摘要:

The properties of planar waveguides and directional couplers fabricated by potassium/sodium ion exchange in semiconductor‐doped glasses are described.

ISSN:0003-6951    

DOI:10.1063/1.97335

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The switching time of a double heterostructure optoelectronic switch is investigated using an optical input. A switch‐on time of 5–10 ps is obtained using a discrete microwave package. The fall time of 10 ns is limited almost totally by the parasitic capacitance of the package. The switching operation shows the unique ability to turn on and off with the incident optical signal.

ISSN:0003-6951    

DOI:10.1063/1.97336

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Nonperiodic codirectional power coupling between the polarization eigenmodes of a highly birefringent fiber, possessing propagation constants &bgr;xand &bgr;y, is possible with the assistance of contradirectionally propagating modes. When the fiber lengthLis adjusted so that (&bgr;x−&bgr;y)L=2m&pgr;(m=±1, ±2,...) and the fiber ends are unequally excited, the coupling term gives rise only to a nonreciprocal phase between counterpropagating waves.

ISSN:0003-6951    

DOI:10.1063/1.97337

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The lowbitron—a longitudinal wiggler beam interaction device—as a novel source of submillimeter wave radiation was proposed and analyzed theoretically by McMullin and Bekefi [Phys. Rev. A25, 1826 (1982)]. This letter reports the first experimental measurements of lowbitron radiation obtained with a 740‐kV, 400‐A electron beam. The measured power spectra in theW‐band range for different wiggler field periods agree with the lowbitron interaction theory. They match the intersection points of the shifted fast cyclotron wave dispersion relation &ohgr;−(k+kw)v∥−&OHgr;0/&ggr;=0 and the TE01electromagnetic waveguide mode.

ISSN:0003-6951    

DOI:10.1063/1.97338

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A hybrid growth technique has been used to fabricate low threshold 1.51 &mgr;m InGaAsP buried crescent injection lasers with a semi‐insulating current confinement layer. The technique involves a first stage of low pressure metalorganic chemical vapor deposition followed by a liquid phase epitaxy stage. The lasers exhibit cw threshold currents as low as 12 mA at 25 °C, high yield, differential quantum efficiency over 41%, and output power more than 18 mW. Small‐signal modulation response to 3.5 GHz has been obtained. The lasers show an initial small degradation rate of 1%/kh at 50 °C which gives an estimated operating lifetime of 47 years at 25 °C.

ISSN:0003-6951    

DOI:10.1063/1.97339

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Optical power in excess of 25 W from one facet has been obtained from a 1‐cm monolithic AlGaAs laser array for a pulse width of 150 &mgr;s (quasi‐cw operation). The array consists of twenty 40‐stripe lasers spaced along the bar, with etched grooves between each region to prevent transverse lasing and amplified spontaneous emission. About 80% of the facet width is utilized for active laser emission.

ISSN:0003-6951    

DOI:10.1063/1.97340

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We describe a photoacoustic ultrasonic imaging system that can provide separate acoustic information on a thick substrate and a thin coating simultaneously. This is achieved by generating an ultranarrow longitudinal pulse on the opaque layered sample, and detecting the series of substrate and coating echoes in high time resolution. The echo times, attenuations, and acoustic dispersions in each series provide information on the substrate or coating separately. New photoacoustic images of coatings and of substrates for coated ceramic substrates are presented.

ISSN:0003-6951    

DOI:10.1063/1.97341

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A silicon‐on‐insulator (SOI) structure was formed by implanting 150 keV O+ions into a single‐crystal,n‐type Si. The substrate temperature during implantation,Ti, was regulated within the range of 450–750 °C. Implanted samples were subsequently annealed at 1300 °C for 2–5 h and analyzed using transmission electron microscopy, Rutherford backscattering, the spreading resistance probe, and secondary ion mass spectroscopy. It is shown that the substrate temperature during oxygen implantation strongly influences the properties of the SOI structure after the high‐temperature annealing: the residual oxygen concentration within the Si surface layer strongly depends onTiand correlates with the carrier density, indicating the presence of oxygen‐related thermal donors.

ISSN:0003-6951    

DOI:10.1063/1.97342

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

An indentation technique is described for measuring the shear strength of the interface between a thin film and a rigid substrate. A simple elastic/plastic analysis is used to describe the experimental results and good agreement between the two is found. The method may also be used to estimate the interfacial toughness so that the important parameters characterizing both initiation and propagation of adhesive failure may be determined from one simple experiment. The analysis is extended to describe the effect of residual stress in the film. Also, the stresses around a pinhole defect in a stressed film are examined.

ISSN:0003-6951    

DOI:10.1063/1.97343

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The annealing kinetics of the dominant defect [E(0.32 eV), &sgr;n=8×10−16cm−2] induced in virgin Czochralski‐grownn‐type ⟨100⟩ 1–5 &OHgr; cm silicon by Nd‐YAG laser (1.6 J cm−2, 0.53 &mgr;m) irradiation has been studied within the temperature range 500–650 °C using rapid and conventional thermal processing. With deep level transient spectroscopy measurements, we have observed an annealing rate increase about 30 times faster in the rapid thermal annealed (RTA) samples, than in those heat treated in a conventional furnace (CTA) with an activation energy difference &Dgr;EA&bartil;0.31 eV between the two processes, the latter requiring the higher energy. This difference results from ionization‐enhanced annealing of this defect during RTA processing, a phenomenon which is markedly reduced in CTA‐processed samples.

ISSN:0003-6951    

DOI:10.1063/1.97344

出版商:AIP    

年代:1986

数据来源: AIP