摘要:

Low‐energy electron diffraction observations of a single crystal of &agr;‐alumina have revealed a reversible structural transformation on the (001) surface. The transformation is a function of the temperature of heat treatment of the alumina.

ISSN:0003-6951    

DOI:10.1063/1.1754883

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Reasonable quality holograms have been made of objects placed within 1 to 3 cm of the hologram plane without the need for any external reference beam. The reconstructions from such holograms, though not of high quality, are clearly recognizable and three‐dimensional.

ISSN:0003-6951    

DOI:10.1063/1.1754884

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Voltage‐biased superconducting weak contacts have been used as oscillating detectors to observe radio‐frequency absorption spectra including the Co59nuclear magnetic resonance in ferromagnetic cobalt. The detection is attributed to multiple quantum processes and differentiation of the dynamic I‐V characteristics. Used as a spectrometer, the point contact is shown to be a continusously tunable ultra‐low power oscillator‐detector from 0 to 3 × 108Hz. It is likely that the frequency limit could be extended to the superconducting gap frequency.

ISSN:0003-6951    

DOI:10.1063/1.1754885

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The possibility of observing the optical transient nutation effect in CO2lasers is considered. A formula for the nutation frequency is derived explicitly for the vibrational‐rotational transitions in molecules such as CO2.

ISSN:0003-6951    

DOI:10.1063/1.1754886

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Absolute frequencies of the 311‐&mgr; and the 337‐&mgr; transitions of the CN gas laser are measured to within a few parts in 107. This is achieved by mixing the laser frequencies with high order harmonics of a microwave signal in a silicon diode. The beat frequencies of these two transitions which falls at 73.5 GHz is also measured directly. The Zeeman effect of these two laser transitions is studied. Based on a detailed analysis, it is found that the existing identification of these transitions is inconsistent with our observations.

ISSN:0003-6951    

DOI:10.1063/1.1754887

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Visible three‐dimensional ultrasonic imaging of the interior and exterior of optically opaque objects has been achieved using a synthetic holographic technique at a frequency of 5 MHz. One ultrasonic hologram and the corresponding visible image are presented.

ISSN:0003-6951    

DOI:10.1063/1.1754888

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

We report detection and measurement of the millimeter wave difference frequency between two near laser lines at 1.152 &mgr;. The two spectral transitions, separated by 2.26 Å, oscillate in pure neon in a single laser device, producing about 150 &mgr;W total power in several longitudinal modes. The many resulting 51.3‐kmc beat frequencies have been studied by optical heterodyne techniques. A type of diode has been found which has enough microwave sensitivityandenough optical sensitivity to combine the optical detector and the microwave heterodyne functions in a single element. The preliminary value for the difference in frequency between the and 2S4→ 2P7transitions in neon at 150 mtorr is (51,360 ± 150) Mc. This value is not in agreement with the value calculated from Vol. I of Sitterly'sAtomic Energy Levels(ref. 12).

ISSN:0003-6951    

DOI:10.1063/1.1754889

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Photoconductivity has been observed inp‐type single‐crystal films of PbS. The results suggest that the photoconductive mechanism in these films is the same as that in the highly sensitivep‐type polycrystalline PbS detectors.

ISSN:0003-6951    

DOI:10.1063/1.1754890

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Highly complex stimulated Raman scattering (SRS) spectra of hydrogen were produced by using narrow linewidth 1.058‐&mgr; giant‐pulsed laser excitation. Results are presented which include the first reported observation of combination Raman lines whose frequencies are given bymvQ(1)+pvS(1)−vLwherevQ(1),vS(1)andvLare the vibrational (4155 cm−1), rotational (587 cm−1) and laser frequency, respectively,m= 6, 7, or 9 andp= 0 or ±1. Numerous Raman lines described by the formulav = vL+mvQ(1)+nvS(0)+pvS(1), (m, n, p= 0, ±1, ±2,…), wherevS(1)= 354 cm−1, were also observed.

ISSN:0003-6951    

DOI:10.1063/1.1754891

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Laser activity has been obtained from terbium tris (1, 1, 1‐trifluoroacetylacetonate) at room temperature in a liquid solution in acetonitrile and inp‐dioxane. Threshold pumping energy is about 1700 J. Characteristic line narrowing, spiking and beam collimation was exhibited.

ISSN:0003-6951    

DOI:10.1063/1.1754892

出版商:AIP    

年代:1967

数据来源: AIP