摘要:

The decay of temperature transients in pulse‐heated sheet targets can be analyzed to deduce the initial magnitude and spatial distribution of target heating. We present formulas describing such thermal transients, and give an example of analysis involving heating of aluminum by a pulsed CO2laser with air plasma ignition. Plasma spreading of heat deposition over an area much larger than the laser beam cross section is shown.

ISSN:0003-6951    

DOI:10.1063/1.89707

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

When highly ionized impurities are present in a plasma, the scattered spectrum of the major ion species can be distorted in a complicated way. A method is given by whichTe/Tiand Z¯ (≡Jnjzj2/ne) can be measured which does not require any knowledge of the mass, charge state, or concentration of the impurity species. A generalization of the Salpeter approximation for the integrated cross section is proven. The result is that the total cross section is a function of &agr; (≡ 1/K&lgr;D),Te/Ti, and Z¯ as long as the temperature of all ion species is the same andTe/Tiis not too large. Thus a measurement of the integrated ion cross section at two different scattering angles can yieldTe/Tiand Z¯. This method is insensitive to magnetic fields and to moderate electron drifts. For 1≲Te/Ti, Z¯≲3 the cross section must be measured to an accuracy of about 3% to giveTe/Tito within 10% and Z¯ within 20%.

ISSN:0003-6951    

DOI:10.1063/1.89708

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Diffusion of Tl+ions was determined in a multicomponent glass by means of an ion‐exchange technique. Diffusion coefficients of Tl+ions of 9.86×10—7to 4.34×10−10cm2/sec were calculated for glass which was immersed at 450 °C for 24 h in TlNO3‐KNO3molten salts with the composition Tl/(Tl+K) =0.1 to 0.5.

ISSN:0003-6951    

DOI:10.1063/1.89709

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

A new phase-tuning method for an optical directional coupler is proposed. The method involves using the refractive-index change induced by a light exposure (<0.5 &mgr;m) of (Se-S) -based chalcogenide glass film loaded on the waveguides. The light coupling in a directional coupler, fabricated in ac-plate LiNbO3, was changed from 95 to 15% by irradiation of a halogen lamp.

ISSN:0003-6951    

DOI:10.1063/1.89710

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

The transmitted light from side‐illuminated transparent optical fiber taper couplers is analyzed. A direct measure of the slope and the diameter variations of the taper is obtained with ease from the deflected (refracted) beam and the displayed far‐field diffraction pattern.

ISSN:0003-6951    

DOI:10.1063/1.89711

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

cw laser action in Na+‐doped KCl and RbCl crystals containingFB(II) centers is reported. The total tuning range was 2.25⩽&lgr;⩽2.9 &mgr;m. Pump power at threshold was measured to be 20 mW and an output power of 18 mW was obtained. It is expected that the wavelength range for this type of laser can be extended into the 3–4‐&mgr;m region with RbBr and RbI crystals.

ISSN:0003-6951    

DOI:10.1063/1.89712

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Single‐crystal Cr‐doped Al2O3fibers can be grown by a floating‐zone technique from small source rods locally melted at the end by a CO2laser. By using the same laser to melt and regrow only the surface of the fiber, the Cr concentration in this surface layer can be reduced by a factor of 100 or more by selective evaporation.

ISSN:0003-6951    

DOI:10.1063/1.89713

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Cross sections for production of excited states of Cd II resulting from He+‐Cd and He+2‐Cd collisions are reported. These data suggest that high‐pressure (∼ atmospheres) operation of a He‐Cd laser in which pumping is achieved by charge‐transfer excitation with reactant He+2might be possible. Selective population of the (4d)9(5s)2 2D3/2level in He+2‐Cd collisions produces enhancement of the 325.0‐nm line relative to the 441.6 nm.

ISSN:0003-6951    

DOI:10.1063/1.89714

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

A 90° polarization rotator for use at 347 nm was constructed and successfully tested at peak intensities in excess of 15 MW cm−2. This liquid optical rotatory device (LORD) employs aqueous solutions of sucrose to rotate the plane of polarization of the incident beam, may be tuned to other incident wavelengths, and should be widely useful for applications involving both tunable dye lasers and high‐power lasers.

ISSN:0003-6951    

DOI:10.1063/1.89701

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Blue picosecond length pulses have been produced by a short‐cavity dye laser, axially pumped with the third harmonic of a mode‐locked Nd+3 : glass laser. Tuning was conveniently achieved by tilting the laser. Performance was investigated for cavity lengths ranging from 10 to 150 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.89702

出版商:AIP    

年代:1977

数据来源: AIP