摘要:

The radiation‐induced optical attenuation has been measured over a wide range of dose and time in state‐of‐the‐art step‐ and graded‐state60Co and pulsed electron irradiation. Results are reported for previously uncharacterized silica fibers containing dopants such as Ge,P,B,F,Tl, and Cs. At short times following the irradiation, fibers which contain Ge exhibit an extremely high attenuation that is not observed when these fibers contain P. Recovery is typically more complete in the silica core fibers than in the doped silica core fibers, which can have losses 25–1000 times the intrinsic loss 3 months after an irradiation of 105–106rad.

ISSN:0003-6951    

DOI:10.1063/1.89862

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The absorption in e‐beam‐pumped Ar/Xe/F2and Ne/Xe/F2mixtures was measured using a flashlamp‐pumped dye laser at 340 nm. The photoabsorption of the active medium affects the extraction efficiency and the length scaling of the laser. The gas mixtures were excited by a 150‐keV 5‐A/cm2beam of fast electrons. The pumping conditions and gas mixtures used were typical of e‐beam‐pumped XeF lasers. Our results confirm that the absorption in Ne‐diluted mixtures is appreciably smaller than in Ar‐diluted mixtures. Data was obtained for a wide variety of mixture pressures and ratios. Using our kinetic model, the results were analyzed and the dominant absorbing species were identified.

ISSN:0003-6951    

DOI:10.1063/1.89871

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The author measured the emission spectrum of the &ngr;3band of SF6at 1780 °K in a shock tube. At this high temperature, the emission peaks at a frequency of 907 cm−1(11.02 &mgr;); at room temperature, the band has a peak intensity at 948 cm−1. Lyman and Nowak observed similar but proportionately smaller shifts of the spectral maximum to lower frequencies at temperatures between 400 and 800 °K. A knowledge of the high‐temperature spectral distribution of the &ngr;3band is important for the design and interpretation of isotope separation experiments in which SF6is dissociated by selective multiphoton absorption of CO2laser photons.

ISSN:0003-6951    

DOI:10.1063/1.89872

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Excitation of atomic krypton in the presence of molecular fluorine by a wavelength‐selective 2.5‐ns‐long argon excimer photolytic source was used to initiate the reaction sequence resulting in the formation of excited KrF. The radiative lifetime of the KrF* laser transition was found to be 9 ns at the high‐pressure limit. This is in good agreement with the calculated values. The rate constant for two‐body quenching of KrF* by F2is 5.7±0.5×10−10cm3 s−1and the rate constant for three‐body quenching by Kr is 2.9±0.3×10−31cm3 s−1.

ISSN:0003-6951    

DOI:10.1063/1.89873

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A large‐volume (6‐liter) electron‐beam‐controlled discharge of about 1 &mgr;sec duration in a Xe/Ar mixture with HCl as the chlorine donor has been utilized to achieve efficient XeCl laser generation at 3080 A˚. At a fixed gas pressure and e‐beam current, the laser output is found to increase rapidly with the initial sustainer field strength up to the spontaneous breakdown limit. Near such a limit, a factor‐of‐25 enhancement of the XeCl laser output energy over that due to e‐beam pumping alone has been observed at 1 atm total pressure. The specific output pulse energy density and laser efficiency based on total energy deposition, of 0.5 J/liter atm and 0.7%, respectively, are beginning to approach the best values reported in the literature for the XeF and KrF lasers.

ISSN:0003-6951    

DOI:10.1063/1.89874

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Superfluorescent FIR lasers near 50 &mgr;m in Rb vapor have been tuned over 800 MHz by using the dynamic Stark effect induced by aQ‐switched CO2laser beam. The latter is nearly resonant with a transition involving the lower level of the FIR laser. A tuning range of several cm−1should be possible by using a TEA CO2laser.

ISSN:0003-6951    

DOI:10.1063/1.89875

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

It is proposed that real‐time holography can be performed inside multimode fibers (or optical waveguides) using four‐wave optical mixing. Of particular interest is the generation of complex‐conjugate replicas of input fields for image transmission and compensation of propagation distortion. A theoretical analysis and a numerical estimate are presented.

ISSN:0003-6951    

DOI:10.1063/1.89876

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Plasma was generated by focusing a 1.06‐&mgr;m 35‐psec laser pulse obliquely onto a solid surface at the optimum resonance absorption angle. The scaling of nonthermal ion emission energy with laser intensity was determined. A computer model for resonance absorption showed nonthermal ion emission to be due to electron acceleration by a resonantly driven electrostatic field.

ISSN:0003-6951    

DOI:10.1063/1.89877

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Photoacoustic spectroscopy is used to obtain dichroism spectra of strongly absorbing samples. The effects, natural or magnetically induced, are recorded with a scale directly comparable to that of the absorption data. The validity of the experiments has been examined using conventional dichroism and absorption techniques on a thin slice of a NdMoO4crystal.

ISSN:0003-6951    

DOI:10.1063/1.89878

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Experimental data collected from a N2O/N2(air) thermally excited and selectively pumped cw gasdynamic mixing laser are reported for a range of low stagnation temperatures and compared with data from a CO2/N2(air) laser. Lasers operating with air yield practically identical output as with usual nitrogen pumping.

ISSN:0003-6951    

DOI:10.1063/1.89879

出版商:AIP    

年代:1978

数据来源: AIP