摘要:

A preliminary study of up‐conversion as an approach to high‐speed detection of 10.6‐&mgr;m laser radiation is reported. Using synchronized Nd : YAG and TEA CO2lasers, conversion to 0.96‐&mgr;m radiation in proustite has permitted the detection of mode‐locked TEA laser pulses with an overall system bandwidth of 900 MHz.

ISSN:0003-6951    

DOI:10.1063/1.1654961

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The nature and origin of the defects responsible for the rapid degradation of stripe geometry GaAs&sngbnd;GaAlAs double‐heterostructure lasers have been identified by transmission electron microscopy. These defects are formed by a three‐dimensional dislocation network which originates at a dislocation crossing the GaAlAs and GaAs epilayers. The propagation of the dislocation network takes place by aclimbmechanism induced by the operation of the device.

ISSN:0003-6951    

DOI:10.1063/1.1654962

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Light‐emitting diodes fabricated from the GaAs1−xPxalloy system undergo degradation upon neutron irradiation. It has been found that the smallest change in efficiency occurs when the composition of the alloy is betweenx= 0.30 andx= 0.75. The change in minority‐carrier lifetime, however, is approximately constant throughout the entire alloy range. It is suggested that the relative insensitivity to neutron irradiation of the efficiency in the alloy rangex= 0.30–0.75 is connected with the inherent disorder already present within the GaAs1−xPxalloy system.

ISSN:0003-6951    

DOI:10.1063/1.1654963

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A new configuration for flash‐pumped dye lasers is presented. A coaxial dye cell with internal excitation is used and 2% efficiency is feasible. Optical cavity deterioration produced by thermally induced refractive index gradients is compensated by the coaxial geometry, and low‐loss guided propagation results without any recirculation of the dye solution.

ISSN:0003-6951    

DOI:10.1063/1.1654964

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A laser Doppler interferometric technique for measuring small absorption coefficients of infrared‐transmitting materials is described. The interferometer is calibrated as a remote temperature sensor by monitoring optical path length changes of the sample as a function of temperature. The sample is then irradiated by a CO2laser and the change in optical path due to absorbed laser energy is observed interferometrically as a function of time. From this measurement and the calibration data, a temperature‐vs‐time curve is generated from which the absorption coefficient of the sample at 10.6 &mgr; may be calculated.

ISSN:0003-6951    

DOI:10.1063/1.1654965

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Niobium‐germanium films which remain superconducting up to 22.3 K have been prepared by a high‐pressure dc sputtering process. The highTc's of these films are attributed to the formation of a more nearly perfect stoichiometric Nb3Ge compound than has previously been obtainable.

ISSN:0003-6951    

DOI:10.1063/1.1654966

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A modified Kerr optical technique was used to view the polar Kerr component at the head‐on domain wall of a magnetic thin film. The observation substantiated the polar magnetic configuration previously proposed and allowed a direct measurement on the width of the domain wall.

ISSN:0003-6951    

DOI:10.1063/1.1654967

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Bubble domains have been observed in five composite garnet structures consisting of two epitaxial magnetic layers separated by a layer of nonmagnetic garnet. The static and ``ordering'' properties of the domains are described and the arrangement of the overlying domains is discussed as a function of bias field. It is shown qualitatively that the strength of the magnetostatic interaction between the two magnetic layers can be changed considerably by varying the relative film thicknesses in the composites.

ISSN:0003-6951    

DOI:10.1063/1.1654968

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Monte Carlo calculations confirm that contrast observed in the scanning electron microscope from magnetic domains in materials of cubic anisotropy is due to the alteration of electron trajectories within the specimen. Results are presented for the effects of electron accelerating potential, specimen tilt, and rotation. The contrast arises mainly from the high‐energy portion of the back‐scattered electron distribution.

ISSN:0003-6951    

DOI:10.1063/1.1654969

出版商:AIP    

年代:1973

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.1654971

出版商:AIP    

年代:1973

数据来源: AIP