摘要:

A method of measuring sound velocities in crystals using Bragg diffraction of light by ultrasonic waves is described. Sound‐velocity data presented for LaF3are consistent with a trigonal crystal structure and exclude the possibility of a hexagonal structure.

ISSN:0003-6951    

DOI:10.1063/1.1652626

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Radiation resistance measurements have been made on 20 electrode pair interdigital transducers deposited on poled crystals of lithium niobate, for a variety of cuts and propagation directions, with the objective of determining optimum geometries for the efficient wideband generation of acoustic Rayleigh waves. UsingYcut,Zaxis propagating lithium niobate and five‐electrode pair transducers a 100‐MHz delay line has been constructed with an insertion loss of 11.5 dB at a delay of 8.9 &mgr;sec, and a −3‐dB bandwidth of 24 MHz.

ISSN:0003-6951    

DOI:10.1063/1.1652627

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Strong interaction between the wave on the surface of a piezoelectric crystal and the wave on the drifting carriers in a nearby semiconductor is reported. Amplification can result and two‐port net terminal gain of 7 dB at 108 MHz with a delay of 9 &mgr;sec has been observed.

ISSN:0003-6951    

DOI:10.1063/1.1652628

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Fast rise pulses from a GaAs electrooptic switch are used to measure the small signal time response to a step of radiation, of a 20 dB, homogeneously broadened CO2, He, N2laser amplifier. By comparing the observed shape of the time response (rise time ≈ 15 nsec) with theory, the value ofT2, the homogeneous relaxation time, and hence the linewidth is obtained as a function of gas pressure. The doppler broadening (59 MHz), pressure broadening (4.67 MHz/Torr) and gas temperature (372°K) are obtained.

ISSN:0003-6951    

DOI:10.1063/1.1652629

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Light‐induced changes in the refractive index of transition metal doped SrTiO3has been observed. This is the first observation of photochromic index of refraction changes. The measurements are made by observing the variation of transmission of a Fabry‐Perot cavity made of the material studied. Changes in the index of refraction of 1–5 × 10−5per unit change in optical density per centimeter are found. These values agree reasonably well with values calculated from the measured absorption curves.

ISSN:0003-6951    

DOI:10.1063/1.1652630

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

A photon correlation method has been demonstrated to be effective in measuring the width of narrow spectral lines of relatively low intensity. The method has been used to measure the temperature dependence of the diffusion constant in the phenol‐water system. It was found thatD∝ (T − Tc)0.76±0.02for 1° ≲T − Tc≲ 15°C.

ISSN:0003-6951    

DOI:10.1063/1.1652631

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

A general numerical method has been developed for the determination of the modes of propagation, phase velocities, displacements, magnitude and direction of energy flow of elastic surface waves when any layer of anisotropic material is in contact with any underlying semi‐infinite anisotropic crystal. Such characteristics have been calculated for a variety of anisotropic layer and crystal combinations. Typical results are presented.

ISSN:0003-6951    

DOI:10.1063/1.1652633

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

An experiment on the interaction between drifting carriers in semiconductors and slow electromagnetic waves in external circuit was performed. Carriers inn‐type InSb were coupled with slow waves through meander‐type and helix‐type circuits at 77°K. Measurements of transmitted microwave power through these systems give clear evidence for directional coupling by this sort of interaction.

ISSN:0003-6951    

DOI:10.1063/1.1652634

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

The electric‐field‐induced shift to higher energies of the interference peaks of thin tantalum oxide films was observed. The effect has been described in terms of a quadratic electro‐optic coefficientg12which shows a dispersion when the region of absorption is approached.

ISSN:0003-6951    

DOI:10.1063/1.1652635

出版商:AIP    

年代:1968

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.1652636

出版商:AIP    

年代:1968

数据来源: AIP