摘要:

The surface composition of evaporated Au(98%)&sngbnd;In(2%) alloy films has been investigated by Auger electron spectroscopy. Sputter etching showed the surface concentration to be markedly different from the bulk concentration. The In concentration on a freshly sputter‐etched surface increases with time and reaches an equilibrium value of [inverted lazy s] 15 at.%, at room temperature. This In‐enriched surface is believed to have the thermodynamically stable composition.

ISSN:0003-6951    

DOI:10.1063/1.1654987

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A new method of applying channeling to determine the number of displaced atoms in an ion‐implanted silicon sample is described. The technique utilizes measurements of the transmission energy spectra of channeled protons scattered 10° from the incident beam direction as they penetrate through thin ([inverted lazy s] 1 &mgr;m) silicon crystals to discriminate between ``true'' interstitial atoms and atoms only slightly off lattice sites due to strain. A comparison of this technique with the standard channeling effect technique, using backscattering, indicates that the channeling‐backscattering technique is sensitive mainly to such ``true'' interstitial atoms.

ISSN:0003-6951    

DOI:10.1063/1.1654996

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

An anisotropic quasistatic stress distribution is found in the material surrounding an absorbing inclusion of a radiusacentered a distancedbelow the surface of a transparent host. Maximum tensile stress greater than the pressure at the inclusion‐host interface occurs at the angle &THgr;m= cos−1(a/d) from the line joining the inclusion center to the surface, resulting in cone‐shaped fracture.

ISSN:0003-6951    

DOI:10.1063/1.1655003

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Uniform Schottky barrier avalanche photodiodes with gains greater than 250, rise times less than 200 psec, and good quantum efficiencies at 1.06 &mgr;m have been fabricated in InxGa1−xAs alloys. The material used for these devices was grown epitaxially on GaAs substrates using an AsCl3&sngbnd;H2&sngbnd;Ga&sngbnd;In vapor‐phase system which permitted grading the epitaxial layers from GsAs to the desired composition.

ISSN:0003-6951    

DOI:10.1063/1.1655004

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Room‐temperature laser action is reported in Nd3+: CeCl3. The observed threshold was 0.06 J compared to 0.13 J for Nd3+: YAG. Stronger pump bands and higher laser transition cross sections of neodymium‐doped anhydrous trichlorides of cerium and lanthanum render these materials superior to Nd3+: YAG for miniaturized and thin‐film laser applications.

ISSN:0003-6951    

DOI:10.1063/1.1654988

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

X‐ray emission from the 2s→ 1stransition in hydrogenic ions stimulated by an optical laser is proposed as a means of achieving lasing action in the x‐ray region. A net gain of 0.27 cm−1is calculated for the 18.97‐Å 2s→ 1stransition of O+7at an inverted population density of 1015ions/cm3in the presence of a Nd laser field of 5 × 108W/cm2.

ISSN:0003-6951    

DOI:10.1063/1.1654989

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Population inversions for optical transitions in the VUV and soft x‐ray spectral region are predicted theoretically for decaying plasmas. The calculations are based upon a quasisteady‐state theory for hydrogenlike ions. In contrast to other approaches it is shown that the characteristic relaxation time to generate inversions is not that of the corresponding upper levels but that of the ground state of the ions, i.e., the relaxation time for recombination. A plasmadynamic laser system for cw operation in the VUV is proposed.

ISSN:0003-6951    

DOI:10.1063/1.1654990

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

This paper reports new observations in degraded (Al · Ga)As double‐heterostructure (DH) laser diodes and proposes a mechanism of short‐term ([inverted lazy s] 100 h) degradation characteristic to DH structures. Degradation is seen localized as ``dark lines'' of certain crystalline orientations in electroluminescent patterns, as well as junction current patterns using an SEM. X‐ray measurement showed internal strain due to heteromismatch. It is suggested that the internal stress accelerates development of the dark lines, which is likely to be a crystalline defect caused by thermal stresses.

ISSN:0003-6951    

DOI:10.1063/1.1654991

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A low‐driving‐voltage optical modulator with the configuration of an optical waveguide has been fabricated. A LiTaO3single crystal with a thickness of 40 &mgr;m was used as the core and was cladded with a thin film of CeO2formed by evaporation. The extinction ratio was better than 2%.

ISSN:0003-6951    

DOI:10.1063/1.1654992

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A second tunnel layer and an interference layer are added to a prism‐film coupler. The resulting frequency response of the leak rate is given by the Airy formula for an interference filter. Strong coupling exists in the passband, whereas for stopband frequencies the guide and prism are decoupled. Experimentally, a bandwidth of 300 cm−1in the visible is demonstrated. The underlying principle is also applicable to periodic couplers.

ISSN:0003-6951    

DOI:10.1063/1.1654993

出版商:AIP    

年代:1974

数据来源: AIP