摘要:

Transmission electron microscopic observations have been made on 100‐keV phosphorus‐implanted silicon layers with a dose of 5 × 1014/cm2as a function of implantation temperature and the subsequent annealing treatment. The annealing behavior of secondary defects is strongly dependent upon the implantation temperature. Also, the nature of dislocation loops formed in the implanted layers shows implantation temperature dependence: dislocation loops in room‐temperature implanted layers are predominantly interstitial in nature, whereas in layers implanted at higher temperatures than 500 °C they are predominantly of vacancy type, and both types of loops coexist in 200–400 °C implanted samples.

ISSN:0003-6951    

DOI:10.1063/1.1654779

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

By studying the morphology of threshold damage and observing for the first time the predicted ``pulse duration‐inclusion size'' relationship, it is shown that the threshold for laser damage to nonabsorbing dielectric coatings is determined by the presence of metallic or highly absorbing nonmetallic inclusions.

ISSN:0003-6951    

DOI:10.1063/1.1654780

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Q‐switched laser‐induced damage to transparent surfaces is shown to occur in many cases without the formation of a bright plasma. This ``aplasmic'' damage is apparently due to absorption by submicron inclusions. The prominence of damage is a function of material, polishing compound, and geometry of the test situation. Because aplasmic damage can be difficult to detect, it is suggested that the results of experiments conducted with small beams, especially when plasma formation is used as a definition of damage, be interpreted with caution. Damage thresholds of several materials are reported incidentally.

ISSN:0003-6951    

DOI:10.1063/1.1654781

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

It is shown by computer calculation that linear dispersion and self‐phase modulation can strongly couple to influence pulse propagation phenomena. Pulses become distorted temporally as they propagate, and, under certain circumstances, optical shocks can form on the leading edge (in time) of a pulse. Some interesting cases are considered for pulse propagation in CS2. The pulse compression scheme of Fisher, Kelley, and Gustafson is modified to take self‐dispersive effects into consideration.

ISSN:0003-6951    

DOI:10.1063/1.1654782

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Defect levels introduced by implanting GaAs with high‐energy protons give rise to optical absorption at wavelengths greater than that of the normal absorption edge at 0.9 &mgr;. Optical waveguide detectors may be fabricated by taking advantage of this absorption mechanism in the presence of a Schottky barrier depletion layer. Detector response times less than 200 ns and external quantum efficiencies of 16% have been observed.

ISSN:0003-6951    

DOI:10.1063/1.1654783

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Electrical studies of W/n‐GaAs Schottky diodes have shown that aging at 350 or 500 °C does not significantly change the forwardI‐Vcharacteristics of the diodes. Using4He+backscattering analysis, it is shown that the W/GaAs interface of simulated diodes does not exhibit any evidence of interdiffusion or reaction. By contrast, considerable alloying occurs in both Au/GaAs and Pt/GaAs systems. In the former, Ga outdiffuses to the surface of Au and Au diffuses into GaAs upon aging at 250 or 350 °C; this has the effect of decreasing the barrier height &phgr;Bfrom 0.9 to [inverted lazy s] 0.6 V and increasing the ideality parameternfrom 1.0 to [inverted lazy s] 1.2. Interdiffusion in the Pt/GaAs couples, aged at 500 °C, results in the formation of a layered arrangement of type PtGa/PtAs2/GaAs. The PtAs2/n‐GaAs interface is associated with a slightly higher &phgr;B([inverted lazy s] 0.89 V) than that found for the Pt/n‐GaAs interface (&phgr;B[inverted lazy s] 0.84 V).

ISSN:0003-6951    

DOI:10.1063/1.1654784

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

We report the use of a dual‐frequency dye laser system to generate continuously tunable far‐infrared radiation over the frequency range from 20 to 190 cm−1. We have investigated both collinear (forward and backward) and noncollinear phase matching in LiNbO3over most of this frequency range and forward collinear phase matching in ZnO, ZnS, CdS, and CdSe at selected frequencies.

ISSN:0003-6951    

DOI:10.1063/1.1654785

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Laser action at 172.9 nm has been observed in xenon and krypton‐xenon mixtures following short‐pulse excitation (2.5 nsec) by a relativistic electron beam. Peak powers [inverted lazy s] 80 kW cm−2in a 5‐nsec pulse were obtained. The pumping sheme used in this work is noteworthy because its high efficiency has made it possible to utilize a simple compact electron accelerator (total electron beam energy 6 J) for excitation. The present short‐pulse data suggest that the rapid decrease in energy efficiency of this laser at high xenon pressures may be due to excited‐state quenching by ground‐state xenon atoms.

ISSN:0003-6951    

DOI:10.1063/1.1654786

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The velocity‐selective characteristic of the interaction between a monochromatic radiation field and a Doppler‐broadened molecular transition is utilized to obtain a narrow saturation resonance for molecules with a given velocity component along the propagation direction of the radiation field. The width of the observed resonance gives the dependence of collision broadening on molecular velocity. The effect is observed in an infrared transition in NH3for self‐broadening and foreign gas broadening by Xe.

ISSN:0003-6951    

DOI:10.1063/1.1654787

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Noncollinear mixing of radiation from CO2TEA lasers has been used to generate phase‐matched far‐infrared difference‐frequency radiation in GaAs. The wavelength of the far‐infrared radiation was tuned from [inverted lazy s] 70 &mgr;m to 2 mm in small steps by selecting the frequencies of the two CO2lasers by means of intracavity diffraction gratings. A theoretical analysis of the two‐dimensional phase matching is presented.

ISSN:0003-6951    

DOI:10.1063/1.1654788

出版商:AIP    

年代:1973

数据来源: AIP