摘要:

It is shown that an electrostatic field applied to the interaction medium of an acoustically tuned optical filter can shift the center wavelength of the optical passband, without significantly altering the optical bandwidth. For the crystallographic orientation of the LiNbO3medium selected for this experiment, we verify a 2‐A˚ shift in optical passband for each kV cm−1of applied electrostatic field. This effect can be used to overcome limitations in the tuning range and/or electrical efficiency imposed by transducers in the operation of acoustically tuned optical filters. This phenomenon can be particularly useful in optical filters of small dimensions such as those found in integrated optical waveguide structures.

ISSN:0003-6951    

DOI:10.1063/1.89443

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

We show that the chirp rate of an optical pulse emerging from a nonlinear medium may be reversed near its peak if a backward pulse is present simultaneously in the medium. This provides a nonresonant chirp compensation technique.

ISSN:0003-6951    

DOI:10.1063/1.89444

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

The impact transferred from laser‐produced plasma to target was measured, and the formed plasma was studied by schlieren and shadow photographs. The cylindrical detonation wave theory was in general agreement with the plasma features in the early energy deposition phase but failed to predict the momentum transfer from plasma to target. The momentum transfer agreed with the theory of spherical blast wave which follows the cylindrical detonation wave.

ISSN:0003-6951    

DOI:10.1063/1.89445

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Far‐infrared detection using the bulk photoconductivity associated with negative donor ion states in silicon is found to provide nanosecond response times and quantum efficiencies of a few percent. It is estimated that this detector can be used in a heterodyne receiver with NEP’s in the range from 10−16to 10−19W/Hz in the wavelength range from 100 to 500 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.89446

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Focusing of charge‐ and current‐neutralized intense ion beams is accomplished by propagating the beam along a spatially periodic axial magnetic field. This focusing results in local variations in the beam radius and density. At one location, the measured particle density is enhanced over the emitted density by at least a factor of 4. Current density enhancements in excess of an order of magnitude using this method should be obtainable.

ISSN:0003-6951    

DOI:10.1063/1.89447

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

In a microwave experiment simulating laser‐plasma interactions, the production of fast electrons by the parametric decay instability is found to be significantly decreased by replacing a monochromatic pump with a noisy one. With this experimental arrangement, it is observed that finite bandwidth also inhibits the formation of density cavitons.

ISSN:0003-6951    

DOI:10.1063/1.89448

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Measurements have been made of the change in residual electrical resistivity in thin‐film specimens of Cu and Ag induced by light‐ion irradiations (H,D,3He,4He) below 10 K in the energy range 15–40 keV. The number of Frenkel pairs created per incident ion was deduced and compared with theoretical predictions. The efficiency factor (ratio of experimental to theoretical value) was found to decrease from ∼1 to 0.7 (0.9 to 0.65) for Cu (Ag) as the recoil spectrum was shifted to higher energies by increasing the projectile mass and/or energy.

ISSN:0003-6951    

DOI:10.1063/1.89449

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

In this paper we report two‐ and three‐body quenching of the XeF* (B2&Sgr;+1/2) state by Ar and Xe. The rate constants were obtained by analyzing the dependence of (B2&Sgr;+1/2→X2&Sgr;+1/2) radiation on the partial pressures of Ar, Xe, and F2. The XeF* was produced by a high‐energy e‐beam. We have determined the two‐ and three‐body quenching rates by Ar to be 8±4×10−13cm3/sec and 1.5±0.5×10−32cm6/sec. Xe quenches XeF* with a three‐body rate constant of 3±1.5 ×10−31cm6/sec; the third body was mainly argon.

ISSN:0003-6951    

DOI:10.1063/1.89440

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

A high‐power Nd : glass laser beam was focused on freely falling deuterium ice pellets. It was demonstrated that this method allows reliable and reproducible production of an isolated deuterium plasma cloud suitable for filling a plasma machine. The plasma with a total ion number of (1–2) ×1017expands quite uniformly at a velocity of (1–3) ×107cm/s. However, the pellet is not completely ionized, which is in accordance with theoretical predictions. The greater portion of the pellet disintegrates after the laser shot and expands with a velocity of approximately 1×106cm/s.

ISSN:0003-6951    

DOI:10.1063/1.89441

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

The excitation of a fluorophore by rapidly varying fluctuations in a free‐running argon‐ion laser is shown to produce variations in measured fluorescence. The power spectrum of the fluctuations can yield lifetime information on luminescence and the experimental apparatus described exploits this phenomenon. Methods of improving the measurements are also considered.

ISSN:0003-6951    

DOI:10.1063/1.89442

出版商:AIP    

年代:1977

数据来源: AIP