摘要:

We describe a novel ultrafast photodetector based upon combining the Dember effect and optically generated fine carrier gratings. We present experimental data on prototype devices, and demonstrate that this device’s response time is limited neither by the carrier lifetime nor by the saturation‐velocity transit time.

ISSN:0003-6951    

DOI:10.1063/1.98760

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

An optical electroabsorption waveguide modulator is described based on the quantum‐confined Stark effect in an InGaAs/InP multiple quantum well waveguide. The optical modulator has a high on/off ratio (47:1) with very low insertion loss (2.9 dB) and a 3‐dB modulation bandwidth of 3.0 GHz at 0.1 mW optical input power.

ISSN:0003-6951    

DOI:10.1063/1.98761

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We report the first demonstration of a nonlinear coupler switch capable of substantially complete all‐optical switching at subpicosecond rates with no light‐induced thermal effects.

ISSN:0003-6951    

DOI:10.1063/1.98762

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Monolithic two‐dimensional arrays with light emission normal to the surface have been obtained by fabricating edge‐emitting quantum well GaAs/AlGaAs lasers with deflecting mirrors adjacent to both laser facets. The facets and mirrors were formed by ion beam assisted etching. Proton bombardment between adjoining lasers was used to prevent lasing in the transverse direction. At the highest pulsed current used in these experiments, 10.5 A, the power output of a 22‐element array was 1.6 W, which corresponds to a power density of 160 W cm−2. At this level, the power output was still linear with current.

ISSN:0003-6951    

DOI:10.1063/1.98763

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A compact narrow linewidth semiconductor laser is described. An emission linewidth of 135 kHz at 5 mW of output power is obtained from a 1.5‐&mgr;m semiconductor laser butt coupled to an external resonant optical reflector (ROR). The ROR, made with dielectric waveguides on silicon substrate, has transmission and reflection bandwidths as narrow as 0.35 A˚.

ISSN:0003-6951    

DOI:10.1063/1.98764

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Single‐crystal &agr;‐Al2O3films are, for the first time, successfully grown on sapphire wafers above ∼600 °C by the molecular layer epitaxy (MLE) method using AlCl3vapor and a He 15%O2gas mixture. The average growth rate observed barely depends on the substrate temperature, being ∼0.09 nm per cycle of gas transport, under the used growth conditions. The epitaxial growth of &agr;‐Al2O3films on single‐crystal Nb films at ∼500 °C by the MLE method is also confirmed for the first time.

ISSN:0003-6951    

DOI:10.1063/1.98765

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The results of an experimental and theoretical study of consolidated, acid‐cleaned fused glass beads are presented. Measurements of the spin‐lattice lifetime, permeability, and capillary pressure curves in conjunction with digital analysis of scanning electron microscope images and theoretical modeling lead to a description of this porous material consistent with the fast diffusion picture of nuclear magnetic relaxation.

ISSN:0003-6951    

DOI:10.1063/1.98766

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A cw argon laser was used to oxidize crystalline silicon in dry oxygen. Under otherwise identical conditions, two visible wavelengths were used to identify possible nonthermal contributions to the reaction. With a simple technique to amplify small differences in the growth rate we have confirmed that the reaction is primarily thermally controlled and that there is a photonic enhancement to Si oxidation. A simulation has also provided some initial quantitative evaluation of the process.

ISSN:0003-6951    

DOI:10.1063/1.98767

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We have used the voltage contrast effect to image deep level domains in semi‐insulating (SI) GaAsn‐i‐nresistor structures. Our samples consisted of SI, undoped, liquid encapsulated Czochralski material with alloyed AuGe/Ni contacts at spacings from 1.3 to 2.27 mm. By viewing the contact side of the samples with a scanning electron microscope while the devices were biased in the oscillation region, we observed domain formation and motion from cathode to anode in real time. Long range potentials in the GaAs were observed by viewing the polished back surface of the samples. That is, the domains which are launched from the front contacts were clearly evident in voltage contrast measurements on the back of the sample. Also, because of the nonuniform charging of the semiconductor surface by the electron beam, we observed interactions between the propagating domains and the cellular dislocation structure in the SI GaAs.

ISSN:0003-6951    

DOI:10.1063/1.98768

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

By using a combination of deep level transient spectroscopy (DLTS) and electron paramagnetic resonance techniques applied to samples of varying compositions, we identify the bistable defect atEc−0.17 eV in irradiatedn‐type silicon as a carbon interstitial‐carbon substitutional pair. It arises upon annealing of interstitial carbon, which is also the precursor to a remarkable recently discovered four‐level multistable defect which we now tentatively identify as a carbon‐phosphorus pair. We demonstrate a new simple method for distinguishing the bistable carbon‐carbon pair defect from the oxygen‐vacancy pair under the same DLTS peak.

ISSN:0003-6951    

DOI:10.1063/1.98717

出版商:AIP    

年代:1987

数据来源: AIP