摘要:

The scattering of a surface acoustic wave reaching a metallized surface region of a piezoelectric crystal is investigated by a numerical finite‐difference method. The perturbation of the electric potential in the discontinuity neighborhood is shown, and the surface wave reflection is determined.

ISSN:0003-6951    

DOI:10.1063/1.88659

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

An acoustic‐surface‐wave resonator using a single periodic grating is described. A 633‐line grating was obtained by ion implantation in quartz (Y,X) with a reflection coefficient larger than 99% at about 125 MHz. An interdigital transducer deposited in the middle of this grating was found to have an input impedance that depended upon the acoustic characteristics of the array. A peak impedance was obtained as a result of the buildup of resonance in the grating and was used to stabilize the frequency of the conventionalL‐Coscillator. In this case, the temperature stability of the oscillator is equal to that of the quartz substrate, that is, 22×10−6/deg.

ISSN:0003-6951    

DOI:10.1063/1.88660

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

TEm‐TMnmode conversion by electro‐optic and acousto‐optic effects in a metal‐diffused optical waveguide is described theoretically. Elastic surface waves and laser beams propagate along theXaxis onY‐cut LiNbO3single crystals, i.e., interactions are collinear. We predict completely the TE1‐TM1mode conversion at an elastic surface wave power of 33 mW along an interaction length of 5 mm with a width of 1 mm.

ISSN:0003-6951    

DOI:10.1063/1.88661

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

We have irradiated slant‐angle‐deposited metallic films on sapphire substrates with pulses of incoherent phonons and observed voltages in the plane of the sample. These voltages are very similar in character to those previously observed using laser irradiation as the excitation source. The new data prove unequivocally that these as well as our previously observed voltages in metal films are purely thermal in origin, consistent with a thermoelectric model.

ISSN:0003-6951    

DOI:10.1063/1.88662

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Vacuum ultraviolet (VUV) photolysis of N2O immersed in high‐pressure Ar has been used to produce O(1S0) at high density. A two‐chamber apparatus was used to prevent the effects of electron and ion collision in the experimental volume, thereby providing a much clearer kinetic situation. The gain profile and stimulated emission cross section near 558 nm and the upper‐state lifetime were determined for ArO.

ISSN:0003-6951    

DOI:10.1063/1.88647

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

A simple reliable transversely excited atmospheric (TEA) laser operating with moderate repetition rates at 337 nm using commercial‐grade N2at 1 atm is described. Preliminary results for a range of operating voltages and channel spacings are presented. The laser’s pulse width is about 1 nsec. Best electrical efficiency to date is 0.039% at 8.8 kV. At 21 kV, 355 &mgr;J/pulse is obtained. Above 16.7 kV, the unfocused output will pump a dye solution to superradiance at a distance of 1.5 m. For supply voltages less than 10 kV, a novel configuration for preionization is described.

ISSN:0003-6951    

DOI:10.1063/1.88648

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Stimulated emission has been produced in mixtures of He, NF3, and Xe at total pressures between 300 and 1000 Torr. Laser emission was on lines at 3511 and 3531 A˚ which have been associated with the excited XeF molecule. Excitation of the gas mixture was by a transverse electric discharge which produced pulses with peak currents of approximately 104A and rise times of 20 ns. A maximum laser energy of 7 mJ was obtained from a gas mixture with a ratio of He:Xe:NF3of 98.0:1.5:0.5 at a total pressure of 300 Torr.

ISSN:0003-6951    

DOI:10.1063/1.88649

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Modal phase dispersion limits image transmission in optical fibers to distances too short to be of general interest. A technique based on nonlinear optical mixing is described for modal phase equalization and recovery of a transmitted image.

ISSN:0003-6951    

DOI:10.1063/1.88650

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Single‐crystal Hg0.77Cd0.23Te has been employed in a spin‐flip Raman laser to generate first Stokes and anti‐Stokes radiation when pumped at 10.60 &mgr;m, and first Stokes, second Stokes, and anti‐Stokes radiation when pumped at 10.28 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.88651

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Spectral power density from Cerenkov radiation was measured in the vacuum ultraviolet from 2000 to 620 A˚. The radiation was produced by passing a 500‐MeV 1‐mA‐peak‐current electron beam through 1.4 m of 1 atm of helium gas at room temperature. In the photon energy range from 6 to 20 eV, approximately 1014photons /sec/A˚/mA of electron‐beam current were emitted, and our detection apparatus attenuated the radiation by 4–5 orders of magnitude.

ISSN:0003-6951    

DOI:10.1063/1.88652

出版商:AIP    

年代:1976

数据来源: AIP