摘要:

A new dye laser pumping scheme is described in which molecules lying external to a waveguiding film are excited via evanescent fields from an optical pump contained in a waveguide. The excited molecules lying close to the surface then emit into a waveguide mode. An experiment is performed in which Rhodamine 6G in benzyl‐alcohol glycerol mixtures is excited by an optical evanescent field contained in a waveguiding film.

ISSN:0003-6951    

DOI:10.1063/1.1654386

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Water‐vapor absorption lines in the &ngr;2band involving transitions between states of high rotational energy have been found to undergo substantial collisional narrowing in the presence of buffer gases. Measurements were carried out near 5.35 &mgr;m, using tunable lead sulfide selenide semiconductor diode lasers.

ISSN:0003-6951    

DOI:10.1063/1.1654387

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The backscattering of 2500‐keV alpha particles is used to measure the densities of amorphous Si films. The density of amorphous Si is found to be inversely proportional to the electron spin resonance signals. The extrapolated density at zero spins is equal to 1.01 ± 0.02 times that of crystalline Si. The highest density achieved in a real amorphous film was 0.97 ± 0.02 times the crystalline density.

ISSN:0003-6951    

DOI:10.1063/1.1654388

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

An integrated optical modulator is presented that achieved 50% depth of modulation. A double‐ended coupling prism allowed nitrobenzene to be used as the waveguide material. Also, an approximate theory of operation is developed.

ISSN:0003-6951    

DOI:10.1063/1.1654389

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The fabrication of low‐loss (0.1 dB/cm) thin birefringent polymer films on glass substrates is reported. A birefringence of 4.7 × 10−3was measured in polystyrene. In such films, TE and TM modes can be made degenerate by controlling the film thickness. Degeneracy over distances of up to 3 cm was achieved. Such guides may simplify the construction of modulators and other devices requiring degenerate mode operation.

ISSN:0003-6951    

DOI:10.1063/1.1654390

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

An analysis of light‐induced refractive‐index changes (``optical damage'') has been carried out for paraelectric electro‐optic crystals. The results are compared with experimental data taken on several KTN crystals. Both the spatial extent and temporal variations of optical damage are accurately determined by the theory for all crystals tested. The rate at which optical damage occurs can be used to determine the product of absorption, mobility, and lifetime for the material.

ISSN:0003-6951    

DOI:10.1063/1.1654391

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

A photon drag detector with high sensitivity at 10.6‐&mgr; radiation from aQ‐switched CO2laser was developed by usingp‐type tellurium. The observed value of the photon drag signal at 77 K was as high as 5 mV on a 5‐mm‐long sample, perpendicular to thecaxis, when the peak intensity of the incident laser pulse was 1 kW. The photon drag effect is dominantly generated by light holes, so that the polarity of the induced voltage is consistent with that expected on the basis of momentum transfer from photons to holes. There was observed no polarity change over a temperature range in the present experiment, in contrast top‐type germanium. The momentum relaxation time in the light hole band was estimated to be about 10−14sec.

ISSN:0003-6951    

DOI:10.1063/1.1654392

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The thickness of cesium and oxygen deposits required to produce negative electron affinity on semiconductors is not clear from published data. Photoemission measurements show that, for heavily dopedp‐type silicon, negative electron affinity can be achieved with either monolayer or thick deposits of cesium and oxygen, whereas deposits of intermediate thickness are less effective. The results also show that for silicon the lowest effective work function can be achieved by monolayer activation.

ISSN:0003-6951    

DOI:10.1063/1.1654393

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Quenching of fluorescence of common laser dyes is observed and measured as a function of the intensity of an excitation pulse at 3371 Å and the concentration of the dye. The observed effects can be explained by a model where there are sequential absorptions of pump radiation from the ground state and first excited singlet state followed by a radiationless decay, and where molecules can be cycled many times during each excitation pulse.

ISSN:0003-6951    

DOI:10.1063/1.1654394

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The frequency of a 5145‐Å argon‐ion laser has been locked to an absorption line in a molecular beam of I2. The drift of the laser frequency was less than 20 kHz or &Dgr;&ngr;/&ngr;<3 × 10−11for the duration of a run which lasted about 20 min. A molecular‐beam external reference is attractive because transitions observed in the isolated conditions in the beam do not suffer shifts due to collisions or collisional broadening and, if the molecular beam is excited orthogonally, Doppler broadening can be virtually eliminated.

ISSN:0003-6951    

DOI:10.1063/1.1654395

出版商:AIP    

年代:1972

数据来源: AIP