摘要:

The performance characteristics of a large‐volume CO2electric‐discharge convection laser operating in a closed‐cycle mode are described. The use of a combined dc and rf excitation field and aerodynamic stabilization techniques resulted in the attainment of a stable and homogeneous discharge. Operating in a master oscillator‐power amplifier mode, continuous‐output power levels greater than 20 kW have been achieved for extended periods of time, with a maximum optical power of 27.2 kW at an efficiency of 17.2%.

ISSN:0003-6951    

DOI:10.1063/1.1654226

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

An InSb spin‐flip Raman laser pumped continously by a carbon monoxide laser near 5.2 &mgr;m has produced Stokes pulses of≲ 10−9‐secduration when an electric field of a few V/cm was applied or removed from the sample. This effect is interpreted in terms of a transient Raman gain, which occurs when electrons are heated or allowed to cool in the conduction band.

ISSN:0003-6951    

DOI:10.1063/1.1654227

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

High‐temperature gettering of Fe, Co, Ni, Cu, and Au by ion‐damaged surface layers on silicon wafers has been studied by Rutherford backscattering of4He+ions incident at 1.75 or 2 MeV. Analysis showed impurity levels in the damaged layers ranging from 1013–1017/cm2. The metals fall into two groups: those which are gettered slowly‐Fe, Co, and Au— and those gettered rapidly‐Cu and Ni. This trend is predicted by a simple diffusion model using published interstitial solubilities and diffusivities.

ISSN:0003-6951    

DOI:10.1063/1.1654228

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The morphological difference between entrance and exit surface damage is examined in terms of Fresnel reflections at the interface of the dielectric and the plasma associated with damage. It is suggested that the standing wave formed at the exit surface by the incident wave and the wave reflected from the plasma‐dielectric interface is responsible for the characteristic pits of exit surface damage, while entrance damage characteristics are due to thermal shock from the hot plasma contiguous to the surface.

ISSN:0003-6951    

DOI:10.1063/1.1654229

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Elastic and piezoelectric constants of CuCl, CuBr, and CuI have been measured. The elastic constants of zinc‐blende‐structure materials when plotted on a reduced scale indicate a striking instability as the Phillips critical ionicity (0. 785) is approached. CuCl is the most piezoelectric of these materials with a piezoelectric constante14=0.41 C/m2at 80°K.

ISSN:0003-6951    

DOI:10.1063/1.1654230

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

A large‐area—cold‐cathode (10 × 100 cm) electron gun has been constructed and used to control of CO2laser amplifier. Energy deposition of 226 J/liter in a time of 1 &mgr;sec has led to a gain of 4.9% cm in an atmospheric‐pressure CO2laser mixture.

ISSN:0003-6951    

DOI:10.1063/1.1654231

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Distributed feedback of a thin‐film optical guided mode has been produced by a periodic perturbation of the guide height. Using photoresist and ion‐milling techniques, gratings with a period of ∼0.2 &mgr; and a peak‐to‐peak height of ∼0.1 &mgr; have been formed on fused silica substrates. A film of polyurethane doped with Rhodamine 6G pumped by an N2laser formed the gain medium. Data presented on the oscillation threshold of several lasers are in agreement with calculated feedback parameters. This technique is capable of producing high‐resolution gratings in durable materials which can provide feedback in low‐gain laser media.

ISSN:0003-6951    

DOI:10.1063/1.1654232

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

An electrostatic copying process based on the pyroelectric effect is described. The effect is demonstrated with single crystals of LiTaO3, ceramic plates of lanthanum‐modified lead zirconate‐titanate (PLZT), and polymer films of polyvinylidene fluoride (PVF2). By employing thin films (0.8 mil) of PVF2to minimize thermal diffusion, we have obtained sufficient resolution to allow charge distributions (images) to be visually observed by dusting the films with conventional electrostatically charged inks. Since the pyroelectric effect is not wavelength dependent, certain advantages over photoconductive techniques, with their inherent wavelength dependence, are possible.

ISSN:0003-6951    

DOI:10.1063/1.1654233

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Images of Fresnel fringes have been obtained in the conventional surface scanning electron microscope operating in the transmission mode. These fringes provide a means for critically evaluating instrument resolution, final lens astigmatism, and source brightness.

ISSN:0003-6951    

DOI:10.1063/1.1654234

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

OxygenK&agr;x rays excited by the impact of 120‐keV protons have been used to determine absolute oxygen surface coverages ranging from 4.8×1014to 5.2×1015atoms/cm2on polycrystalline iron samples mounted in an Auger spectroscopy system. Amplitudes of the electron‐beam‐excited oxygenKL2L2Auger electron spectra obtained from the samples corresponded linearly with the coverages determined by the proton‐excited x rays (PEX). Estimates of the oxygen adatom coverages using the Auger results and the theoretical approach of Bishop and Riviere were found to agree within a factor of 2.15 (± 0.22) with the PEX‐determined coverages.

ISSN:0003-6951    

DOI:10.1063/1.1654235

出版商:AIP    

年代:1972

数据来源: AIP