摘要:

A new technique for measurement of collision‐broadened homogeneous linewidths, using the nonlinear interaction between two traveling waves, is described. Measurements of homogeneous linewidth for the 6328‐Å neon line in neon and helium‐neon discharges are presented.

ISSN:0003-6951    

DOI:10.1063/1.1652533

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Experimental results are presented which indicate two forms of damage in CdS irradiated by either a normalmode orQ‐switched ruby laser at power densities near 108W/cm2. The primary damage occurs as a deep crater coaxial with the incident laser beam. This crater contains many periodic transverse fractures whose spacing suggests a phonon frequency of ∼ 100 MHz, and which is attributed to stimulated Brillouin scattering. The second site is in the region where the refracted light beam exits from the crystal.

ISSN:0003-6951    

DOI:10.1063/1.1652534

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Data are presented showing that lightly doped or relatively pure GaAs lases basically by a band‐to‐band recombination transition at a photon energyat thresholdof 1.495 eV ≈Eg− 0.015 eV (∼77°K). The ∼0.015‐eV energy reduction from bandgap, which is greater than the exciton binding energy of 0.0034 eV (∼77°K) and unlike the exciton energy is dependent upon carrier concentration, occurs because of many‐body, electron‐hole‐lattice (EHL) interactions.

ISSN:0003-6951    

DOI:10.1063/1.1652535

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Dye solution lasers are observed to lase at shorter wavelengths when laser pumped than when flashlamp excited. A comparison of the computed frequency‐ and time‐dependent gains for the two pumping methods explains this behavior and the observedQdependence of the lasing frequency. This treatment also suggests a new technique for frequency tuning dye lasers.

ISSN:0003-6951    

DOI:10.1063/1.1652536

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

The wavelength spectrum of an organic dye laser (DTTC in ethanol) pumped by aQ‐switched ruby laser has been measured as a function of temperature (−117°C to +78°C) for several dye concentrations. Absorption and fluorescence spectra were also obtained. The results are in qualitative agreement with the model of a vibrationally broadened two‐level system, each of which is separately thermalized.

ISSN:0003-6951    

DOI:10.1063/1.1652537

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

By combining optical strain‐birefringence with stroboscopic illumination, acoustoelectric domains in CdS have been made visible. Domain widths of 50 to 200 &mgr; have been observed in crystals with drift field perpendicular to theCaxis. In crystals withEparallel toCaxis the domain travels at 30° with respect toCand forms a complex reflection pattern.

ISSN:0003-6951    

DOI:10.1063/1.1652538

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

In conjunction with studies relating to high‐power CO2laser windows the linear absorption coefficient &agr; of Cr‐doped GaAs was measured by means of calorimetric techniques. It was found that &agr; ≈ 0.02 cm−1, at room temperature. This result is shown to be consistent with theoretical considerations: At 10.6 &mgr;, the lattice absorption of GaAs stems from the existence of a fourth‐order electric moment and does not involve the fundamental resonance.

ISSN:0003-6951    

DOI:10.1063/1.1652539

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

A new reflective optical storage effect has been found in mixtures of certain nematic liquid crystals and cholesteric liquid crystals. When subjected to a dc field, the initially clear material becomes milky white and remains in this state when the field is removed. The material can be rapidly switched back to its clear state by an audio‐frequency signal. A preliminary model based on the principle of a field‐induced emulsion gives rough agreement with experiment.

ISSN:0003-6951    

DOI:10.1063/1.1652540

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

The wavelength shift phenomena of a dye laser and a dye laser oscillation pumped by another dye laser were studied by introducing two dye cells in a cavity. Simultaneous laser oscillations at different wavelength ranges were obtained, and a 4‐level laser mechanism of the dye laser system is discussed.

ISSN:0003-6951    

DOI:10.1063/1.1652541

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Hall and photo‐Hall effects have frequently been used to distinguish between a ``numbers'' mechanism (assumed if &Dgr;n≠ 0 and &Dgr;&mgr; = 0), and a ``barier'' mechanism (assumed if &Dgr;n= 0 and &Dgr;&mgr; ≠ 0) for photoconductivity in possibly inhomogeneous materials. Consideration of a simple model for an inhomogeneous material shows that a wide variety of effects can be obtained in a material with only resistivity variations and withoutp‐njunction barriers. In particular it may be shown that in such a model without barriers, either &Dgr;n≠ 0 and &Dgr;&mgr; = 0, or &Dgr;n= 0 and &Dgr;&mgr; ≠ 0, may be obtained experimentally, depending only on the resistivity ratio between different portions of the material.

ISSN:0003-6951    

DOI:10.1063/1.1652542

出版商:AIP    

年代:1968

数据来源: AIP