摘要:

A Rollin free‐carrier InSb bolometer has been operated in both video and heterodyne modes at 4 mm wave‐lengths. Responsivities ∼1.75 × 103V/W were obtained at 1.2°K with N.E.P.'s for (a) the video mode ∼10−13W, and (b) the heterodyne mode ∼8 × 10−21W, using an i.f. ∼ 2.6 kHz.

ISSN:0003-6951    

DOI:10.1063/1.1651907

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Recombination radiation from electron‐hole pairs generated by impact ionization has been observed in heavily doped CdTe at electric field intensities higher than those required to produce Gunn oscillations in lightly doped material. The suppression of the Gunn effect in the more heavily doped CdTe is attributed to a decrease in the magnitude of the negative differential mobility displayed by the drift velocity vs electric field characteristic resulting from the presence of ionized impurity scattering.

ISSN:0003-6951    

DOI:10.1063/1.1651908

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Linewidth narrowing attributed to superradiance has been observed in near bandgap radiation due to the recombination of impact ionized carriers inn‐type CdTe at room temperature. The light emission was associated with a current breakdown that occurred at a threshold field of 12,000 V/cm in highly compensatedn‐type samples.

ISSN:0003-6951    

DOI:10.1063/1.1651909

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

The output of pulsed argon ion lasers with an axial magnetic field was studied as a function of magnetic field, current, inside diameter, pressure, and oscillating wavelength. The increased output and efficiency obtained by use of an axial magnetic field clearly indicate its advantages. A simple method of providing the required magnetic field is described.

ISSN:0003-6951    

DOI:10.1063/1.1651910

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

The second‐harmonic, phase‐matching temperature of ``stoichiometric'' LiNbO3crystals, for fundamental radiation at 1.06 &mgr;, has been found to vary by as much as 75°C from crystal to crystal and 10°C within an individual crystal. Measurements on crystals grown in a controlled manner from nonstoichiometric melts have shown that the phase‐matching temperature,T, is an approximately linear function of melt composition,x, obeying the equationT= 50.5 + 32 × 102(x− 0.50). Crystals with phase‐matching temperatures of as high as 186°C have been grown from melts containing excess lithia. Such a crystal has been operated as a second harmonic generator without damage, whereas a comparable radiation produced by a crystal with a low phase‐matching temperature damaged the crystal. A mechanism involving lithium ion vacancies is proposed to explain the results.

ISSN:0003-6951    

DOI:10.1063/1.1651911

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

The Curie temperature, birefringence, and phase‐matching temperature of LiNbO3are shown to vary with the stoichiometry of the melt from which the crystals are pulled. The range of melt stoichiometry, indexed by the Li/Nb mole ratio, was varied from 1.20 to 0.80. This Li/Nb variation changes the Curie temperature, refractive index for the extraordinary ray, and the phase‐matching temperature by 120°C,.03, and 320°C respectively. The relevance of these changes are discussed in terms of the susceptibility of LiNbO3to index inhomogeneities.

ISSN:0003-6951    

DOI:10.1063/1.1651912

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

The experimentally observed distributions of surface state density versus energy is correlated with the existence of coulombic centers in the oxide. Single charges give rise to peaks in surface state density close to the band edges, deeper levels are introduced by two charges in close proximity.

ISSN:0003-6951    

DOI:10.1063/1.1651913

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Measurements of optically excited parametric noise which demonstrate the importance of noncollinear phase matching are presented. The absolute magnitude of the emitted noise has also been measured and is found to be in excellent agreement with theory.

ISSN:0003-6951    

DOI:10.1063/1.1651914

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

An electron field emitter is used as an approximate point source of electrons to produce magnified shadows, or profile images, of small electrically conducting objects in ultrahigh vacuum. Some electrical and electron optical properties of this type of microscopy are described.

ISSN:0003-6951    

DOI:10.1063/1.1651891

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Superradiant, stimulated emission at 3371 Å has been observed from spark discharges in air at atmospheric pressure. This emission corresponds to transitions in the second positive band system of molecular nitrogen. Duration of the emitted laser pulse is about 0.6 nsec and peak power output is about 2 W.

ISSN:0003-6951    

DOI:10.1063/1.1651892

出版商:AIP    

年代:1968

数据来源: AIP