摘要:

The phase of either near‐field or far‐field distribution function of laser diode arrays can be measured by using the technique of shearing interferometry. Two generations of shearing interferometers are described and typical results using them are shown. For one gain‐guided laser array the phase of the near‐field distribution is shown to be a periodic function whose period is twice the distance between stripes. An example of phase measurement of the far‐field distribution is shown.

ISSN:0003-6951    

DOI:10.1063/1.97609

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A miniature coax circuit incorporating a sensitive InGaAsp‐i‐nand a picosecond photoconductor is described. This circuit is capable of detecting 0.1 fJ infrared pulses with a time resolution of 12 ps.

ISSN:0003-6951    

DOI:10.1063/1.97610

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

This letter describes a new nondestructive measurement technique—cw electro‐optic probing, and reports results of experiments on GaAs coplanar waveguide sample. The technique is simple in instrumentation and convenient in applications. We believe that it can become a powerful tool for studying the electric field in various devices and integrated circuits.

ISSN:0003-6951    

DOI:10.1063/1.97636

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Selective, efficient excitation of TE0nonlinear guided waves is demonstrated numerically. For a thin film bounded by two self‐focusing media, three different field distributions corresponding to the same flux level can be excited independently by suitable Gaussian input beams.

ISSN:0003-6951    

DOI:10.1063/1.97134

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The first direct picosecond time‐resolved measurement of the nonradiative transition dynamics between the excited4T2pump band and the metastable2Estorage level of the trivalent chromium ion in alexandrite is reported. The nonradiative relaxation times of 17 ps for intra‐4T2vibrational transitions, and 27 ps for4T2→2Eelectronic transition are obtained. The thermal repopulation rate of the4T2state from the metastable2Elevel is of the order 3.5×109s−1.

ISSN:0003-6951    

DOI:10.1063/1.97135

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A phase‐locked array of several unstable resonator semiconductor lasers is demonstrated. Single lateral mode was obtained for currentsI<2.5Ith, and partial spatial coherence forI≤5Ith, with an optical output power of 0.95 W.

ISSN:0003-6951    

DOI:10.1063/1.97108

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Cylindrical imploding shock waves were produced by detonating cylindrical explosive shells. TheZ‐pinch discharge was applied to the additive compression of imploding plasmas. Pulsive electric current was supplied through the axis of imploding plasmas at the instant of focusing. An additional rise of temperature of 50–100% was achieved. It might then be concluded that the additive compression of imploding shock plasmas is attained by the application of theZ‐pinch discharge.

ISSN:0003-6951    

DOI:10.1063/1.97109

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A new technique is shown to studyinsituthe chemical composition of sputtered films. The method is based on the x‐ray emission induced by the fast electrons of the sputtering discharge. The sputtering chamber is coupled with a vacuum x‐ray spectrometer. As a demonstration of the method, the Co deposition is studied. The Co L&agr;x‐ray line and the deposition rate (by means of a quartz microbalance) are recorded as a function of time. X‐ray intensity increases quickly during the first minutes of the deposition, then levels off gradually while the deposition rate remains constant. It is speculated that a fraction of a monolayer should be detectable.

ISSN:0003-6951    

DOI:10.1063/1.97110

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Both nitrogen implantation (2.5×1017N+2/cm2at 180 keV) and low‐temperature (≊315 °C) oxidation are shown to produce an order of magnitude reduction in the wear rate of an SAE 3135 steel. Measurements of the wear rates, wear member asymmetry behavior, and both scanning electron microscopy and Auger studies indicate that the same mechanism leads to the much improved wear rates. Both treatments substantiate the initiator/sustainer wear model, in which the initiation treatment reduces the wear to a low value that is sustained throughout the wear test. The sustained stage is a form of mild wear, which involves oxygen and appears to be oxidative wear.

ISSN:0003-6951    

DOI:10.1063/1.97111

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Electrical properties of non‐doped and nitrogen‐dopedn‐type &bgr;‐SiC films grown on Si substrates have been investigated at 70–1000 K. Those of non‐doped films remarkably depend on the Si/C ratio of the source gases. The highest mobilities of non‐doped films are 510 and 1330 cm2 V−1 s−1at 296 and 71 K, respectively. The carrier concentrations are as low as 6×1016cm−3even at 1000 K. Ionization energies of 34 –37 meV for nitrogen donors and 19–25 meV for unknown donors of non‐doped films are obtained. Mobilities of both non‐doped and nitrogen‐doped films are dominated by lattice scattering at high temperatures and by impurity scattering at low temperatures. Nitrogen donors strongly affect the impurity scattering.

ISSN:0003-6951    

DOI:10.1063/1.97112

出版商:AIP    

年代:1986

数据来源: AIP