摘要:

A subpicosecond laser has been used to trigger a GaAs photoconductive switch driving a dipole antenna. The microwave transient produced was measured with a correlation technique to have a FWHM of less than 3 psec. This technique was also used in a contactless measurement of the 250‐psec lifetime of a GaAs sample.

ISSN:0003-6951    

DOI:10.1063/1.92719

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Homogeneous and stable avalanche/self‐sustained discharges of 200‐nsec duration have been obtained in typical XeCl laser gas mixtures at relatively high gas pressures (1–4 atm) and high energy loadings (100–400 J/liter‐atm). The laser output waveform, however, is found to be surprisingly sensitive to changes in gas pressure and composition. Under certain conditions, the laser power remains nearly constant for 200 nsec, so that the total output energy scales roughly with the discharge duration. The highest XeCl laser pulse energy extracted from a 1‐liter volume in this series of experiments is 3.2 J at ∼4% intrinsic efficiency.

ISSN:0003-6951    

DOI:10.1063/1.92720

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A thin‐film optical waveguiding evanescent dye laser was realized by an activated square‐shape Rh6 G top layer on a thin‐film glass waveguide. When a N2UV laser was focused on a diagonal line of the square dye film by a cylindrical lens, a pair of corners played a role as a corner reflecting resonator. A distinct resonance and transverse modes were observed.

ISSN:0003-6951    

DOI:10.1063/1.92721

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We have used an in‐cavity hot CO2cell to convert a conventional transversely excited atmospheric (TEA) CO2laser to operation on the 00 °2 sequence transitions. Careful cavity design enables us to attain efficient energy extraction. Output energies of 6 J per pulse have been obtained from a nonselective cavity, while a grating‐tuned cavity produces numerous sequence lines having output energies in excess of 2 J per pulse.

ISSN:0003-6951    

DOI:10.1063/1.92722

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We propose a novel mechanically scannedB‐scan system for imaging the interior of solids with diffraction‐limited resolution. By utilizing an additional spherical surface in conjunction with a conventional acoustic lens, it is possible to reduce spherical aberration, (which would otherwise seriously degrade the imaging performance), to a negligible value. In typical situations, it is possible to scan the focus through a depth of several hundred wavelengths.

ISSN:0003-6951    

DOI:10.1063/1.92723

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Continuous single‐crystal Si films on SiO2have been prepared by a simplified version of the technique for lateral epitaxy by seeded solidification (LESS). The new method employs transient heating by a simple stationary graphite heater, while the original method utilized two graphite heaters, one of which was moved during LESS processing. The Si films obtained by the one‐heater method are comparable in crystal quality to those prepared by the two‐heater method.

ISSN:0003-6951    

DOI:10.1063/1.92724

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A molecular dynamics simulation has been used to study the times at which atoms are ejected during sputtering events. Plots of the atom ejection time versus distance from the impact point indicate that many sputtering events occur along a roughly circular front that propagates outward at hypersonic speed.

ISSN:0003-6951    

DOI:10.1063/1.92725

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

This letter provides the first experimental evidence that substrate heatingduringpulsed‐laser annealing (PLA) of ion‐implanted silicon can significantly improve the electrical properties of the laser recrystalized region due to the reduction of the regrowth velocity. It is also shown that by using the optimum PLA condition, the open‐circuit voltageVOCand the fill factor of ion‐implanted, laser‐annealed solar cells are improved by increasing the emitter dopant concentrations, whereas the short‐circuit currentJSCremains fairly constant, results which are in qualitative agreement with theoretical predictions.

ISSN:0003-6951    

DOI:10.1063/1.92704

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Chemical etching and cleaning procedures that produce the most abrupt dielectric discontinuities between bulk and ambient (cleanest and/or smoothest surfaces) are determined by ellipsometry for single crystals of Si, Ge, and some III‐V compounds. Differences among high‐symmetry orientations for Si and Ge indicate that preferential etching may be a factor in minimizing the amount of interface material left at a surface.

ISSN:0003-6951    

DOI:10.1063/1.92705

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The electron attachment rate constant of HCl is measured ine‐beam‐excited mixtures of N2/HCl and Ar/H2/HCl, by observing the electron current decay after termination of ane‐beam pulse. The possible enhancement of attachment due to vibrational excitation of HCl undere‐beam pumping is studied, by performing measurements withe‐beam currents differing by a factor of 30. The consequences of the results for XeCl laser kinetics are discussed.

ISSN:0003-6951    

DOI:10.1063/1.92706

出版商:AIP    

年代:1981

数据来源: AIP