摘要:

Experiments have been carried out which show that the electrical breakdown of gases by optical frequency radiation is independent of the instantaneous intensity fluctuations arising from the interaction of modes present in laser radiation. Gas breakdown thresholds, determined with a single‐mode ruby laser and a phase‐locked neodymium laser are in substantial agreement with published threshold data for conventional, multiple‐mode laser radiation. It was thus determined that the breakdown threshold does not depend upon short term temporal and spatial fluctuations of the power density.

ISSN:0003-6951    

DOI:10.1063/1.1755041

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Field‐electron emission patterns below and above the solid‐phase transformation temperature in hafnium are presented. The transformation temperature was found to be 2030°K confirming results obtained by other methods.

ISSN:0003-6951    

DOI:10.1063/1.1755042

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

In high precision holographic imagery of weak objects of small angular subtense, electronic detection and digital image formation have distinct advantages. Experiments with a vidicon detector and a PDP‐6 computer have yielded reconstructed images of good quality with computation times of five minutes.

ISSN:0003-6951    

DOI:10.1063/1.1755043

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The Faraday effect has been studied in a high Verdet‐constant terbia‐alumina‐silicate glass containing 58% Tb2O3by weight at a number of temperatures down to 2.08°K using the 6328 Å light from a helium‐neon laser. The glass is found to be antiferromagnetic with a Curie temperature of ‐1.16°K. At 2.08°K the observed rotation as a function ofH/Tfits the Becquerel equation&thgr; = Atanh (&mgr;eH/kT) +BH, where &mgr;eis 3.5 Bohr magnetons. Because of this small Curie temperature the low‐field Verdet constant above liquid nitrogen temperatures follows the simple Curie law within experimental error.

ISSN:0003-6951    

DOI:10.1063/1.1755044

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Efficient visible light emitting diodes have been fabricated from Ga1‐xAlxAs. Epitaxial layers were obtained by a modified solution growth technique. External quantum efficiencies of up to 3.3% have been measured at room temperature on diodes, which had their emission at 1.70 eV. The switching time for the light emission at 300°K was measured to be 60 nsec.

ISSN:0003-6951    

DOI:10.1063/1.1755045

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

By measuring the steady‐state potential distribution inn—GaAs samples with ohmic contacts, very high electric fields have been found near the anode contacts. In samples withn · L(carrier concentration × sample length) products greater than 1012cm‐2, switching from the Gunn mode to a high current, lower (constant) voltage state takes place along with the appearance of a high field at the anode. In samples withn · Lproducts less than 1012cm‐2the buildup of the high field is accompanied by a sudden increase in current. These high currents are due to carrier generation in a narrow region near the anode.

ISSN:0003-6951    

DOI:10.1063/1.1755046

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

A new nondestructive method is reported to investigate electromigration‐induced void formation in aluminum stripes on silicon substrates. X‐ray topography and optical microscopy are employed to characterize void nucleation at or below the film surface. Results are presented to show the correlation between x‐ray and optical images of void structures in an aluminum stripe after dc current flow.

ISSN:0003-6951    

DOI:10.1063/1.1755047

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

PassiveQ‐switching of a CO2&sngbnd;N2&sngbnd;He laser has been obtained, using SF6gas as the saturable absorber. Peak power is 1 kW, in what appears to be a single transverse mode. This is 200 times the CW level for the same configuration and one‐fifth that obtained with a mechanicalQswitch. Pulse rates are in the range 103to 104pulses per sec. Operation is on a single vibrational‐rotational line, unlike the case of CW operation.

ISSN:0003-6951    

DOI:10.1063/1.1755048

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Two organic dyes previously used as liquid lasers, DTTC and cryptocyanine, have been used as broad‐band (>300 Å) pulsed light amplifiers in the 7000–8500 Å range. If the input frequency is close to the frequencies of the usual laser oscillations, the latter are quenched and the energy transferred to the frequency being amplified.

ISSN:0003-6951    

DOI:10.1063/1.1755049

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Hall effect and sheet resistivity measurements combined with layer removal techniques indicated carrier concentrations for 20‐kV antimony implants into silicon that exceed the thermal equilibrium solubility. Annealing caused the carrier concentration to decrease toward solubility values. Supersaturation effects were not observed for gallium implants. For samples annealed at 800 to 900°C, the concentration of carriers increased linearly with implanted dose and leveled off at a value close to the thermal equilibrium solubility.

ISSN:0003-6951    

DOI:10.1063/1.1755050

出版商:AIP    

年代:1967

数据来源: AIP