摘要:

Room‐temperature continuous‐wave oscillation with an emission power in excess of 1 mW was achieved in vertical‐cavity surface‐emitting lasers containing a 0.5‐&mgr;m‐thick GaAs active layer sandwiched between a distributed Bragg reflector (DBR) and a hybrid metal DBR. The devices have a cw threshold current of 40 mA in 15‐&mgr;m‐diam size and aT0of 115 K. Fiber butt coupling and pseudorandom data modulation of these lasers with open eyes up to 500 Mbit/s were demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.102002

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The growth and characterization of strained In0.25Ga0.75As‐GaAs‐Al0.20Ga0.80As quantum well lasers grown by metalorganic chemical vapor deposition using ethyldimethylindium (EDMIn) are described. A vapor pressure of 0.56 Torr at 11 °C has been extracted from the growth rates of thin InGaAs layers by transmission electron microscopy. Data on reproducibility in quantum well size are presented which indicate long‐term stability in the EDMIn vapor pressure. Laser performance in samples grown with EDMIn is equivalent to, and in some cases better than, those grown with trimethylindium.

ISSN:0003-6951    

DOI:10.1063/1.102003

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Enhanced Kerr rotation spectra are measured in thin magnetic layers on silver. Also, variable angle of incidence spectroscopic ellipsometry is employed to measure the optical dielectric function of both the thin magnetic layer and the underlying thick silver layer. These results are explained quantitatively using the electromagnetic theory for reflection of light from multiple layers of isotropic and gyrotropic materials.

ISSN:0003-6951    

DOI:10.1063/1.102004

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The rate constant for electron collision quenching of KrF(B) has been reassessed by analyzing previous theoretical [A. Hazi, T. Rescigno, and A. Orel, Appl. Phys. Lett.35, 477 (1979)] and experimental [D. Trainor and J. Jacob, Appl. Phys. Lett.37, 675 (1980)] data. From this analysis we recommend that the rate constant for electron collision quenching of KrF(B), used for modeling electron beam and discharge excited lasers, should be 3–6×10−8cm3 s−1.

ISSN:0003-6951    

DOI:10.1063/1.102005

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Spatial distribution profiles of leaky surface acoustic wave velocity (VLSAW) and attenuation across the diameters of cladded glass fibers are presented. The profiles are obtained by using a novelV(x,z) analysis with a reflection scanning acoustic microscope operated at 775 MHz, and are compared with optical refractive index profiles. Optical fibers with different dopants and dopant concentrations have been investigated. The role of acoustic property profiles in the design of optical and acoustic fibers is outlined.

ISSN:0003-6951    

DOI:10.1063/1.102006

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

It is shown that the etch rate of photoresist can be greatly enhanced by adding 1% of nitrogen into the oxygen plasma. An increase in the atomic oxygen concentration is shown to be responsible for this enhancement in the etch rate. A further enhancement in the etch rate is obtained by introducing CF4into the O2‐N2plasma. The enhancement in the etch rate of photoresist in the CF4‐N2‐O2mixture is the result of an increase in the atomic concentrations of oxygen and fluorine in the plasma.

ISSN:0003-6951    

DOI:10.1063/1.102007

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We have analyzed the structure of tilted superlattices on atomically stepped surfaces by using atomic force microscopy to detect ridges of GaAs formed by the selective oxidation and removal of intervening AlAs regions. Oxides were removed in a liquid cell of the atomic force microscope while scanning. We have demonstrated plan views which reveal the superlattice length and width uniformity, but the method is also in principle suited for cross‐sectional samples.

ISSN:0003-6951    

DOI:10.1063/1.102008

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Prethinned polycrystalline Ge TEM samples were irradiated with 1.5 MeV Kr+ions at room temperature while structural and morphological changes were observedinsituin the Argonne High Voltage Electron Microscope‐Tandem Facility. After a Kr+dose of 1.2×1014ions/cm2, the irradiated Ge was completely amorphized. A high density of small void‐like cavities was observed after a Kr+dose of 7×1014ions/cm2. With increasing Kr+ion dose, these cavities grew into large holes transforming the irradiated Ge into a sponge‐like porous material after 8.5×1015ions/cm2. The radiation‐induced nucleation of void‐like cavities in amorphous material is astonishing, and the final structure of the irradiated Ge with enormous surface area may have potential applications.

ISSN:0003-6951    

DOI:10.1063/1.102009

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Measurements of the low‐temperature mixing of several 5d–4dbilayers by 600 keV Xe ions have strongly supported the assumption of a thermal spike mechanism. Quite disturbingly, however, the Au‐Ag mixing rate appeared to exceed theoretical predictions by about a factor of 3. A closer examination of this system shows the discrepancy to be caused by the formation of a strongly nonuniform Au surface structure during irradiation. An improved value for the mixing rate is in reasonable agreement with predictions.

ISSN:0003-6951    

DOI:10.1063/1.102010

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The interface structures of SiOx/Si and Si/SiOx/Si (x&bartil;2) formed by molecular beam deposition (MBD) were examined by high‐resolution transmission electron microscopy. The MBD SiO2/Si buffer layer interface was atomically flat in both samples. On the other hand, the Si overlayer/MBD SiO2layer interface had a rough configuration. In the Si/SiO2/Si sample with a 7.5‐A˚‐thick SiO2buried layer, the polycrystalline Si overlayer was separated from the Si buffer layer by the thin SiO2layer. A 2.5 A˚ reduction of the SiO2buried layer thickness to 5.0 A˚ led to the epitaxial growth of the Si overlayer. In this sample, the SiO2layer formed island morphology and epitaxial information was given to the overlayer through the exposed surface of the buffer layer. The epitaxial growth mechanism of the Si overlayer was also discussed.

ISSN:0003-6951    

DOI:10.1063/1.102298

出版商:AIP    

年代:1989

数据来源: AIP