摘要:

A multiple electric discharge using six pairs of electrodes to obtain a uniform volume of ionized gas suitable for the excitation of a cw CO2laser is described. Two methods of connection are investigated; parallel in which the current in adjacent discharges is in the same direction and antiparallel in which current flow in adjacent discharges is opposed. An input power density of the order of 4.18×104W/l/atm was obtained which is of the order of twice that obtainable with a conventional axial discharge system. The results are applicable to axial excitation lasers (parallel) and transverse excitation (antiparallel).

ISSN:0003-6951    

DOI:10.1063/1.93283

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Transparent and heat reflecting indium tin oxide films were prepared by electron beam evaporation of In2O3+9 mol.% SnO2onto glass in an oxygen atmosphere of ∼5×10−4Torr. Visible light absorption less than 2%, thermal infrared reflectance exceeding 90%, and a dc resistivity of ∼3×10−4&OHgr; cm were obtained for 0.3‐&mgr;m‐thick films deposited on a substrate at 300 °C. Similar properties could be achieved with substrate temperatures as low as 150 °C. By antireflection coating the films with an MgF2layer, the visible transmittanceexceededthe transmittance of the uncoated glass while the infrared reflectance was practically unchanged.

ISSN:0003-6951    

DOI:10.1063/1.93103

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The refractive indices of the ferroelectric vinylidene fluoride‐trifluoroethylene copolymer have been investigated. The copolymer reveals birefringence in all its composition ranges. Birefringence of the copolymer film is observed even at higher temperatures than the Curie temperature. The noticeable decrease of the refractive indices at around the Curie temperature is caused by a change of the density.

ISSN:0003-6951    

DOI:10.1063/1.93104

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

A potential new mode of operation of an electron synchrotron radiation device is described, representing a unification of concepts encompassing gyrotron and free‐electron laser devices. The GYROFEL configuration utilizes the predicted axial or longitudinal electron beam bunching to allow enhancement of forward‐directed, Doppler‐shifted synchrotron radiation, provided that appropriate electron beam/wave velocity synchronism occurs. Computer simulations and preliminary experimental data are presented in support of this microwave laser concept.

ISSN:0003-6951    

DOI:10.1063/1.93105

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Experimental results on interactions of a bistable laser with an external optical cavity are presented. Switching of a bistable injection laser can be done by varying the amount of optical feedback. The optical switching is accompanied by a switching of the voltage across the absorber section. This can be utilized in digital optical disk readout. A bistable laser with an antireflection coating on one facet is more suitable for this task. No pulsations can be observed in a bistable laser with optical feedback if the absorber section is biased with a constant current source; but when it is biased with a voltage source, pulsation occurs at the external cavity round trip frequency. This indicates that even though the intrinsic absorption of the semiconductor material does not saturate easier than the gain, the presence of such absorptions in GaAs lasers can still produce pulsations when the electrical aspect is taken into account.

ISSN:0003-6951    

DOI:10.1063/1.93106

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

A new visible laser, the V channeled substrate inner stripe laser, is developed. This laser can internally confine the current into the V‐channel by using a thinn‐GaAs layer grown on thep‐GaAs substrate. cw threshold currents were 35–45 mA in the visible spectral range of 770–790 nm. And highly stable transverse and single longitudinal mode operation were observed because the built‐in optical waveguide was formed within the V channel.

ISSN:0003-6951    

DOI:10.1063/1.93107

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Photoetching of polymethyl methacrylate (PMMA) for pulsed high power UV light is demonstrated. As a high power UV light source, a KrF excimer laser was used. Etching depth obtained by deep UV light irradiation has not only energy dependence, but also power dependence. It increased abruptly by increasing the exposed power density for the same exposed energy density.These experimental results show that high power excimer lasers are the effective light source for UV photoetching of PMMA.

ISSN:0003-6951    

DOI:10.1063/1.93108

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Optically stimulated luminescence (OSL) from CaS:Eu,Sm and SrS:Eu,Sm phosphors, previously exposed to ionizing radiation, is shown to occur with response and decay times of less than 50‐ns full width at half‐maximum. This result indicates that fast high‐resolution OSL imaging of spatial dose distributions is possible via stimulation of the dose proportional luminescence with a tightly focused scanning laser beam. The two phosphors investigated are efficiently stimulated with the beam from a Nd:yttrium aluminum garnet (YAG) laser. The large dynamic dose range of these materials represents a distinct advantage of OSL imaging over conventional x‐ray radiography. In addition, the laser scanning technique readily lends itself to image digitalization and processing. Real‐time imaging appears feasible.

ISSN:0003-6951    

DOI:10.1063/1.93102

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The properties of a liquid‐solid interface are usually understood under the assumption that contact is continuous over the entire interface, regardless of the surface roughness of the solid. This letter presents results of an analysis which suggest that this assumption is not valid when the liquid is a metal characterized by weak adhesion to the solid. Under these conditions the true area of contact at the interface depends on the surface microtopology of the solid and may differ considerably from the area of nominal contact. Experimental evidence in support of these conclusions is presented.

ISSN:0003-6951    

DOI:10.1063/1.93109

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Spheres of the metallic glass Au55 Pb22.5 Sb22.5have been formed up to a size of approximately 1.5 mm in diameter. X‐ray diffraction was used to establish the glassy nature of the samples and to provide evidence of two phase‐separated glass regions. Scanning electron microscopy provided a direct visual observation of the two‐phase amorphous network on the surface of the sphere. The physical dimensions of the phase‐separated regions were observed to be cooling‐rate sensitive. Energy dispersive spectroscopy indicated that the compositions of these two glassy phases were Au‐rich and Pb‐rich, respectively, confirming the results of Kim and Johnson. In addition, the spheres exhibited an unusual surface smoothness of better than ±250 A˚.

ISSN:0003-6951    

DOI:10.1063/1.93110

出版商:AIP    

年代:1982

数据来源: AIP