摘要:

Laser action at 10.6 &mgr;m has been obtained in pure CO2gas at pressures up to 1 atm by optically pumping with the 4.23&mgr;m line of a TEA HBr laser. The potential usefulness of this method for pumping very high density CO2is discussed.

ISSN:0003-6951    

DOI:10.1063/1.1654199

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

A simple off‐axis hologram has been recorded on thin bismuth film using a train of picosecond pulses from a mode‐locked Nd: glass laser. Due to the ultrashort pulse duration and temporal coherence length of the laser, a time‐of‐arrival principle is utilized to show the correspondence of a point on the hologram to some specific region of the object.

ISSN:0003-6951    

DOI:10.1063/1.1654201

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Laser melt quenching has been used to obtain high cooling rates comparable to those obtained by ``splat cooling'' techniques. By measurements of dendrite spacing, the average cooling rate in a laser‐melted aluminum alloy was determined to be 3.7×106°C/sec. Laser melt quenching applied to a Ag&sngbnd;Cu alloy suppressed the two‐phase equilibrium eutectic structure and resulted in the formation of a single‐phase solid solution.

ISSN:0003-6951    

DOI:10.1063/1.1654202

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

dc electrical power deposition in CO2closed‐cycle electric‐discharge convection lasers (EDCL) can be increased to levels characteristic of open‐cycle performance by the application of rf (13.7‐MHz) auxiliary power. Experiments have been conducted with the radio frequency capacitively coupled into the discharge zone transverse to the dc field through the top and bottom walls of a rectangular laser channel. The effect of rf power on the dc power level and on the small‐signal gain coefficient is described.

ISSN:0003-6951    

DOI:10.1063/1.1654203

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

A giant pulse of a ruby laser is focused into water, silicone oils, and some other liquids. High‐speed photography of the focal region with picture repetition rates up to 850 000 pps shows the dynamics of the produced bubbles. These are extremely well suited to study cavitation bubble dynamics. Spherical almost empty bubbles can be produced in water, realizing the Rayleigh bubble model. The shock wave produced by the laser‐induced breakdown is made visible by small bubbles suspended in the vicinity. From the radial motion of these bubbles, conclusions can be drawn on the strength of the shock wave.

ISSN:0003-6951    

DOI:10.1063/1.1654204

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Single crystals of LiF, Al, and graphite have been studied by x‐ray diffraction while undergoing shock‐wave compression to about 300 kbar. These studies show that single crystals can transform to the hydrostatically compressed state essentially as single crystals, and crystal orientation is preserved.

ISSN:0003-6951    

DOI:10.1063/1.1654205

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The methods of holographic interferometry have been applied to the study of dynamic phenomena on a microscopic scale. The developed system has a spatial resolution in the 10‐&mgr; range and a temporal resolution in the submicrosecond regime.

ISSN:0003-6951    

DOI:10.1063/1.1654206

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Previous measurements on the backscattered light from a laser‐produced plasma, showing a line structure, have been incorrectly interpreted. New experiments reveal a shift of the backscattered light together with considerable broadening.

ISSN:0003-6951    

DOI:10.1063/1.1654207

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

It was found that the color fading rate of a photochromic film is accelerated when it is exposed to an acoustic field. The investigation of the effect was made with acoustic waves both in water and in air. This newly found effect was utilized as a novel means of mapping an acoustic field. It was shown that the effect can be used to map not only acoustic waves in a liquid, but also acoustic waves generated on the surface of an ADP (ammonium dihydrogen phosphate) crystal. In addition, an acoustic hologram of a small object in water was recorded using this effect.

ISSN:0003-6951    

DOI:10.1063/1.1654208

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Landau‐Lifshitz damping parameters deduced from domain wall mobility measurements are reported for a number of rare‐earth iron garnets. These damping parameters are compared with the ones obtained from ferrimagnetic resonance experiments.

ISSN:0003-6951    

DOI:10.1063/1.1654209

出版商:AIP    

年代:1972

数据来源: AIP