摘要:

On the basis of polarization arguments, the equality &tgr;d=&tgr;lis proposed as the critical condition for the threshold point of chalcogenide glass switches, &tgr;dbeing the dielectric relaxation time and &tgr;lthe carrier lifetime. It is shown that this switching criterion is in good agreement with measurements and that it explains the temperature dependence of the threshold voltage as well as the voltage dependence of the delay time.

ISSN:0003-6951    

DOI:10.1063/1.1654620

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

We report the operation of an experimental model of the Josephson junction shift register known as the flux shuttle.

ISSN:0003-6951    

DOI:10.1063/1.1654621

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A compensation bridge for measuring Voigt magnetoabsorption is set up forXband. Phase and amplitude measurements as a function of magnetic field are done on twon‐type Ge crystals, having resistivities of 11. 9 and 4. 1 &OHgr; cm at 89°K. The magnetic field is applied perpendicular to the direction of propagation and parallel to the microwave electric field (longitudinal case). Theoretical calculations are done by taking into account the mixed scatterings of lattice and impurities. The estimated values of the mobilities due to lattice scattering and impurity scattering are also presented.

ISSN:0003-6951    

DOI:10.1063/1.1654622

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Theoretical studies are presented which show that it should be possible to determine whether the absorption at 10. 6 &mgr;m in alkali halides is due to impurities or whether it is intrinsic. These studies show that the temperature dependence of the measured absorption should be very different for intrinsic multiphonon absorption as compared with defect‐activated absorption.

ISSN:0003-6951    

DOI:10.1063/1.1654623

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The use of ion implantation damage to getter deleterious impurities from diode space‐charge regions is studied. Ion implantation into the neutral regions nearp‐njunctions is shown to cause substantial reduction in the incidence of the type of white video defects (excessive‐leakage current diodes) caused by impurity precipitation and often found in a cyclonic pattern. It is found that using doses of 1016cm−2phosphorus (50 keV), ≥1015cm−2arsenic (150 keV), and ≥3×1015cm−2argon (50 keV) can completely eliminate these defects. In addition, the dark currents of the targets which receive ion implantation is equivalent to or lower than control slices receiving regular phosphorus gettering. From curves of the dark current vs target voltage, it is estimated that the surface recombination velocity (S0) of the ion‐implanted slices is ∼20&percent; lower thanS0in the control slices, while the Si&sngbnd;SiO2interface fixed‐charge density is not affected by ion implantation. By comparing the gettering efficiency of P+‐, As+‐, and Ar+‐implanted slices, it is concluded that the damage layer rather than the presence of an implantedn+region is responsible for the observed gettering behavior.

ISSN:0003-6951    

DOI:10.1063/1.1654624

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Beam steering of a 10. 6‐&mgr;m guided‐wave mode in an electro‐optic GaAs thin‐film waveguide is observed. The deflection angle increases linearly with increasing voltage and interaction length. A switching time of about 60 nsec has been obtained and is limited by the detector response. This technique has been used to obtain more than 12&percent; amplitude modulation of a CO2laser by applying only 50 V to an ∼20‐&mgr;m‐thick GaAs thin‐film waveguide having a total interaction length of 0. 5 cm.

ISSN:0003-6951    

DOI:10.1063/1.1654625

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Experiments have been carried out to study the ionization buildup and gas breakdown processes in the focal volume of an intense 10. 6‐&mgr; laser pulse in atmospheric‐pressure helium preionized to various levels of electron density. With no preionization the laser flux required for breakdown was in agreement with results obtained by previous authors, and showed the same dependence on the focal volume size. However, with a high initial electron density, the threshold was much lower and showed no volume dependence. The results indicate that with preionization the breakdown threshold is controlled by cascade ionization processes, while with no preionization it is dominated by other effects such as small impurity particles in the gas, and that these other effects may be responsible for the diameter dependence of the breakdown threshold.

ISSN:0003-6951    

DOI:10.1063/1.1654626

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Mode control experiments were performed with an unstable TEA repetitive pulsed CO2laser oscillator. Near‐ and far‐field intensity distributions were obtained that are consistent with theoretical values for a diffraction‐limited beam. Performance of the same laser with a stable optical cavity is also given as a reference.

ISSN:0003-6951    

DOI:10.1063/1.1654627

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Electromagnetic radiation of 337‐&mgr;m wavelength has been guided in the form of TM surface waves along thin copper sheets perforated in a regular pattern (metal mesh). Polyethylene prism couplers served for launching and output coupling. The frequency dispersion of the metal mesh guide is similar to that of a transmission line loaded periodically with shunt capacitances. Strong directional dispersion is observed.

ISSN:0003-6951    

DOI:10.1063/1.1654628

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A measurement of the (predominantly) vibration‐vibration (V‐V) decay rate of thev= 3 level in HF gas yields a value of 1.6×106sec−1Torr−1. The technique utilized was to optically pump the HF sample with the output of a pulsed HF laser oscillating simultaneously on a line in both thev= 2 → 1 andv= 1 → 0 bands. An analytic description of the time behavior of thev= 1,v= 2, andv= 3 levels using a treatment based on simplified rate equations is described.

ISSN:0003-6951    

DOI:10.1063/1.1654629

出版商:AIP    

年代:1973

数据来源: AIP