摘要:

The tunneling characteristics of Cr/SiO2/Si structures in the thickness range 23–34 Å are reported. TheE‐&kgr; dependence in the energy range extending 3.5 eV below the oxide conduction band is determined by the thickness dependence to be approximately of the Franz form with an effective mass ratio of 0.42. Tunneling into the indirect conduction band of silicon is reduced by a thickness‐independent factor which decreases approximately exponentially with the energy below the direct band edge.

ISSN:0003-6951    

DOI:10.1063/1.1655275

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Photoemissive yield measurements were performed on degeneraten‐type and semi‐insulating GaN for heat‐cleaned and for cesiated surfaces. The photoemissive threshold for heat‐cleanedn‐type material occurs at 4.1 eV, while that for semi‐insulating material is beyond 5.5 eV, the experimental spectral range. From these measurements an upper and a lower limit of the electron affinity of heat‐cleaned GaN is derived, namely 4.1 > &khgr; > 2.1 eV. The threshold for cesiated surfaces on both materials is lowered to 1.5 eV, and the photoyield curve exhibits a second threshold at about 3.4 eV. The occurrence of negative electron affinity is suggested for cesiated semi‐insulating GaN.

ISSN:0003-6951    

DOI:10.1063/1.1655276

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

NO spectroscopy at temperatures up to 100 °K was achieved with a pulsed PbS0.4Se0.6diode laser. A frequency chirping rate of about 0.3 cm−1/&mgr;s was obtained. The variation of the threshold current density and laser wavelength versus temperature is presented.

ISSN:0003-6951    

DOI:10.1063/1.1655277

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Millimeter radiation obtained by difference‐frequency mixing of theP(20) andP(22) lines of the CO2laser has been used to investigate the polarization, radiation pattern, and bias characteristics of metal‐barrier‐metal point‐contact diodes. The results are consistent with antenna theory and the electron tunneling model of the point contact. Significant enhancement in performance is expected with eventual use as a submillimeter source.

ISSN:0003-6951    

DOI:10.1063/1.1655278

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Time lags for the growth of power input, i.e., formative time lags, have been measured in typical CO2laser gas mixtures at pressures from 200 to 760 Torr using parallel plane electrodes with the 1‐ and 2‐cm gaps illuminated by a trigger discharge. The measured time lags are about twice the values predicted using a single avalanche growth model and theoretical ionization and attachment coefficients.

ISSN:0003-6951    

DOI:10.1063/1.1655279

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The optical deflection efficiency of an acousto‐optic modulator with a lead molybdate interaction medium has been measured at optical wavelengths in the region 442–1152 nm. The crystal orientation was such that the acoustic beam propagated along the optic axis and the optical beam near theaaxis. The dependence of the relative figure of merit on optical wavelength and polarization has thus been determined. The results indicate that the figure of meritM2is independent of the optical polarization at 633 and 1152 nm, but that a considerable and unexpected sensitivity to polarization occurs between 442 and 515 nm.

ISSN:0003-6951    

DOI:10.1063/1.1655280

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The results of experiments performed to check the possibility of stimulated emission in the extreme vacuum ultraviolet (VUV) by an Al+3laser‐generated plasma are reported. It is concluded that the spectral line intensity anomalies previously observed are not due to population inversion.

ISSN:0003-6951    

DOI:10.1063/1.1655281

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Epitaxial layers of GaAs have been successfully grown on corrugated GaAs substrates. Growth techniques were such that the corrugation was preserved during the growth process. Growth conditions are described which permitp‐njunctions containing corrugations of period suitable for electrically pumped distributed‐feedback lasers in GaAs to be produced. This work demonstrates that there are no fundamental limitations on growing buried corrugations in GaAs for a large variety of integrated optical devices.

ISSN:0003-6951    

DOI:10.1063/1.1655282

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The distinction between ``swirls'' and ``striations'' in silicon crystals is reemphasized. The role of swirl‐nucleated stacking faults in introducing excess reverse currents inp‐njunctions is distinguished from the relatively inactive nature of striations with respect to carrier recombination‐generation effects. The suggestion of Yoshikawa and Chikawa of a crystal‐growth‐direction‐dependent electric field at striations has been examined using the electron‐beam‐induced‐current (EBIC) technique. The contrast effects observed at striations using the EBIC technique show no effects of growth‐dependent electric fields.

ISSN:0003-6951    

DOI:10.1063/1.1655283

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The response of a phase‐sensitive detector is examined when its input signal is derived by modulation of a laser‐saturated absorption line shape. Neglecting the laser background power curve, it is shown that second‐harmonic distortion in the modulation gives rise to the largest laser frequency offset, 0.2% of such distortion yielding approximately 4.5 kHz frequency offset. The distortion effects are also examined when the background power curve is included.

ISSN:0003-6951    

DOI:10.1063/1.1655285

出版商:AIP    

年代:1974

数据来源: AIP