摘要:

Highly (110)-oriented and (100) nearly epitaxial 0.7PMN-0.3PT thin films were deposited on (1012) sapphire and (100)LaAlO3substrates, respectively, using a dip-coating method. Optical waveguide characterization and electro-optic effect measurements of the film on sapphire substrate were demonstrated. Low propagation loss of 4.1 dB/cm and high quadratic electro-optic coefficient of0.75×10−16 (m/V)2were obtained at wavelength of 632.8 nm. Epitaxial PMN-PT thin films will be suitable for integrated optic devices. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121496

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

We report on the design of an imaging microellipsometer enabling the generation of maps of the two ellipsometric angles &Dgr; and &PSgr;. Areas of 60×200 &mgr;m2are imaged at a rate of 1–2 images per minute. By working at angles (45°) much smaller than the Brewster angle (≈73° forSi/SiO2/air) a lateral resolution of 3 &mgr;m and a height resolution of 5 Å is achieved. The performance is demonstrated by thickness measurement of a laterally structured polymer film and a transient thickness measurement of dewetting fluid film ofn-hexadecane on aSi/SiO2wafer. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121497

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

We report on stimulated emission from a solid conjugated methyl-substituted ladder-type poly(paraphenylene). The threshold for stimulated emission as well as the spectral narrowing is measured. Upon exciting within the low energy tail of theS1-S0(0–0) absorption band narrow emission lines offset from the excitation by the energies of the dominant vibrational modes are observed. From these measurements we conclude that vibronic sublevels play a major role in the optical gain mechanism. Hence, the gain mechanism can be explained in terms of molecularly excited states. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121498

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

It is shown that measurements of the effect of optical injection with an external laser on the spectral response of a semiconductor optical amplifier can probe intrinsic properties of a working device. The data demonstrate that under saturated gain conditions the carrier energy distribution within the active layer of a AlGaAs/GaAs amplifier neither shows spectral hole burning nor carrier heating, but only a decreased density. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121499

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

A movement of refractive index grating was observed in two-beam coupling behavior with a low glass-transition temperature photorefractive polymeric film as the poling electric field was discharged. The photorefractive polymeric composite is poly(N-vinylcarbazole) doped with 2,5-dimethyl-4-(p-nitrophenylazo)anisole,N-ethylcarbazole and 2,4,7-trinitro-9-fluorenone in a weight ratio of 25:40:34:1. A theoretical explanation based on electrostrictive effect was given, and some evidential experiments, including degenerate four-wave mixing and Michelson interference measurement were also presented. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121500

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

We demonstrate phase-matched second-harmonic generation from a&lgr;=1.6&mgr;m pump in a GaAs-based waveguide. Phase matching is obtained by using the form birefringence in anAlGaAs/Al2O3multilayer obtained by selective wet oxidation. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121501

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Metal-organic compound molecules were selectively doped into the larger pores of a two-layered porous silicon (PS) which had different pore sizes. PS with a graded pore-size distribution was area-selectively formed by utilizing a thin film mask. Titanium-organic compound molecules were doped into the larger pores and the PS was oxidized to form an optical waveguide. Single-mode transmission of 1.55 &mgr;m wavelength laser light was successfully observed. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121502

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

A photorefractive composite consisting of the polymer poly(N-vinylcarbazole) (PVK) doped with4,4′-n-pentylcyanobiphenyl (5CB) andC60is reported. The material shows no sign of phase separation, is stable, and does not require a plasticizer agent. Gain coefficients over100 cm−1are observed. Measurements of orientational and electro-optic responses indicate that the orientational response is large, but markedly inhibited. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121503

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

A strongly focused Nd:YAG laser beam has been used experimentally to achieve optical trapping and simultaneous rotation of a micro-object about an axis perpendicular to the trapping laser beam axis. The micro-object (12 &mgr;m in diameter), which has shape anisotropy in its interior, can be produced by oxygen reactive ion etching of a fluorinated polyimide film (refractive indexn=1.53). This optically induced rotation of the micro-object in ethanol (n=1.36) is accomplished by utilizing the net radiation pressure force arising from the momentum change of light scattered at the micro-object’s inner walls. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121504

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Tapping-mode near-field scanning optical microscopy (NSOM) employing a cantilevered fiber optic probe is utilized to image the fluorescence from single molecules and samples in aqueous environments. The single molecule fluorescence images demonstrate both the subdiffraction limit spatial resolution and low detection limit capabilities of the cantilevered probe design. Images taken as a function of tip oscillation drive amplitude reveal a degradation in the resolution as the amplitude is increased. With all cantilevered probes studied, however, a minimum plateau region in the resolution is reached as the drive amplitude is decreased, indicating that the tapping mode of operation does not reduce the optical resolution. Images of fluorescently doped lipid films illustrate the ability of the probe to track small height changes (<1.5 nm) in ambient and aqueous environments, while maintaining high resolution in the fluorescence image. When the tip is immersed in water (1.3 mm), the cantilevered NSOM tip resonance, 25–50 kHz, shifts approximately 100–150 Hz, the amplitude dampens less than 40&percent; and theQfactor is reduced from 300–500 to 100–200. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121505

出版商:AIP    

年代:1998

数据来源: AIP