摘要:

Optical inhomogeneities in arsenic‐doped silicon have been observed at a near‐infrared wavelength of 3.39 &mgr;m with a scanned laser infrared microscope. The inhomogeneous distribution of impurities in the crystal includes segregation striae and a central faceted area. Results are compared with 1.1‐&mgr;m infrared microscopy and x‐ray diffraction topography. An interpretation of Tiller's mechanism for dislocation production is shown to be invalid for the case of arsenic‐doped silicon.

ISSN:0003-6951    

DOI:10.1063/1.1653261

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

We report that the application of an ultrasonic compressional wave to a thin layer of nematic liquid crystals results in optical scattering. This effect, which possesses both threshold and gray‐scale properties, is potentially useful for real‐time ultrasonic visualization for nondestructive testing and medical applications.

ISSN:0003-6951    

DOI:10.1063/1.1653262

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Optical absorption bands characteristic of localized vibrational modes for both interstitial and substitutional oxygen have been observed in crystalline Si implanted with 220‐keV oxygen ions at 300°K. In addition, the fluence dependences for the vibrational modes and also for an electronic transition of the divacancy (1.8‐&mgr; band) have been measured. Implanted oxygen ions are found to enhance divacancy formation. This effect was not observed for Sb implantation. The sum of the observed interstitial and substitutional oxygen centers is approximately equal to the number of implanted oxygen ions. An ion fluence 300 times larger than that to detect divacancies was required to detect the vibrational modes of oxygen as expected from the relative production rates and absorption coefficients. At these high fluences the strengths of the vibrational bands increase in magnitude with fluence while the divacancy band decreases. At even higher fluences amorphous layer formation, as indicated by a milky coloration of the surface, caused a decrease in the spacing of optical interference fringes and in the magnitude of the oxygen vibrational bands.

ISSN:0003-6951    

DOI:10.1063/1.1653263

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

This letter reports laser action in the visible (near 7000 Å) and near infrared on transitions of atomic fluorine. The pumping process is dissociative collisions of helium metastable atoms with hydrogen fluoride. Lower levels of the laser transitions are depopulated by both uv radiative transitions and in collision with ground‐state hydrogen atoms.

ISSN:0003-6951    

DOI:10.1063/1.1653264

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

We report optical second harmonic generation in form of coherent Cerenkov radiation. The fundamental wave at 1.06 &mgr;m propagates in a thin‐film optical waveguide which is simply a ZnS film vacuum‐deposited on a single‐crystal ZnO substrate. The nonlinear polarization excited in the substrate has a phase velocity exceeding that of radiation propagating freely in the substrate material. It thus acts as the source of the observed Cerenkov radiation.

ISSN:0003-6951    

DOI:10.1063/1.1653265

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Properties of thin‐metal‐film bolometer detectors deposited upon high thermal conductivity substrates are described. Measured response time is less than 15 nsec and NEP is found to be less than 10−6W/Hz1/2.

ISSN:0003-6951    

DOI:10.1063/1.1653266

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Particles moving with known constant velocities are used to calibrate a photo‐counting apparatus. Velocities from 1 to about 10−5cm/sec are measured conveniently.

ISSN:0003-6951    

DOI:10.1063/1.1653267

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A method is described to grow successfully from solution AlxGa1−xAs1−y′Py′(p‐type) on GaAs1−yPy(n‐type), to preserve the lattice match (y′≈y), and to obtain the improved heterostructure junction devices previously realized only in the AlGaAs/GaAs system. Although not optimized, these structures have been operated as pulsed room‐temperature lasers, and because of an inherent wide‐gap window can be used conveniently for optical purposes and for excess carrier lifetime measurements. Carrier lifetime measurements, for example, indicate freedom from defects at the AlGaAsP/GaAsP barrier.

ISSN:0003-6951    

DOI:10.1063/1.1653268

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

Presently, silicon device technology phosphorous diffusions with high surface concentrations are commonly used for the formation of the emitter areas. Annealing treatments at or below 800°C have been shown to lead to the formation of extrinsic dislocation loops in such areas. A transmission electron microscopic investigation combined with resistivity measurements and profile determinations leads to the interpretation of these loops as a primary step of phosphorous precipitation in the supersaturated lattice.

ISSN:0003-6951    

DOI:10.1063/1.1653269

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

The complete mutual solid solubility of hexagonal close‐packed forms of erbium and zirconium has been observed by x‐ray diffraction for specimens rapidly quenched from the liquid state to room temperature. The lattice parameter measurements show negative deviations from the linearity as expressed by Vegard's law, with maximum deviations &Dgr;V/Vof ≲ 2% at approximately 41 at. % Zr and 2.3% at 70 at. % Zr. The axial ratioc/aremains as a linear relationship between those of two elements. The formation of the metastable solid solutions can be explained by classical rules.

ISSN:0003-6951    

DOI:10.1063/1.1653270

出版商:AIP    

年代:1970

数据来源: AIP