摘要:

The composition of anodically and thermally grown silicon oxide layers was determined by backscattering and channeling measurements with 2.0‐MeV4He+ions. The oxide thickness was determined by ellipsometry and, for anodic films, the silicon removal rate was also determined by layer removal measurements. The surface layer consists of stoichiometric silicon dioxide plus a silicon‐rich transition layer between the substrate and the silicon dioxide. The number of silicon atoms in this layer was found to be 6 × 1015atoms/cm2(about three atomic layers).

ISSN:0003-6951    

DOI:10.1063/1.1655112

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A new material, Tl3PSe4, has been grown as a single crystal and studied for its optical and optoacoustic properties. It is transparent over the range 0.85–17 &mgr;m and has an optoacoustic figure of merit (relative to fused silica) of 1370 (at 1.15 &mgr;m). The slow shear wave acoustic velocity is 5.1×104cm/sec, the lowest recorded in the literature for a solid or a liquid. The low velocity and high refractive index (n≈ 3) lead to the high figure of merit.

ISSN:0003-6951    

DOI:10.1063/1.1655113

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The technology for fabrication of submicron bulk platelet transducers has been developed. Lithium niobate (LiNbO3) transducers with thicknesses as low as 0.25 &mgr;m have been achieved. This technology employs a novel bonding technique, the room‐temperature vacuum bond, and a carefully controlled process of ion‐beam milling. Bulk wave acoustic delay lines consisting of LiNbO3transducers on spinel (MgAl2O4) substrate have yielded very wide‐band and low‐loss operation inS‐,C‐, andX‐band frequencies.

ISSN:0003-6951    

DOI:10.1063/1.1655114

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A 500‐keV 40‐kA 50‐nsec‐duration relativistic electron beam is propagated through a cusped magnetic field. Conditions are reported which allow more than 85% of the beam energy to pass through the cusp.

ISSN:0003-6951    

DOI:10.1063/1.1655115

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A new method for delineation of surface discharge figures on insulating surfaces is described. Cholesteric liquid crystal thin films on insulating surfaces finely delineate structures of residual charges of surface discharges on them. The method has high resolving power (∼ 1 &mgr;m) in the delineation of the surface discharges.

ISSN:0003-6951    

DOI:10.1063/1.1655116

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

We have observed thermal blooming of focused 10.6‐&mgr; laser radiation in the transient regime where the index changes are dominated by the hydrodynamic response of the medium. In this regime (where the time is less than one‐half of the hydrodynamic time in the focal plane) it is seen that the approximation wherein the refractive index is proportional tot3gives an adequate agreement with the experimental observations.

ISSN:0003-6951    

DOI:10.1063/1.1655117

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

cw output of 1.1 W was attained from a compact (14‐cm discharge length, 2‐mm bore diameter tube) sealed‐off CO waveguide laser operating in the HE11mode. The BeO laser tube, cooled to 210 °K, was operated at the 1‐W level for more than 4 h without output degradation and with a 5.7% efficiency. A mixture of CO:He:Xe:N2in the ratio of 1:8:1:1, at a total pressure of 80 Torr, was found to be optimum, confirming the scaling or similarity rule of the product of optimum pressure and tube diameter for CO at this temperature. The output spectrum consisted of about 10 lines, between 5.20 and 5.65 &mgr;. Laser operation without N2(1:8:1:0) was also observed. Black particles found in the tube were x‐ray identified as Ni plus NiO, indicating sputtering from the Ni cathode.

ISSN:0003-6951    

DOI:10.1063/1.1655118

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A resonant reflector made of germanium is reported which allows selection of one single rotational line out of a TEA CO2laser. The reflector has to be temperature stabilized within ± 0.1 °C. Selection of one, two or three rotational lines simultaneously is possible by varying the temperature.

ISSN:0003-6951    

DOI:10.1063/1.1655119

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Schottky diodes were used as collectors in the determination of bulk hole diffusion lengths (Lhn) by means of a scanning electron microscope in the beam‐induced current mode. The scans were performed on cross sections obtained by cleavage along a plane perpendicular to the metal layer. Forn‐type GaP this technique yields excellent results.

ISSN:0003-6951    

DOI:10.1063/1.1655120

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The Ga1−xAlxAs laser diodes which emit a wavelength of 6190 Å at 77 K with threshold current densities as low as 300 A/cm2were fabricated using a double heterostructure with lightly doped active regions. This lasing wavelength is the shortest ever attained in Ga1−xAlxAs lasers for such a low threshold current density. The maximum external quantum efficiency of these diodes was found to be about 35% at 77 K. The extensive studies made of the properties of these visible‐light‐emitting lasers, especially of the spectral distributions, are described in full detail.

ISSN:0003-6951    

DOI:10.1063/1.1655121

出版商:AIP    

年代:1974

数据来源: AIP