pressure in substantial volumes. Electrical and laser properties of the pumped medium have been measured. Small‐signal‐gain coefficients up to 0.045 cm−1were achieved at field strengths of 3 kV/cm.

ISSN:0003-6951    

DOI:10.1063/1.1654044

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

A study is made of Gunn‐diode behavior for various lengths and doping densities. Emphasis is placed mainly on very short over‐critically doped diodes. Such diodes, when biased above threshold, are stable with a high‐field anode layer. The transition to this stable state occurs with or without the intermediary formation of Gunn domains. The relations between the various types of diode behavior and the nature of the small‐signal instability, convective or absolute, in the material is examined.

ISSN:0003-6951    

DOI:10.1063/1.1654045

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Stimulated Raman emission in the visible has been observed in glass‐fiber optical waveguides. Even though the Raman cross section is quite small, relatively low threshold for Raman emission can be achieved because high optical power densities are maintained over long lengths of waveguide. The broad stimulated gain bandwidths available in glass should permit the construction of wide‐band fiber amplifiers and Raman oscillators tunable over a range of 100 Å.

ISSN:0003-6951    

DOI:10.1063/1.1654046

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

A pulsed chemical laser using the reaction between fluorine and hydrogen or deuterium is described. The reactants are mixed at a pressure which is above the second explosion limit, and reaction is initiated by photolytic dissociation of the fluorine. Laser pulse energies of 96 mJ were achieved from hydrogen fluoride, and 350 mJ from carbon dioxide which acquires vibrational energy by transfer from deuterium fluoride. These pulse energies are lower than expected theoretically.

ISSN:0003-6951    

DOI:10.1063/1.1654047

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The results of two experiments utilizing crystalline quartz as the substrate of a thin‐film optical waveguide are presented. TE &rlhar2; TM mode conversion is demonstrated and shown to be due to the anisotropic nature of quartz. Using experimentally measured parameters in the previously reported analysis, we find good agreement between the theory and experiment.

ISSN:0003-6951    

DOI:10.1063/1.1654048

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Cyclotron‐resonance lines inn‐type GaAs at 4.2°K are observed to be anomalously narrow when measured at &lgr; = 220 &mgr;m. Analysis of the resonance line yields an effective mass ratio of 0.068m0and an electron‐impurity scattering time of 3.9×10−12sec compared to a dc scattering time of 4×10−15sec.

ISSN:0003-6951    

DOI:10.1063/1.1654049

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

GaN and InN thin films were grown on sapphire, silicon, and metallic substrates using rf sputtering at temperatures of 25–750°C and presputtering vacuum of 10−8Torr. The GaN films were high in resistivity (> 108&OHgr; cm), but the InN layers were highly conducting with an electron concentration of 7×1018cm−3. The refractive index for GaN ranged from 2.1 to 2.4 at long wavelengths and was dispersive below 8000 Å; the index for InN is higher, 2.9. The absorption coefficient was measured from wavelengths of 2 &mgr; to 2000 Å.

ISSN:0003-6951    

DOI:10.1063/1.1654051

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Ion‐implanted amorphous regions of Si in the presence of Al films 300–700 Å thick are found to recrystallize between 325 and 350°C. This recrystallization occurs at a temperature significantly below both the epitaxial regrowth of the amorphous Si (∼ 600°C) and the Al&sngbnd;Si eutectic of 577°C. In the case of the 300‐Å metallizations, the enhanced low‐temperature reordering of the damaged layer is simultaneously accompanied by an interfacial migration which results in Si transport to the surface of the sample. The observed phenomena are analyzed as a function of anneal temperature by 280‐keV &agr;‐particle backscattering and 1.8–6.2‐eV optical reflectance measurements.

ISSN:0003-6951    

DOI:10.1063/1.1654052

出版商:AIP    

年代:1972

数据来源: AIP