摘要:

The results of HgBr laser injection locking experiments are presented. The output energy and spectrum of an injection locked HgBr laser has been measured versus injection wavelength. When injection locking near 502 nm, the narrow band (0.05‐nm FWHM) output energy was 30% higher than the broadband HgBr laser output. The wall plug efficiency of the injection locked HgBr laser is 1.3%.

ISSN:0003-6951    

DOI:10.1063/1.92582

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

It is shown that by modifying the layer structures of the conventional multiquantum well (MQW) lasers, extremely lowJthof 250 A/cm2(averaged value) for broad‐area Fabry–Perot diodes of 200×380 &mgr;m was obtained. This was achieved as a result of utilizing the beneficial effects of the two‐dimensional nature of the confined carriers, the improved injection efficiency of the carriers into the GaAs wells, and an increased optical confinement factor in these modified MQW lasers. It was also determined that for low threshold operation the optimal AlAs compositionxin the AlxGA1−xAs barrier layers is about 0.19 when GaAs wells are used and for barrier and well thicknesses ≳30 and 100 A˚, respectively.

ISSN:0003-6951    

DOI:10.1063/1.92583

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Integrated optics techniques have been used to form a three‐mirror laser diode configured to form a long active cavity and a short passive cavity. The third mirror results from an abrupt etched step down to the waveguide layer of a large optical cavity heterostructure laser. We have observed predominantly single‐frequency operation at current levels up to 1.5 times threshold. For certain ratios of passive‐to‐active cavity length, these devices operated multimode within a narrow frequency range, whereas diodes with different length ratios emit two modes widely separated in frequency.

ISSN:0003-6951    

DOI:10.1063/1.92584

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Cadmium‐doped InGaAsP/InP double heterostructure lasers (&lgr;∼1.3 &mgr;m) have been made for the first time with threshold current densities as low as 1 kA/cm2. The low diffusion rate and distribution coefficient of cadmium facilitate locating thep‐njunction reproducibly at the active region. High yield from a given wafer and a very uniform performance in a wide range of dopant concentrations are observed. The high vapor pressure of the Cd which has deterred previous investigations of this dopant does not seem to be a problem under the conditions used.

ISSN:0003-6951    

DOI:10.1063/1.92585

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Time‐delayed correlation measurements with a CO2laser, multichord plasma interferometer show density perturbations propagating along the local magnetic field in the edge region of the ZT‐40M reversed field pinch. The observed speed is consistent with ion‐acoustic propagation. Such measurements of field‐parallel waves with long wavelength (&lgr;∥≳several centimeters) may provide a quasilocal, quasi‐cw diagnostic of the sound speed in many low &bgr; magnetically confined plasmas, useful in estimating plasma temperatures.

ISSN:0003-6951    

DOI:10.1063/1.92586

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

In this letter we report a combination of surface chemical and voltammetric treatments that optimize the stability and performance ofp‐Si/V2+−V3+, 4MHCl/C solar cells. The power conversion efficiency is 6.1% under 60‐mW/cm2illumination. The results of capacitance‐voltage measurements and the improved solar cell properties are discussed on the basis of an electrolyte‐oxide‐semiconductor energy band diagram.

ISSN:0003-6951    

DOI:10.1063/1.92587

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The unity sticking coefficient of Si and the good electrical and optical properties of Si‐doped films make Si a near ideal dopant for GaAs grown by molecular beam epitaxy (MBE). However, the incorporation mechanism of Si at high doping levels differs from that at moderate levels. We found that the maximum doping concentration that can be obtained with Si is 6×1018cm−3. Above this doping concentration Si precipitates, causing a decrease in the free‐carrier concentration and the mobility. A detailed discussion of the incorporation mechanism at high doping, and the effects of the substrate temperature and As4/Ga ratio on Si incorporation at moderate doping is presented.

ISSN:0003-6951    

DOI:10.1063/1.92562

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Thin‐film homojunction gallium arsenide solar cells ofp+/n/n+configuration have been deposited on tungsten coated graphic substrates by the reaction of gallium, hydrogen chloride, and arsine containing appropriate dopants. Solar cells of 8‐cm2area with an AM1 efficiency of about 7% have been prepared for the first time. The solar cells are characterized by dark and illuminated current‐voltage and quantum efficiency measurements.

ISSN:0003-6951    

DOI:10.1063/1.92563

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Laser‐excited photoluminescence emission has been measured from 2.5 to 100 °K for single crystals of Zn3P2grown either by sublimation or by iodine chemical transport. Sublimation‐grown crystals show two main peaks at 1.361 and 1.354 eV at 2.5 °K, each of which has a phonon replica displaced by 43 meV, and a third much smaller peak observable only above 20 °K at 1.367 eV. Iodine‐transport grown crystals show a broad peak at 2.5 °K at 1.320 eV and its phonon replica displaced by 42 meV. The photon energy for peak emission shifts with excitation intensity as is typical of pair transitions, for the major bands seen at 2.5 °K. Temperature dependence measurements identify the donor and acceptor ionization energies corresponding to each of these bands.

ISSN:0003-6951    

DOI:10.1063/1.92564

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The effect of varying compositional gradient on the propagation of misfit dislocations in the step‐graded molecular‐beam epitaxy growth of InGaAs is studied by cross‐sectional transmission electron microscopy. For a composition change of 15% across the interface, the misfit dislocations are almost all confined to the interface and few defects are observed in the InGaAs layer grown. The confinement of misfit dislocations at the interfaces becomes less effective for the 5% cases; a new phenomenon of stress relieving is observed where a high‐density center of inclined dislocations is formed which leaves a large neighboring area with very low density of defects.

ISSN:0003-6951    

DOI:10.1063/1.92565

出版商:AIP    

年代:1981

数据来源: AIP