摘要:

Experimental data fromz‐cut LiNbO3Mach–Zehnder interferometers show that electrical contact to the device electrodes leads to the large thermal instability of the intrinsic phase bias. Withdrawing contact from the electrodes causes the thermal instability to virtually disappear. A model is proposed in which contact to the electrodes creates strong gradients in the local surface potential near the electrodes when unscreened pyroelectrically induced surface charges are present, independent of whether the probes are floating or grounded. The resulting differential electric field strength in the interferometer branches gives rise to the observed thermal instability, which is five orders of magnitude larger than the calculated instability due to the pyroelectric effect alone. The model of the instability mechanism is used to suggest methods of reducing the instability.

ISSN:0003-6951    

DOI:10.1063/1.97419

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We present the first experimental demonstration of spatial instability in the nonlinear evolution of the state of polarization of an intense light beam in a birefringent Kerr‐like medium. As the peak power crosses the threshold for the instability, we observed strong intensity‐dependent power transfer between the two counter‐rotating circularly polarized waves propagating along a birefringent optical fiber. The experimental results agree well with the theory.

ISSN:0003-6951    

DOI:10.1063/1.97420

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The fabrication and performance characteristics of single frequency integrated external cavity lasers of the coupled cavity type and the distributed Bragg reflector type are described. The active cavity section of these devices utilizes the double channel planar buried heterostructure scheme for current confinement. The lasers emit near 1.55 &mgr;m. The threshold current of these lasers is in the range 70–120 mA. cw linewidth of 7 MHz has been obtained for a 2‐mm‐long laser at an output power of 3 mW. We believe lasers with longer external cavity should exhibit lower cw linewidths.

ISSN:0003-6951    

DOI:10.1063/1.97421

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

HD formation reaction was investigated in H2plasma over deuterium‐incorporating hydrogenated amorphous silicon (a‐Si:H:D). The activation energy of the reaction was determined to be 2.4±0.7 kcal mol−1, which was consistent with the abstraction reaction of hydrogen from some silane derivatives by hydrogen atoms. The HD formation reaction could be explained by the hydrogen abstraction reaction. The hydrogen abstraction froma‐Si:H surface by H atoms is thought to be one of the elementary growing processes of ana‐Si:H in a SiH4‐H2plasma.

ISSN:0003-6951    

DOI:10.1063/1.97422

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The diffusion of metals through a less‐electronegative metal layer is studied for its dependence on ambient gases. When the diffusion is essentially one directional with little interdiffusion, the observed ambient dependence is in agreement with that described by the surface potential model proposed earlier. An enhanced diffusion is expected when the ambient increases the work function of the less‐electronegative metal through which the diffusion of the more‐electronegative one is studied. This has been observed for the diffusion of Au and Cu across the intermediate Ni layer in the Au/Ni/Cu structure under both oxygen and hydrogen, and for the outdiffusion of Cu through Ni in the Ni/Cu structure by oxygen.

ISSN:0003-6951    

DOI:10.1063/1.97423

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

30–90 nm Ti films sputter deposited onto 50 nm Si3N4have been rapid thermal annealed for 30 s in Ar and N2ambients, and the phases formed identified using Auger electron spectroscopy, transmission electron microscopy, and electron diffraction. Reaction at 900 °C produces TiN surface and interfacial layers and an intermediate TiSi2layer. The Ti‐Si‐N ternary phase diagram is used to explain the reaction sequence.

ISSN:0003-6951    

DOI:10.1063/1.97424

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Characterization results are given for a set of TiNxfilms grown on sapphire substrates at temperatures between 140 and 850 °C. A relationship between resistivity and spectral reflectivity is established, with highest reflectivities and lowest resistivities observed for the highest substrate temperatures. It is found that grain orientation within the films is random except at the highest deposition temperature where a preferred 100 orientation is indicated. Measurement of the superconducting transition temperature, lattice parameter, and microcrystalline texture of each film has been made and correlated with the stoichiometry, electrical, and optical properties.

ISSN:0003-6951    

DOI:10.1063/1.97425

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Transmission electron microscopy of the compounds formed from the reaction between amorphous Si and thin (0.5–20 nm) layers of Pd and Pt reveals the early formation of crystalline silicides. The presence of phase in an amorphous state prior to crystallization is not observed. These results appear to be in agreement with earlier results of surface electron spectroscopy studies on these systems.

ISSN:0003-6951    

DOI:10.1063/1.97426

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Low‐temperature excitation and photoluminescence spectra are described for single GaAs/Al0.37Ga0.63As quantum wells grown by molecular beam epitaxy with and without a 2‐min interruption of growth at the heterointerfaces. The spectra from samples grown with interruption include well‐resolved multiple sharp peaks which are due to changes in well thickness of one monolayer and to bound excitons. These peaks are as narrow as 1.0, 1.7, and 6.0 meV for single wells of width 57, 28, and 17 A˚, respectively.

ISSN:0003-6951    

DOI:10.1063/1.97427

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We investigated the current‐voltage characteristics of the double barrier, resonant tunneling structure, using a self‐consistent method. We note the significance of the effects of band bending and buildup of space charge in the quantum well. For the peak current, our calculated results agree with the measured results very well. However, the measured valley current is much greater than the calculated values.

ISSN:0003-6951    

DOI:10.1063/1.97428

出版商:AIP    

年代:1986

数据来源: AIP