摘要:

Ridge waveguide AlGaAs/GaAs distributed feedback lasers with multiple quantum well structure were fabricated for the first time. The threshold current of 28 mA, which is the lowest ever reported among AlGaAs/GaAs distributed feedback lasers, was obtained at room temperature. Stable single longitudinal and transverse mode oscillation was observed over the wide temperature range. The dynamic linewidth was also measured and it was five to six times smaller than that of a double heterostructure distributed feedback laser.

ISSN:0003-6951    

DOI:10.1063/1.96779

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Design criteria are presented for strong in‐phase coupling of diffraction‐coupled phased‐array diode lasers. Theoretical predictions are confirmed by our experimental observations of double‐lobe and single‐lobe far‐field patterns.

ISSN:0003-6951    

DOI:10.1063/1.96780

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The population of then=2 level of atomic hydrogen and the collisional relaxation rates of then=3 andn=4 levels during the conductive phase in the positive column of a high‐current ( J∼100–400 A/cm2) pulse in a hydrogen thyratron were measured. These results demonstrate laser‐induced fluorescence to be a usefulinsitudiagnostic for high‐current switch plasmas.

ISSN:0003-6951    

DOI:10.1063/1.96781

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The use of attaching gases in an externally sustained diffuse discharge opening switch with a low attachment rate at low values ofE/Nand a high attachment rate at high values ofE/Nallows the discharge to operate with low losses in the closed switch phase and to achieve fast opening after the sustainment source is turned off. Such an attacher generates aJ‐E/Ncharacteristic with a negative differential conductivity in an intermediateE/Nrange. Such a characteristic obstructs the closing process of the discharge if it is operated in a high impedance system. Experiments demonstrating these effects are presented for electron beam sustained discharges in mixtures of argon and C2F6.

ISSN:0003-6951    

DOI:10.1063/1.96782

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The current formulation for atom location by channeling enhanced microanalysis requires three characteristic x‐ray spectra and is overdefined [J. C. H. Spence and J. Tafto, J. Microscopy130, 147 (1983)]. A formulation is presented where only two characteristic x‐ray spectra are needed to determine the distribution of substitutional impurity atoms in a layered compound.

ISSN:0003-6951    

DOI:10.1063/1.96783

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Thin‐film ZnS:Mn electroluminescent devices can exhibit, under pulsed electrical excitation, a double light pulse, as has been previously observed in other phosphors. We specify the conditions under which this phenomenon appears and relate it to the basic mechanism of carrier emission in the active layer.

ISSN:0003-6951    

DOI:10.1063/1.96784

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Chemical etching using a 1:5:40 HF‐HNO3‐CH3COOH solution has been used for the evaluation of hydrogenated amorphous silicon (a‐Si:H) films. The dissolution rate ofa‐Si@B:H films and the structural features brought out by etching have revealed significant differences in the properties ofa‐Si:H films deposited in hydrogen and helium atmospheres. Unintentionally contaminateda‐Si@B:H films have also been found to show considerably higher dissolution rate than intrinsic films, and the dissolution rate measurements may be used to optimize the deposition conditions.

ISSN:0003-6951    

DOI:10.1063/1.96785

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Polycrystalline silicon thin‐film transistors have been fabricated using photochemical doping with phosphorus from the gas phase by ultraviolet laser. The results obtained show the technique to be a viable alternative to ion implantation for applications such as three‐dimensional very large scale integrated circuits.

ISSN:0003-6951    

DOI:10.1063/1.96786

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Crystal growth of GaAs by switched laser metalorganic vapor phase epitaxy (SL MOVPE) is reported. This growth technique is achieved by combining laser MOVPE and atomic layer epitaxy. The growth process in SL MOVPE can be explained by a model which assumes that trimethylgallium adsorbed on the crystal surface is decomposed in a photocatalytic reaction and that the decomposition rate depends on the surface species present on the substrate.

ISSN:0003-6951    

DOI:10.1063/1.96787

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Low resistivity semiconducting films of ZnSe have been deposited at temperatures as low as 120 °C using dc magnetron co‐sputtering of Zn and In (dopant) targets in a reactive atmosphere of H2Se/Ar. Yellowish transparent films of ZnSe on glass and conductive transparent oxide‐coated glass substrates were obtained having a room‐temperature resistivity as low as 20 &OHgr; cm. Atomic absorption analysis showed a Zn to Se ratio of 49.8:49.0 and In concentration of about 1% for the reactively sputter‐deposited ZnSe:In films on glass. Optical absorption/transmission measurements yielded an energy band gap of about 2.65 eV at room temperature. X‐ray diffraction results indicated highly oriented polycrystalline films on glass with thecaxis parallel to the plane of the film.

ISSN:0003-6951    

DOI:10.1063/1.96788

出版商:AIP    

年代:1986

数据来源: AIP