摘要:

The current mean field strength characteristics are calculated for a special model of an insulator in which low‐mobility holes are thermionically emitted from the anode and high‐mobility electrons are cold emitted from the cathode. In the general case, the conduction characteristics are both thickness and temperature dependent.

ISSN:0021-8979    

DOI:10.1063/1.1662171

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A rate equation formulation describing the performance of end‐pumped miniature Nd:YAlG lasers is presented. Expressions for the threshold pump power and laser power output above threshold are given. A numerical example is given and a comparison is made to a previously reported measured threshold power.

ISSN:0021-8979    

DOI:10.1063/1.1662172

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

At the present time the most efficient insulating crystal laser is &agr;‐YAG (Ho3+in sensitized YAG), but the 2.1‐&mgr; cw output from many &agr;‐YAG crystals undergoes a degradation under continuous tungsten lamp illumination. With the aid of a series of liquid optical filters, it is shown that degradation is caused by high‐energy pump photons. At least three different types of degradation are produced depending on the wavelength of pump radiation, but all may be eliminated with a liquid filter that absorbs radiation below 5000 Å.

ISSN:0021-8979    

DOI:10.1063/1.1662173

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A high‐energy pulsed electron beam has been used to dissociate fluorine molecules in fluorine, helium, CO2, and hydrogen chloride gaseous mixtures. By using a probe HF laser and monitoring the amount of ir absorption by hydrogen fluoride resulting from the rapid F + HCl → HF + Cl reaction in these mixtures, the fluorine atom concentration was determined. It was found that an upper limit of approximately three fluorine atoms is produced from each electron‐molecule ionizing collision.

ISSN:0021-8979    

DOI:10.1063/1.1662174

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The light diffracted from transient holographic phase gratings has been used to investigate free‐carrier and thermal effects in ZnO. The gratings were optically induced by two‐photon absorption of two interfering optical beams. A sequential appearance of two gratings was observed: one from free carriers and the other from lattice heating. Diffraction efficiencies varied with the fourth power of the intensity of the interfering beams and reached ≈ 10% at the highest intensities.

ISSN:0021-8979    

DOI:10.1063/1.1662175

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Optical‐coupling efficiencies of slurry‐diced GaP : N green‐light‐emitting electroluminescent diodes have been measured. Light losses due to absorption in such structures are complicated by the irregular diode geometry, the large refractive index, and the significant energy‐dependent optical absorption present in the green spectral region. We show that the optical‐coupling efficiency can be represented as a product of the red‐emission random‐path optical‐coupling efficiency and a ratio of the integrated external spectrum to the integrated internal spectrum. Optical‐coupling efficiencies of encapsulated green diodes in the range 25 ± 5% have been obtained from the measurements, i.e., three times more light is internally absorbed than is usefully transmitted to the ambient. Unencapsulated diodes have about one‐half of this optical‐coupling efficiency.

ISSN:0021-8979    

DOI:10.1063/1.1662176

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Measurements of space‐charge‐limited currents have been performed on CdSe single crystals between 77 and 400 °K. Four groups of electron trapping levels have been found at 0.64, 0.49, 0.35, and 0.167 eV, with densities ranging from 5 × 1010to 1013cm−3. A check of the results with photocurrent vs light intensity and thermally stimulated currents measurements is presented. The origin and the nature of these centers is discussed and correlated with mobility values measured in the crystals investigated. Finally, contacts and geometry considerations are reported.

ISSN:0021-8979    

DOI:10.1063/1.1662177

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Far‐field emission patterns of GaAs&sngbnd;AlxGa1‐xAs double‐heterostructure lasers have been measured to determine the dependence of the beam divergence as a function of active layer thicknessdand compositionx. The beam divergence in the plane of the junction &thgr;∥is ∼ 10°, while the beam divergence perpendicular to the junction plane&thgr;⊥is considerably larger and depends strongly ondandx. Curves are given for&thgr;⊥and the confinement factor &Ggr; as a function ofdbetween 0.05 and 2.0 &mgr; forx= 0.1, 0.2, 0.3, and 0.4. These curves were calculated by considering the laser as a dielectric waveguide with a refractive index step between GaAs and AlxGa1−xAs.

ISSN:0021-8979    

DOI:10.1063/1.1662178

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The processing of integrated circuits usually introduces mechanical stress into the device structure. Contradictory results and speculations exist in the literature on the effects of such stresses on the electrical properties of the SiO2&sngbnd;Si interface. Results of three series of experiments in which the electrical properties were measured by MOS capacitance‐voltage methods are reported. Stress was applied at the SiO2&sngbnd;Si interface by deposition of stressed tungsten films. In the first experiments, the stress at the SiO2&sngbnd;Si interface was varied by deposition techniques and heat treatments. Although several such experiments are reported in the literature, our results demonstrate that such experiments invariably lead to ambiguous results and interpretation. A second series of experiments in which the metallization thickness was varied by planar etching, and a third series in which metallization patterns of widely differing geometries, from 5 to 500 &mgr;m were used, separately show conclusively that mechanical stresses in the range encountered in device structures do not affect the electrical properties of the SiO2&sngbnd;Si interface.

ISSN:0021-8979    

DOI:10.1063/1.1662179

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The photoconductivity in CdS single and polycrystals was investigated by using mode‐locked Nd : glass laser pulses for excitation and was found to exhibit a power lawI2.83±0.2, whereIis the peak excitation intensity. The three‐photon absorption coefficient estimated from the photoconductivity measurement agreed well within an order of magnitude with the theoretical values.

ISSN:0021-8979    

DOI:10.1063/1.1662180

出版商:AIP    

年代:1973

数据来源: AIP