摘要:

Experiments are described in which nitrogen and neon lasers are excited by a wave of current excitation which effectively travels from one end of the laser to the other with its velocity matching that of the stimulated emission. This type of excitation is accomplished with a low‐impedance flat‐plate Blumlein pulse generator. The power output in the direction of the wave of excitation is at least ten times that in the other direction. A 2.5‐MW pulse of about 4‐nsec duration is obtained with nitrogen and a 190‐kW pulse of about 1.5 nsec with neon.

ISSN:0003-6951    

DOI:10.1063/1.1754794

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The interaction between waves in an idealized saturable absorber is discussed. It is shown that the presence of a strong wave will cause the line to appear to be ``hole‐burned'' when probed by a second wave, even though the broadening mechanisms are conventionally homogeneous. This effect would be expected to work against the tendency of dye‐switched ruby lasers to operate in a single mode. Related effects should play a role in optical pulse generators and in other devices using saturable absorbers.

ISSN:0003-6951    

DOI:10.1063/1.1754798

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Experimental data is presented on the time behavior of a pulsed water‐vapor laser. Most of the far‐infrared emission lines from this laser showed quite rapid spiking. In addition, the lines showed significantly different time delays between the start of the current pulse excitation and the onset of laser oscillation.

ISSN:0003-6951    

DOI:10.1063/1.1754799

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Thin‐film zinc‐oxide microwave acoustic transducers have been formed successfully by vacuum deposition techniques upon a cooled substrate (−50°C) by evaporation of zinc with an oxygen beam. The films are hexagonal preferentially oriented withcaxis normal to the substrate. A device consisting of a ZnO film (1.9 &mgr;) deposited on a metallic film on a sapphire delay line had a one‐way conversion loss of 6 dB at 1.6 GHz with a large bandwidth indicating that zinc‐oxide thin films deposited by this method make good ultrasonic transducers at frequencies above 1 GHz.

ISSN:0003-6951    

DOI:10.1063/1.1754800

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The light intensity of a positive column in a longitudinal magnetic field changes with the field and becomes minimum at the critical field when a helical oscillation appears in the positive column. As this change is very steep at the critical point, even when the longitudinal electric field does not clearly show the point, an observation of the light intensity of the positive column may be useful in detecting the critical field value.

ISSN:0003-6951    

DOI:10.1063/1.1754784

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The energy spectrum of theD(d, p)Tprotons shows that with gold foils a surface and an inner part of imbedded deuterons exist, whereas solid gold gives only an inner part, solid copper and nickel only surface parts.

ISSN:0003-6951    

DOI:10.1063/1.1754785

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Optical and electrical measurements on thin sections of Bi4Ti3O12in orientations not previously measured have yielded the following results. The symmetry is monoclinic, point groupm.The spontaneous polarizationPsis greater than 30 &mgr;C/cm2and lies in a direction tilted slightly from the major crystal surface. Switching, with fields perpendicular to the major crystal surface, occurs by a small ``rocking'' of this largePsvector. The large component parallel to the major crystal surface can also be switched with high fields. Thus, there are four possible spontaneous polarization directions in the virgin crystal giving rise to complex domain structures.

ISSN:0003-6951    

DOI:10.1063/1.1754786

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

The special symmetry properties of second‐harmonic generation at the surface of a GaAs crystal are used in a technique which measures the shape of the fast pulses from a mode‐locked Nd‐glass laser. The pulses studied were found to have a full width at half power of between 4 and 6 picoseconds. The technique is capable of measuring pulse widths at least as short as 4 × 10−13sec.

ISSN:0003-6951    

DOI:10.1063/1.1754787

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

We have shown experimentally that light nuclei, including protons having energies as low as 55 keV, can produce etchable damage in cellulose nitrate. Comparison of our experimental results with theory indicates that the threshold for track registration is about 0.35 MeV per mg‐cm−2.

ISSN:0003-6951    

DOI:10.1063/1.1754788

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Described is a method of obtaining holograms of 3‐D objects illuminated in white light. First, a 3‐D scene, illuminated in white light, is photographed through a fly's eye lens. If this photograph is projected through the same lens it yields a real 3‐D image of the object directly. However, by using coherent light for projection, this real image can be used to make a hologram, which in turn yields both a real and a virtual image of the object.

ISSN:0003-6951    

DOI:10.1063/1.1754789

出版商:AIP    

年代:1967

数据来源: AIP