摘要:

In a ring cavity the counter‐propagating modes are coupled through a homogeneously broadened atomic medium. The mode coupling is shown to introduce novel features in the transmission characteristics of two simultaneous bistable switches. We suggest suitable materials and discuss possible applications of the predicted effect.

ISSN:0003-6951    

DOI:10.1063/1.92431

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We report the first tunable laser action of a platelet semiconductor in an external cavity. We have achieved cw output powers of up to 9 mW from a CdS platelet optically pumped by an Ar+laser at 476 nm. The energy conversion efficiency is 10% into the TEM00mode. Tunability of the laser output was demonstrated from 495 to 501 nm using an intracavity prism with the crystal kept at a temperature of 95 K. Additional tuning to 504 nm was achieved by varying the temperature to 140 K.

ISSN:0003-6951    

DOI:10.1063/1.92432

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We describe a means of eliminating undesired surface guiding in titanium‐diffused strip waveguides on LiNbO3. Surface guiding for light of the extraordinary polarization, normally produced when the crystal is diffused in dry argon or oxygen, can be eliminated entirely by adding water vapor to the diffusion gases. Infrared absorption measurements show that hydrogen enters crystals diffused in a wet atmosphere. Although the mechanism for the prevention of surface guiding is not fully understood, we suggest that the presence of excess hydrogen reduces lithium mobility.

ISSN:0003-6951    

DOI:10.1063/1.92433

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The spectral width of (GaAl)As cw single‐mode diode lasers varied linearly with reciprocal output power at 300 K with a slope 50 times greater than that predicted by the Schawlow‐Townes expression without partial inversion. While the spectral narrowing observed at 77 K for constant mode power is consistent with the predicted temperature dependence of the partial inversion contribution, the magnitude of the broadening can not completely be attributed to partial inversion.

ISSN:0003-6951    

DOI:10.1063/1.92434

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Ultrashort pulse generation has been achieved in a UV‐preionized transverse discharge XeCl laser by injection mode‐locking using the second harmonic of a passively mode‐locked Rh 6G dye laser tuned to the XeCl gain bandwidth. Temporal measurements using a Photochron II streak camera showed pulse durations ∼7 ps with single‐pulse peak power of ∼150 MW.

ISSN:0003-6951    

DOI:10.1063/1.92435

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

To date, imaging and metrology in the acoustic microscope have been performed exclusively on planar specimens. While imaging is accomplished by raster scanning in the planetransverseto the axis of the acoustic beam, metrology is practiced by variation of the specimen‐lens separationalongthe beam axis. This operation yields an acoutic material signature at a single location on the specimen plane. The two modes of operation are in effect simultaneously employed when a nonplanar surface of known curvature is scanned. The resulting images reveal concentric rings with radial periodic brightness variation if the surface is spherical in shape. The technique is demonstrated with stainless‐steel bearing balls of the type used in precision gyros. The application of this technique to the diagnostic inspection and analysis of both bearing balls and raceways are discussed. It is suggested that the obtained images represent a two‐dimensional map of elastic properties of the bearing surface regions.

ISSN:0003-6951    

DOI:10.1063/1.92436

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

For a class of initial conditions, the Cauchy problem is studied for electrostatic fluid equations that describe expansion of a cloud of ions in one dimension. The fluid motion which results is a type of free streaming of charged particles in a self‐consistent electrostatic field. The exact solution obtained in planar geometry is compared with self‐similar solutions and with previous investigations.

ISSN:0003-6951    

DOI:10.1063/1.92420

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Measurements done on a new plasma device, a laser initiated, gas‐embeddedZpinch, are compared with magnetohydro dynamics(MHD) calculations. The measurements, which include two‐foil x‐ray absorption, absolute continuum emission, and schlieren shadowgraphy, are in good agreement with predictions made by a two‐dimensional MHD calculation, which indicates that the peak electron temperature in the plasma is 200 eV and the peak electron density is 1×1020cm−3.

ISSN:0003-6951    

DOI:10.1063/1.92437

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Surface compositional modifications of binary alloys during 15‐keV O+2bombardment under 45° incidence were studied using Auger electron spectroscopy under ultrahigh vacuum conditions. For A1‐Ni, Cr‐Ni, Fe‐Ni, and Pd‐Ni alloys, the reactive preferential sputtering by O+2causes a surface enrichment of the alloy component which has the smaller metal‐oxygen bond energy per metal atom. For Cu‐Ni and Ag‐Pd alloys, where oxidation by the O+2beam was slight, the surface compositions after O+2bombardment were qualitatively similar to those caused by nonreactive preferential sputtering with Ar+.

ISSN:0003-6951    

DOI:10.1063/1.92438

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Al single crystals were implanted with 150‐keV He+ions at room temperature to fluences high enough to produce several layers of exfoliation. Each exfoliated layer occurs by spalling of the entire bombarded crystal surface, and step height measurements show that the spalling occurs at a depth less than the calculated projected range of the He ions. Preliminary evidence from aligned backscattered (channeling) spectra of exfoliated crystals indicates that the He remaining in the crystal after spalling is in the form of bubbles.

ISSN:0003-6951    

DOI:10.1063/1.92439

出版商:AIP    

年代:1981

数据来源: AIP