摘要:

The properties of cooled AlxGa1−xAs heterojunction laser diodes operating at wavelengths below 7000 Å are described. At 77 K, the shortest wavelength at which pulsed laser operation is obtained is 6280 Å, while convenient cw operation has been obtained to 6570 Å. Pulsed laser diode operation to 6770 Å was obtained up to 223 K.

ISSN:0021-8979    

DOI:10.1063/1.1662925

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Calculations are presented which follow the time evolution of the energy distribution function of electrons interacting with an extensively preionized He gas and a CO2laser photon field. Explicit account is taken of electron‐electron collisions, inelastic and superelastic collisions between electrons and excited species, and inverse bremsstrahlung in the field of ions and neutrals. Computed breakdown thresholds are in agreement with recent data of Brown and Smith.

ISSN:0021-8979    

DOI:10.1063/1.1662926

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A thin cylinder above a finitely conducting half‐space is illuminated by a monochromatic plane wave. The electric vector of the incident plane wave is parallel to the axis of the cylinder and the Poynting vector of this incident plane wave intersects the surface of the finitely conducting half‐space at an oblique angle. An imperfect image is used to derive the total current on the thin cylinder and the electric field at the surface of the half‐space. The total induced current on the thin cylinder is shown to reduce to the appropriate limiting form when the height or the half‐space conductivity becomes infinite.

ISSN:0021-8979    

DOI:10.1063/1.1662927

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A fast‐ion current peak, measured with an ion collector placed in the path of an expanding laser‐produced plasma, was identified as carbon, nitrogen, and oxygen contaminants which originated from a tungsten target surface.

ISSN:0021-8979    

DOI:10.1063/1.1662928

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A longitudinal electron beam was used to provide the preionization for a TEA‐type CO2laser. Single‐line energy in excess of 10 J/liter at 10.6 &mgr;m can be obtained from this laser in approximately 2 &mgr;sec. This device may be simply converted to one previously reported which uses the electron beam to provide the total ionization required for laser excitation and emits 20–120‐&mgr;sec pulses of comparable energy.

ISSN:0021-8979    

DOI:10.1063/1.1662929

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The luminescence of vapor‐grown GaN doped with Be or Mg shows deep emission bands in the yellow‐green (Be) or blue‐violet (Mg) wavelength regions in addition to the near‐gap features previously recognized in Zn‐ and Cd‐doped GaN. The crystals are of high resistivity at high Be or Mg doping levels.

ISSN:0021-8979    

DOI:10.1063/1.1662930

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The time evolution of holes drilled in fused quartz with a cw CO2laser has been determined. It is shown that drilling proceeds by a complex balance between absorption and channeling of incident radiation. During drilling, the tip of the hole is often far removed from the optical axis and appears to propagate along a helical path on moving into the target.

ISSN:0021-8979    

DOI:10.1063/1.1662931

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Ann→ptransition has been observed for &agr;‐tin filaments irradiated with 0.675‐MeV electrons at 5 K. Resistance and thermoelectric emf measurements were used to establish that the electron dose needed to effect then→ptransition is roughly proportional to the impurity concentration forn‐type material. No transition was observed forp‐type material. The data are interpreted in terms of radiation‐induced trapping levels.

ISSN:0021-8979    

DOI:10.1063/1.1662932

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Deposition of silicon onto a clean Be (0001) surface results in an ordered superstructure which is characterized by the presence of (1/3)‐order spots in the low‐energy electron diffraction pattern of the clean surface. This is the√3×√3−30°structure that was predicted in an earlier report. Epitaxial growth of crystalline Si films is hindered, however, at low temperatures by the low mobility of the adsorbed atoms (the Si films are amorphous) and at high temperatures by the rapid diffusion of Si into the interior of the substrate.

ISSN:0021-8979    

DOI:10.1063/1.1662933

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The deposition of epitaxial EuS films on mica is reported. The structure and orientation of the films on the mica surface are determined by transmission Laue photographs.

ISSN:0021-8979    

DOI:10.1063/1.1662934

出版商:AIP    

年代:1973

数据来源: AIP