摘要:

TE00and TE01optical waveguide modes have been observed in GaAs stripep−njunctions produced by zinc diffusion through SiO2masks inton−type substrates. Excellent agreement was found between guided light profiles at 1.15 &mgr;m and those predicted on the basis of refractive index profiles given by the free−carrier plasma effects.

ISSN:0003-6951    

DOI:10.1063/1.88153

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A passively mode−locked TEA CO2laser has been operated with an unstable resonator, and mode−locked trains with peak powers ≳150 MW, together with near diffraction−limited beams, have been obtained. Single axial mode operation at a power level of 14 MW has also been achieved. These results represent a significant improvement over similarly dimensioned systems using stable resonators.

ISSN:0003-6951    

DOI:10.1063/1.88154

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A weak uv source conditions a CO2laser gas discharge with the aid of the seed gas tri−n−propylamine. Rich mixtures and high input energy densities can be used, resulting in extremely high peak powers.

ISSN:0003-6951    

DOI:10.1063/1.88155

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Growth techniques and passive evaluation of tapered waveguide light couplers produced by LPE and MBE are reported. Coupling efficiencies approaching 100% for the transfer of light from a GaAs layer to a layer of Al0.1Ga0.9As are observed for MBE tapers, and tapers fabricated by LPE allow ∼50% coupling, suitable for use with LPE active devices.

ISSN:0003-6951    

DOI:10.1063/1.88145

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

The Mo¨ssbauer spectrum data of &eegr;−FexGe was determined at room temperature and liquid−nitrogen temperatrue. It was found to be the same for the compositionx=1.23 andx=1.11. X−ray diffraction results are in good agreement with published data.

ISSN:0003-6951    

DOI:10.1063/1.88156

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

The Bitter technique has revealed two kinds of planar domains in the Permalloy overlays associated with bubbles in Permalloy−coated garnet films. Measurements of dynamic properties of bubbles have shown that all the bubbles in these films have either zero or two Bloch lines. In addition, it has been clarified that the number of Bloch lines in the domain walls depends on the kind of planar domains through exchange interaction across the interface between garnet and Permalloy.

ISSN:0003-6951    

DOI:10.1063/1.88157

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

With the standard plane−parallel configuration of semiconductor detectors, good &ggr;−ray spectra can only be obtained when both electrons and holes are completely collected. We show by calculations (and experiments) that with contacts of hemispherical configuration one can obtain &ggr;−ray spectra of adequate resolution and with signal heights of nearly full amplitude even when only one type of carrier is collected. Experiments with CdTe detectors for which the &mgr;&tgr; product for electrons is about 103times that of the holes confirm these calculations. The adoption of hemispherical contacts thus widens the range of high−resistivity semiconductors potentially acceptable for &ggr;−ray detection at room temperature.

ISSN:0003-6951    

DOI:10.1063/1.88158

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

We discuss some problems associated with obtaining an atomic beam with a large fraction of excited−state atoms. We show, e.g., that for sodium atoms to be pumped up into the 32P1/2state, they must experience a minimum of three optical frequencies near theD1line. In order to achieve this with only one optical frequency, the following method is proposed: A strong laser beam impinges three times on an atomic beam, each time under a different angle, in such a way that for one velocity class the Doppler shift generates the three frequencies needed. The effects of the polarization of the laser beams are discussed.

ISSN:0003-6951    

DOI:10.1063/1.88159

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

Images were formed in PbI2layers covered with a polymer film by laser pulses in the nanosecond range. The local vapor pressure of PbI2due to the resulting local heating led to the formation of bubbles which act as scattering centers for transmitted light.

ISSN:0003-6951    

DOI:10.1063/1.88144

出版商:AIP    

年代:1975

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.88251

出版商:AIP    

年代:1975

数据来源: AIP