摘要:

Pulsed high‐pressure photostabilized glow discharges can be used to pump ultraviolet lasers on nanosecond time scales. This capability is demonstrated by efficient glow excitation of ultraviolet lasing action in molecular nitrogen. The glow can be generated by simultaneously initiating many electron avalanches over the cathode surface. This glow mode of operation was achieved using a transverse double‐discharge excitation principle.

ISSN:0003-6951    

DOI:10.1063/1.1655348

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Energy and spectral measurements of pulsed discharge‐initiated HF chemical lasers are presented. SF6/H2, SF6/CH4, and SF6/C4H10mixtures at 228, 296, and 373 °K are considered. At the optimum pressure for each mixture, HF chemical laser output has been found to depend weakly on temperature; optimum output energy was enhanced as the initial mixture temperature was decreased. A qualitative explanation for this behavior is offered. The peak power distribution of the HF laser lines at 228 and 296 °K is also discussed.

ISSN:0003-6951    

DOI:10.1063/1.1655349

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Chromatic aberration of the light‐focusing plastic rod (LFR) prepared by the two‐step copolymerization technique of aM1‐M2monomer pair is discussed theoretically. It is found that the chromatic aberration depends on the respective optical properties of theM1polymer andM2polymer alone, and that the selection of aM1‐M2monomer pair is the most important determinant for low chromatic aberration. The requisites for low chromatic aberration are shown. Furthermore, we prepared a LFR with low chromatic aberration by using diethylene glycol bis (allyl carbonate) asM1and 1,1,3‐trihydroperfluoropropyl methacrylate or 1,1,5‐trihydroperfluoropentyl methacrylate asM2; the chromatic aberration parameter is in good agreement with the theoretical value.

ISSN:0003-6951    

DOI:10.1063/1.1655350

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A technique of generating 1‐ns pulses of CO2laser radiation using a CdTe electro‐optic gate driven by a laser‐triggered Blumlein structure is described. By the use of intercavity absorbers, simultaneous output is obtained on multiple rotational lines of both the 9.4‐ and 10.4‐&mgr;m vibrational bands.

ISSN:0003-6951    

DOI:10.1063/1.1655351

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The maximum theoretical solar conversion efficiency is calculated for an organic photovoltaic energy conversion system based on PVK‐TNF. Charge separation is assumed to take place at a Schottky barrier. At high fields (108V m−1) the theoretical energy conversion efficiency approaches a maximum value of 2% with a 2‐eV barrier. Lower efficiencies are found for barriers greater than or lower than 2.0 eV and at lower fields.

ISSN:0003-6951    

DOI:10.1063/1.1655352

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Analyses of ideal models, where heat flow is restricted to one direction, result in good qualitative agreement with the current‐voltage characteristics observed in materials that exhibit an abrupt change in electrical conductivity at a critical temperature, such as VO2. Stability criteria are proved for thermally induced ``S and N‐shaped'' characteristics in two different geometries, where the internal current or field distributions are nonuniform.

ISSN:0003-6951    

DOI:10.1063/1.1655353

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Si planar diodes were obtained with a steep and deep junction except for the lateral edges. This structure was made by a single diffusion of Ga through an opening of the SiO2&sngbnd;Si3N4mask. New planar diodes with unique guard rings have exhibited uniform avalanche multiplication in the broad areas, overcoming the edge breakdown. These devices are shown to be useful as avalanche photodiodes.

ISSN:0003-6951    

DOI:10.1063/1.1655354

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Schottky barrier avalanche photodiodes have been fabricated onn‐type high‐purity epitaxial GaAs. These devices have their largest response at wavelengths beyond the usual absorption edge for high‐purity materials. The absorption mechanism involves the Franz‐Keldysh shift of the absorption edge, and the higher response at the longer wavelengths can be explained by a much higher ionization coefficient for holes than for electrons. The results indicate that the ratio of &bgr;pto &agr;nis even larger than previous measurements have given.

ISSN:0003-6951    

DOI:10.1063/1.1655355

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The Monte Carlo simulation is applied to the study of the diffusion phenomenon of hot electrons inn‐type GaAs. The model simulated is that the ensemble of electrons diffuses from the cathode toward the anode under the two‐valley semiconductor model, repeating the accelerations by the electric field and the collisions to the phonons. This electronic diffusion includes the electron transfer diffusion between valleys as well as the thermal diffusion in each valley. The electric field dependence of the electronic diffusion coefficient determined from the present new approach almost agrees with the Ruch‐Kino experimental result.

ISSN:0003-6951    

DOI:10.1063/1.1655356

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The technique of using thin insulating layers as blocking contacts has been applied to CdS crystals for &ggr; spectroscopy. Detector operation at temperatures up to 100 °C was possible with an energy resolution of 8 keV at 122 keV for a 125‐&mgr;m‐thick crystal. During counting no external bias has been applied: Internal fields of the order of 105V cm−1can be generated if the insulator‐semiconductor interfaces are charged by illumination under external bias. By comparison of the amounts of charge generated by single &ggr; quanta in a germanium crystal and in a CdS crystal, the mean energy to create a pair has been determined to 6.3 eV for CdS.

ISSN:0003-6951    

DOI:10.1063/1.1655357

出版商:AIP    

年代:1974

数据来源: AIP