摘要:

We report on three techniques for replicating relief patterns in dielectric materials for use as substrates for planar integrated optical circuits: embossing with a metal die; casting from a metal die; and casting from a rubber mold. Techniques for overcoating the substrates with light‐guiding films and filling of grooves are also described. Measured losses in sheet film guides were ≤0.5 dB/cm. Guiding was also observed in narrow light guides fabricated by each technique. Embossing is the simplest process, but for small‐scale production the casting processes are simpler to implement.

ISSN:0021-8979    

DOI:10.1063/1.1663087

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

An experimental investigation has been carried out to confirm that contact noise of two crossed semiconductor bars with native oxide films in between can be understood as a volume 1/fnoise. Noise and contact resistance have been measured as functions of the forceFon the crossed bars.Fvaries between 6 N and 6×10−5N. From a simple model, an equation is derived which relates the 1/fnoise intensityCto the contact resistanceR. The calculations are in agreement with the experimentalC‐Rplots. Two extreme situations are possible: constriction dominated and film dominated. Which situation actually occurs can be seen in theC‐Rplot as well as in theR‐Fplot.

ISSN:0021-8979    

DOI:10.1063/1.1663088

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The spectral dependence of the fundamental absorption edge of congruently grown undoped LiNbO3has been measured from 10 to 667 K. Similar measurements on stoichiometric samples were made at 80 and 300 K. In all cases at all temperatures the edge is broad and featureless and showed very little dichroism (<0.01 eV). The spectral dependence of the absorption is exponential at high temperatures but not at low temperatures. Possible models to explain the observed shapes are discussed.

ISSN:0021-8979    

DOI:10.1063/1.1663089

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Detailed numerical calculations of electron transport coefficients and vibrational excitation rates in a He:N2:CO2gas laser discharge have been carried out over a range 1×10−16≤E/N≤5×10−16V cm2for several gas mixtures. Comparison of the results indicate that the vibrational excitation processes in the CO2molecule scale with the average electron energy and are approximately invariant with respect to gas mixture. At a fixed value of electron energy, the dominant effect of gas mixture variation is to modify the vibrational excitation rate into the nitrogen. The effect of gas mixture variation on electron drift velocity is greatest in CO2&sngbnd;He mixtures, but is substantially reduced when a small fraction of N2is added.

ISSN:0021-8979    

DOI:10.1063/1.1663090

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Accurate electrical and analytical measurements allowed us to determine a relationship between resistivity and phosphorus concentration in doped silicon. This relationship is compared with that obtained by other authors in the case ofn‐type silicon, and the differences due to the various doping agents are discussed. Differences between concentrations determined by analytical techniques and by Hall effect measurements are reported.

ISSN:0021-8979    

DOI:10.1063/1.1663091

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A model relating the nucleation field forRCo5particles (Rstands for any rare‐earth element) to the domain‐wall energy has been refined and it now predicts some interesting experimentally observable effects. The experimental verification of the predicted effects puts the model on a strong experimental foundation. The model explains the origin of the superior magnetic properties for SmCo5particles observed at the Air Force Materials Laboratory.

ISSN:0021-8979    

DOI:10.1063/1.1663092

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Phenomenological anisotropy constants have been measured in three garnet bubble films with their surface normal slightly misoriented from the crystallographic [111] direction. A tilted magnetic easy axis is found from measurements of homogeneous nucleation and bubble collapse in the presence of in‐plane fields. An in‐plane anisotropy is also found whose axes do not in general lie either normal to or in the easy‐axis tilt plane. These results are shown to be consistent with a phenomenological growth anisotropy model which includes the film plane misorientation.

ISSN:0021-8979    

DOI:10.1063/1.1663093

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

By sputtering and evaporation simultaneously, &bgr;‐W phases Nb3In, Nb3Pb, and Nb3Tl have been prepared. Lattice constants were measured for all samples and found to increase with decreasing substrate temperatures. These values were respectively: 5.303±0.002 A, 5.333±0.005 A, and 5.297±0.005 A. The extended range in producing unstable phases by film‐deposition techniques as opposed to conventional methods is considered.

ISSN:0021-8979    

DOI:10.1063/1.1663094

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The superconducting and mechanical properties of multifilament Nb3Sn wires prepared by the surface diffusion technique are described. Materials tested were 0.021‐ and 0.051‐cm‐diam wires with 392 filaments 6.6 or 16 &mgr; in diameter. Electron microprobe and scanning electron microscope studies of Nb3Sn layer thickness and matrix contamination have been carried out also.

ISSN:0021-8979    

DOI:10.1063/1.1663095

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A simplified equation was derived by which the uniaxial anisotropyHKof the usual bubble materials can be determined from the field lying in the plane of the sample at which the domains disappear. It was found that a garnet film epitaxially grown on a (111) plane of Gd3Ga5O12shows a sixfold symmetry of the domain erasing field which may be due to the cubic crystalline anisotropy of the sample. This implies that, if the cubic anisotropy cannot be neglected compared to the uniaxial anisotropy, the crystallographic axis in the plane of the film along which the domain erasing field is to be applied should be carefully determined. An estimation was made on the contribution of the cubic anisotropy to the domain erasing field when the field lies along a [110] axis.

ISSN:0021-8979    

DOI:10.1063/1.1663096

出版商:AIP    

年代:1974

数据来源: AIP