摘要:

Polycrystalline aluminum samples are irradiated with 40‐keV He+. At moderate target temperatures (∼0.3Tm) a prominent and distinct enhancement of the light intensity from sputtered excited aluminum atoms is observed after implantation to a critical dose of 4×1017He+/cm2. It is shown that this effect is associated with a sudden increase in the erosion rate of Al and in the surface exfoliation due to radiation blistering. At higher target temperatures (∼0.7Tm) a less pronounced increase in the photon intensity and a different surface structure is observed.

ISSN:0003-6951    

DOI:10.1063/1.89178

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

High‐speed schlieren photography of the interaction of a TEA CO2laser pulse with the surface of absorbing liquids shows the formation of a complex shock structure in the liquid. The shock structure in liquids with different absorption coefficients at 10.6 &mgr;m is compared. In carbon tetrachloride a cylindrical wave is generated in the bulk of the liquid in addition to the hemispherical wave which is formed at the liquid surface. The cylindrical wave leads the hemispherical one, and this separation is interpreted as differential attenuation in the initial phase. This implies a shock velocity above the sound speed within the first 0.5 &mgr;s.

ISSN:0003-6951    

DOI:10.1063/1.89179

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

A simple physical model is presented to describe some aspects of the sputtering of compound targets. In particular, expressions are developed for the partial sputtering yields for binary systems in terms of the elemental sputtering rates, the stoichiometric concentrations, and surface binding energy. The partial yields depend nonlinearly on the bulk target concentrations. Comparison of the theoretical predictions with the data on sputtering of PtSi, NiSi, and Cu3Au indicates that the general features are well described.

ISSN:0003-6951    

DOI:10.1063/1.89180

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Secondary ion mass spectrometry has been used for depth profiling of arsenic and phosphorus in silicon. High‐sensitivity analysis down to concentrations of a few 1017atoms/cm2could be achieved by energy discrimination against mass interfering molecular secondary ions.

ISSN:0003-6951    

DOI:10.1063/1.89181

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

A new phase‐tuning method for an optical directional coupler fabricated in ac‐plate LiNbO3by TiO2diffusion is presented. The method consists of applying a bias voltage to an additional electrode set closely outside the modulation electrodes. The propagation constants of the two waveguides could be made equal by a bias voltage of 5 V. The modulation voltage of 8 V was unaffected by the bias voltage.

ISSN:0003-6951    

DOI:10.1063/1.89182

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Off‐resonance optical pumping of thesR(5,0) line of the &ngr;2fundamental band of14NH3has yielded over 2.0 kW of superfluorescent emission on thesP(7,0) transition at 12.079 &mgr;m. Emission at 11.460 &mgr;m attributed to theaP(3,1) transition was also observed by pumping theaR(1,1) absorption line with a 1‐MW CO2TEA laser.

ISSN:0003-6951    

DOI:10.1063/1.89183

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

A new preparation method of a light‐focusing plastic rod (LFR) is reported, where the photocopolymerization of methacrylic esters (M1) such as methyl methacrylate (MMA) with vinyl benzoates (M2) such as vinyl benzoate (VB), vinylo‐chlorobenzoate, and vinylo,p‐dichloro‐benzoate was carried out. TheM1‐M2mixture placed in a glass tube was exposed to uv light by rotating a glass tube about its axis. LFR prepared from a MMA‐VB pair has a quadratic gradient constant with a refractive indexA= (3∼11) ×10−3mm−2, an internal loss of light transmission IL= (3∼12) dB/m, and a ratio of the radius of the imaging region to the rod radius (ri/rp) =0.5∼0.7.

ISSN:0003-6951    

DOI:10.1063/1.89184

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Third‐harmonic generation of a ruby laser has been achieved in a potassium pentaborate tetrahydrate (KB5O8⋅4 H2O) crystal through type‐1 frequency mixing of the fundamental and second‐harmonic radiation. An over‐all power conversion efficiency of 0.2% was obtained.

ISSN:0003-6951    

DOI:10.1063/1.89185

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Tunable laser emission in the 335–346‐nm region has been obtained from a 0.01Msolution ofp‐terphenyl inp‐dioxane. The dye laser was excited by a 20‐nsec pulse from a Blumlein‐driven KrF laser oscillating at 249 and 250 nm.

ISSN:0003-6951    

DOI:10.1063/1.89186

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

We have demonstrated that low‐energy electron irradiation of silica glass leads to a sufficient change in the refractive index to form optical waveguides. A peak enhancement of at least 0.9% is achieved by the deposition of some 1024keV cm−3and is stable to at least 200 °C. This energy requirement is consistent with measurements of lattice compaction in silica which also reaches a maximum value when ∼1024keV cm−3is deposited in ionization or electronic excitations. (The change is thought to be the result of irradiation damage). It is noted that changes induced in this way might have application in both integrated optics and graded index fibers.

ISSN:0003-6951    

DOI:10.1063/1.89187

出版商:AIP    

年代:1976

数据来源: AIP