ISSN:0003-6951    

DOI:10.1063/1.1754869

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

A ferroelectric triglycine sulfate crystal was illuminated by an intense CW laser beam; light scattered by the crystal at right angles to the beam was observed visually and photographed. The visible scattering column was found to be crossed by a series of bright lines oriented parallel to the ferroelectric axis whose appearance under various electric field and temperature conditions strongly suggest that they correspond to boundaries of ferroelectric domains. It therefore appears that this technique will permit direct observation of domain dynamics which, in the past, has been possible only with indirect techniques.

ISSN:0003-6951    

DOI:10.1063/1.1754870

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

An experiment is described in which 350 mW of single‐frequency light at 5145 Å was obtained using an argon FM laser with an external LiNbO3modulator. Data on overall conversion efficiency from multifrequency to single‐frequency light are presented. Also discussed is the reduction in distortion with increasing optical power. Total sideband content was less than 0.125% of the maximum optical power, corresponding to an ac ripple of 3.5% rms.

ISSN:0003-6951    

DOI:10.1063/1.1754871

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The use of photon‐modulated tunneling for photodetection is demonstrated in a structure of Te&sngbnd;Al2O3&sngbnd;Al. Compared with the response of the Te alone, measuredin situ, the tunnel‐barrier device is much faster; the detectivity and the spectral response are similar.

ISSN:0003-6951    

DOI:10.1063/1.1754872

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Space‐charge‐limited currents were studied onp‐type silicon in the resistivity range from 10000–50000 &OHgr;·cm.IvsVcharacteristics showed regions where the current was proportional toV, Vn(1 <n< 2),V2,V3and to expV, depending upon the applied field strength. Hall measurements were taken over the entire current range. Due to the large lifetime, a minority carrier space charge is built up at low values of an electric field. Further increases of the applied field lead to double injection.

ISSN:0003-6951    

DOI:10.1063/1.1754873

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The occurrence of epitaxial growth of single‐crystal films of silver and gold has been found to depend critically on exposure of the substrate surface to an electron beam prior to deposition. Single‐crystal films with a (100)∥(100), (100)∥(100) orientation were produced on irradiation surfaces at low supersaturation levels in the absence of contaminating gases. It is proposed that the controlled production of point defects on the clean surface play a critical role in the nucleation and growth required for epitaxy.

ISSN:0003-6951    

DOI:10.1063/1.1754874

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

This Letter reports a new class of arc columns in the torr‐pressure range which in a wide range of voltages are voltage‐determined. The arc columns consist of mixtures of some noble gas seeded with tiny amounts of alkali vapor (pressure about 3 × 10−4torr). At a certain critical current a very strong rise, by a factor of 4 or more, in column gradient occurs, accompanied by very striking visual changes in the column. An explanation in terms of the concept of ``donor depletion'' is given, the ``donor'' atoms being the alkali atoms. Possibilities for practical applications are mentioned.

ISSN:0003-6951    

DOI:10.1063/1.1754875

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

In all the infrared quantum counter systems reported to date, a single rare‐earth ion dopant was used as the activator. This limits the optimum concentration to about 1%, since above this value nonradiative processes begin to dominate. In order to increase the number of ions which can absorb the infrared signal Yb3+was used as a sensitizer. By making use of the energy transfer from Yb3+to Ho3+the green quantum counter fluorescence was increased by more than two orders of magnitude.

ISSN:0003-6951    

DOI:10.1063/1.1754876

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Hall voltage and conductivity of semiconducting CdS crystals with different mobilities have been measured at high pulsed electric fields. The electron density is nearly constant in a wide range of field which includes the field of current saturation. At fields above 2.1 × 103V/cm, electron multiplication due to impact ionization is observed. In the case of an electric field parallel to thecaxis of the crystal, the Hall drift velocity at the saturation field is determined by the interaction of electrons with off‐axis shear waves of sound.

ISSN:0003-6951    

DOI:10.1063/1.1754877

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

A technique is described for measuring the photon absorption coefficients in the active and passive regions of an electron‐beam‐pumped semiconductor laser. Measurements made at 4°K onn‐type, single‐crystal GaAs indicate that photon loss in the active region is due to free carrier absorption, and that this absorption coefficient increases linearly from 2.5 cm−1to 47 cm−1as donor concentration is varied from 2.4 × 1017cm−3to 4.7 × 1018cm−3. For each case the active region absorption coefficient is less than that measured in the passive region, which varies from 354 cm−1to 98 cm−1over the same range of donor concentrations. The increased loss in the passive region is attributed to interband absorption transitions.

ISSN:0003-6951    

DOI:10.1063/1.1754878

出版商:AIP    

年代:1967

数据来源: AIP