摘要:

Analysis of data from Nd:YAG indicates a substantial experimental divergence from the standard theoretical results predicted for nonradiative energy transfer. A new model for correlated ion placement in the crystal is shown to completely explain the discrepancy.

ISSN:0003-6951    

DOI:10.1063/1.101369

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We describe a photonic integrated circuit composed of three 1.5 &mgr;m wavelength multiple quantum well tunable lasers with a passive optical power combiner and an optical output amplifier. Independent channel operation with 1–2 mW/channel output power is demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.101164

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The effective optical and magneto‐optical constants of a series of Cu/Co multilayer films are determined experimentally and compared with a theoretical thin‐film model based on the bulk optical constants of Cu and Co. In the multilayer series, the atomic percentages of Cu and Co were kept fixed and the period varied from 0.4 to 13.6 nm. Deviations from bulk‐like behavior in the effective optical constants are observed for multilayers with periods less than 3 nm.

ISSN:0003-6951    

DOI:10.1063/1.101165

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A method of growing high quality 4‐(N,N‐dimethylamino)‐3‐acetamidonitrobenzene (DAN) single crystals is presented. Crystal plates with dimensions of up to 10×5×2 mm3were produced and optically characterized. The transparency region extends from 485 to 2270 nm. Large birefringence and strong dispersion of the refractive indices were measured allowing two branches of type I and two of type II phase‐matched second‐harmonic generation. From effective second‐order nonlinear optical susceptibilities measured along the branches all nonlinear susceptibilities were evaluated, the highest beingd23=(50±15) pm/V.

ISSN:0003-6951    

DOI:10.1063/1.101166

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Direct measurements of the change in refractive index (&Dgr;n) as a function of applied electric field for polydiacetylene paratoluenesulfonate are reported. The magnitude of the effect is compared to that observed in GaAs, and a figure of merit with respect to device application is discussed.

ISSN:0003-6951    

DOI:10.1063/1.101167

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

All‐optical switching of femtosecond pulses in AlGaAs waveguides is investigated using a novel time division interferometric technique which eliminates thermal imbalances. In addition to an instantaneous refractive index nonlinearity, free‐carrier generation via two‐photon absorption produces a response of several hundred picoseconds duration.

ISSN:0003-6951    

DOI:10.1063/1.101168

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A new type of low‐pressure gas switch is described. The switch is triggered by an electron beam that is emitted from the surface of a ferroelectric sample. The electron beam is generated within the hollow cathode and ejected through a hole of arbitrary shape into the main gap of the switch. The beam current and the electron energy can be chosen such that breakdown is achieved with small jitter. The switch with its ferroelectric trigger requires neither heating nor an auxiliary gas discharge. The fast spontaneous polarization change &Dgr;Ps, which is the cause of electron emission, is induced by a high‐voltage pulse from an electronic switching circuit.

ISSN:0003-6951    

DOI:10.1063/1.101169

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

A Nd:YAG laser was used to reflow Cu/Pb‐Sn solder joints. The joints were reflowed with 60 W, 1 s laser pulse. The resulting intermetallic microstructure was examined with scanning electron microscopy, energy dispersive x‐ray analysis, and x‐ray diffraction. In addition to the intermetallic layer expected to form at the solder‐base metal interface, an intermetallic precipitate was found to form in the bulk solder. X‐ray diffraction data established the identity of the intermetallic as &eegr;‐Cu6Sn5.

ISSN:0003-6951    

DOI:10.1063/1.101563

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The characteristics of a new type of AlGaAs/GaAsp‐i‐nphotodiode are reported. Indium tin oxide forms the contact to the upper AlGaAs layer and serves also as an antireflection coating. Our devices show very low dark currents (20–300 pA at 5 V reverse bias for devices of 20–200 &mgr;m diameter), high speed (full width at half maximum <60 ps), and high sensitivity (61% external quantum efficiency) at 1 V bias. A microwave analysis of the diode is presented.

ISSN:0003-6951    

DOI:10.1063/1.101170

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Hydrogenated amorphous silicon (a‐Si:H) thin‐film transistors (TFTs) which utilize two layers of amorphous silicon nitride with different composition as a gate insulator have been studied. The field‐effect mobility, subthreshold slope, and stability of ana‐Si:H TFT are enhanced by inserting a thin silicon‐rich nitride layer between thea‐Si:H and the gate insulator. The improvement of these characteristics appears to be due to both the decrease of the interface state density between thea‐Si:H and the top silicon‐rich nitride layer, and the good dielectric quality of the bottom nitride layer.

ISSN:0003-6951    

DOI:10.1063/1.101171

出版商:AIP    

年代:1989

数据来源: AIP