摘要:

A new technique for fabricating active planar waveguide devices is reported. This process, based on the thermal bonding of precision finished crystal or glass components, allows waveguides to be assembled from very dissimilar materials and could be applied to a wide range of solid state laser or other optical media. The waveguide propagation losses, inferred from the laser performance, are found to be 0.7 dB/cm forNd:Y3Al5O12bonded toY3Al5O12,Nd:Y3Al5O12bonded to glass, and 0.4 dB/cm forNd:Gd3Ga5O12bonded toY3Al5O12devices. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119846

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Wide-stripe, 0.97 &mgr;m emitting Al-free InGaAs(P)/InGaP/GaAs broad-waveguide separate confinement heterostructure quantum-well lasers demonstrate a record value for quasicontinuous wave (QCW) output power: 14.3 W (100-&mgr;m-wide stripe, 100 &mgr;s-wide pulses); and reach catastrophic optical mirror damage (COMD) in QCW operation at an optical power density of22.5 MW/cm2;that is, 40&percent; higher than COMD levels in cw operation. The devices have low internal losses(&agr;i=1 cm−1)and high external differential quantum efficiency (86&percent; for 2-mm-long lasers), and exhibit only 10–20 °C temperature rises in the active region at 10 W QCW power. We also show that long-cavity, large-contact-area devices exhibit relatively little spectral broadening with increased output power. ©1997 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.119847

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We demonstrate that mixing insulating oxide nanoparticles into electroluminescent polymer materials results in increased current densities, radiances, and power efficiencies in polymer light emitting diode devices. For low driving voltages, an order of magnitude increase in current density and light output is achieved with minimal loss in device lifetime. At 5 V, we achieve radiances of 10 000cd/m2with external quantum efficiencies ∼1&percent; for nanoparticle/MEH–PPV composite films. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119848

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

In this letter, we investigate the optical properties of packed monodisperse silica submicron spheres by means of optical transmission measurements. The results are compatible with a three dimensional face centered cubic order in these solid structures. The lattice parameter of these structures, and therefore their optical properties, can be easily tuned through the sphere size (between 200 and 700 nm) thus covering the whole visible and near infrared spectrum. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119849

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Organic light-emitting devices have been prepared with multilayer Al–Li–Al cathodes in an ultrahigh vacuum molecular beam deposition system. The optimum device characteristics are obtained when there is a single Al layer separating the Li layer from the organic materials.Ab initiomolecular dynamics calculations of the Al–Li interaction clarify the role of Al as a blocking layer to Li diffusion into the organic films as well as the behavior of the device when the thickness of this Al interfacial layer is changed. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119850

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

A large-signal, time domain semiconductor laser model that incorporates propagation effects within the cavity and a microwave circuit simulator are used to investigate distributed microwave effects on gain-switching performance. It is shown that the position of the feed point to the top electrode can have a significant influence on the harmonic content of the generated pulses, which is an important consideration in microwave/millimeter-wave signal generation schemes. ©1997 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.119851

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

In this letter, we present the results of an experimental study of low-temperature-grown GaAs, which clearly resolves separately both carrier trapping and recombination processes. We extend our previous model to account for the observed carrier dynamics, and show how the material growth and annealing conditions can be adjusted to optimize the material properties for all-optical device applications. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119852

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We report on light scattering measurements in guest/host photorefractive polymers doped with different polar dyes as a function of temperature and sample composition. Crystallization processes of the polar dye are found to follow a nucleation and growth mechanism. The structure and melting point of the polar dye, the storage temperature, and the amount of plasticizer are shown to exert a major influence on the shelf lifetime of the samples. New composites with high efficiency and long shelf lifetime are presented. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119612

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We presented a novel type of orientational photorefractive device, consisting of liquid crystals (LCs) sandwiched with photoconductive polymer films across the insulated polymer films. The photoexcited charges were generated in the photoconductive layers and eventually become trapped in the dark areas at the insulated polymer surfaces. The resulting space charge field reoriented the LC molecules and the holographic gratings were generated. The strong beam coupling effects were observed and the refractive index modulation&Dgr;nwas estimated to be of the order of3.6×10−3.©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119613

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Cylindrical microdischarge cavities 200–400 &mgr;m in diameter and 0.5–5 mm in depth have been fabricated in silicon and operated at room temperature with neon or nitrogen at specific power loadings beyond10 kW/cm3.The discharges are azimuthally uniform and stable operation atN2and Ne pressures exceeding 1 atm and∼600 Torr,respectively, has been realized for 400 &mgr;m diameter devices. Spectroscopic measurements on neon discharges demonstrate that the device behaves as a hollow cathode discharge for pressures>50 Torr.As evidenced by emission from Ne andNe+(2P,2F)states as well asN2(C→B)fluorescence (316–492 nm), these discharge devices are intense sources of ultraviolet and visible radiation and are suitable for fabrication as arrays. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119614

出版商:AIP    

年代:1997

数据来源: AIP