摘要:

Plasma‐polymerized films from hexamethyldisiloxane are suitable for giving a homeotropic alignment top‐methoxybenzylidene,p, n‐butylaniline. A 500‐Å‐thick layer of this polymer on substrates gives a very stable liquid crystal orientation.

ISSN:0003-6951    

DOI:10.1063/1.1655190

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The electrical and optical threshold voltages for the twisted nematic field effect have been measured using Schiff base mixtures having &Dgr;&egr; values from 2 to 16. The electrical threshold was measured by capacitance techniques, and was smaller than the optical threshold by a factor of ∼ 1.5. By using response time data to estimate changes in average elastic constants of the mixtures, the expected variation of the electrical threshold with &Dgr;&egr; was found.

ISSN:0003-6951    

DOI:10.1063/1.1655191

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

By using thermionic ion emission from a water glass (sodium silicate, Na2O · 2SiO2) an ion beam is easily produced in a plasma. Possible applications of the ion emission to plasma diagnostics are also described.

ISSN:0003-6951    

DOI:10.1063/1.1655192

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A region of strong electric field (i.e., a virtual cathode) is formed when a relativistic electron beam is forced to flow through a cavity. This region is located at the entrance of the cavity and significantly affects the behavior of the beam.

ISSN:0003-6951    

DOI:10.1063/1.1655193

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Passive mode locking of a TEA CO2laser usingp‐type germanium as a saturable absorber is described. Pulses of about 0.5‐ns duration are obtained.

ISSN:0003-6951    

DOI:10.1063/1.1655194

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

We have observed phase‐matched nonlinear mixing in a silica fiber optical waveguide using the dispersion of the guide modes to compensate for bulk dispersion. A tunable dye laser signal is mixed with a fixed‐frequency pump wave to generate output in specific waveguide modes at different frequencies. The technique is useful as a probe of waveguide properties and for the study of the nonlinearities of the medium.

ISSN:0003-6951    

DOI:10.1063/1.1655195

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

By means of optical phase shift measurements at low and high excitation levels, spontaneous and stimulated carrier lifetimes are determined (77°K) as a function of photon energy on nitrogen‐doped and nitrogen‐freen‐type GaAs1−xPx. Spontaneous lifetime data near laser threshold on N‐free samples show the effect of stimulated emission and intraband adjustment of electrons during sample fluorescence. Above threshold the lifetime drops sharply in the vicinity (energy or wavelength) of the sample peak laser output. Nitrogen‐doped samples show, in addition, the effect of electron transfer from the conduction band to the NN‐pair states, supporting in the process laser operation on the nitrogen states.

ISSN:0003-6951    

DOI:10.1063/1.1655196

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

An optical ``stopping effect'' on guided light in As&sngbnd;S films has been achieved using a He&sngbnd;Cd laser beam. Preliminary results of this newly found phenomenon are presented in this paper.

ISSN:0003-6951    

DOI:10.1063/1.1655197

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A 0.3‐GW, 60‐ns TEA CO2laser has been used to create plasma from a solid carbon target. Studies of the x‐ray emission from the plasma at 4×1011W/cm2indicate the existence of a high‐energy electron component with an equivalent temperature of ∼ 2 keV.

ISSN:0003-6951    

DOI:10.1063/1.1655198

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The effect of air exposure on the reflectance of evaporated amorphous and crystalline germanium for photon energies 2.5 ≤h&ngr; ≤ 11.7 eV has been studied in order to compare their oxidation rates. Forh &ngr; ≳ 4 eV, much larger changes in reflectance are observed in the amorphous films than are found in the crystalline films.

ISSN:0003-6951    

DOI:10.1063/1.1655199

出版商:AIP    

年代:1974

数据来源: AIP