摘要:

Nearly degenerate four‐wave mixing (NDFWM) in a traveling‐wave semiconductor laser amplifier is demonstrated by simultaneously injecting two lights of slightly different frequencies in the same direction. A new frequency light at an expected frequency for NDFWM is observed with the same order of output as that of the injected light. The output power ratio of the three beams is strongly dependent on the sign of the frequency detuning. Theoretical analysis, in which the carrier rate equation is coupled with nonlinear Maxwell’s equations, explains the experimental results well. The observed behaviors are attributed to a unique third‐order nonlinearity stemming from saturation‐induced refractive index change in the semiconductor gain medium.

ISSN:0003-6951    

DOI:10.1063/1.99004

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We used metalorganic chemical vapor deposition to fabricate a planar‐embedded InGaAsP/InP heterostructure laser with a semi‐insulating InP current‐blocking layer. The laser exhibits cw operation with a low, 20 mA threshold current and a high external differential quantum efficiency of 40% at room temperature. Measurements have also shown a small‐signal frequency response of 10 GHz due to an extremely small parasitic capacitance of 3.5 pF.

ISSN:0003-6951    

DOI:10.1063/1.98789

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A modified hollow‐bore ridge waveguide, utilizing a staggered ridge geometry, has been used successfully to obtain single‐frequency operation from an array of CO2waveguide lasers. The gain volume of the array is equivalent to six waveguide lasers of 37 cm length and 2.25×2.25 mm2cross section. The output power from the sealed‐off device reached 68 W cw. Stable single‐frequency operation in the antisymmetric supermode was observed.

ISSN:0003-6951    

DOI:10.1063/1.98790

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We present the first demonstration of interlayer, or vertical, directional grating coupling using a permanently incorporated corrugated layer grating. Based on an InP/InGaAsP antiresonant reflecting optical waveguide (ARROW) geometry grown by chemical beam epitaxy and metalorganic chemical vapor deposition, we have achieved a large mode contradirectional grating‐coupled waveguide photodetector with a spectral response peak 9 A˚ wide. The ‘‘optical bus’’ capabilities of the vertically coupled ARROW structure make this device suitable for optical integration.

ISSN:0003-6951    

DOI:10.1063/1.98791

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A narrowband (5 GHz) electron beam pumped XeF oscillator/amplifier, lasing at 353.2 nm over a 1‐&mgr;s pulse duration, has been demonstrated. Line selection, bandwidth narrowing, and near‐diffraction‐limited output are achieved by using an echelle grating and an intracavity solid e´talon in a stable oscillator configuration. The amplifier features an off‐axis design and yields output energies ≳0.8 J. The oscillator and amplifier are located in the same gas chamber and are transversely pumped by the same electron beam. A Fabry–Perot interferometer together with a streak camera is used to verify narrowband operation over the entire pulse duration.

ISSN:0003-6951    

DOI:10.1063/1.98792

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A noncontacting technique has been developed to measure the thickness of thin metal sheet by using a pulsed laser to generate both symmetric and antisymmetric Lamb waves. These have been detected with a laser interferometer. Analysis of the waveforms allows an estimation of the sheet thickness and accuracies to within 2% are attainable on sheets as thin as 27 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.98793

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A new method to grow stress‐free GaAs on bent Si substrates is proposed and demonstrated by metalorganic chemical vapor deposition. The stress produced by the thermal expansion coefficient difference of Si and GaAs is compensated by the external mechanical strain applied in the substrate at high temperature. The photoluminescence peak energy of GaAs on Si becomes almost the same as that of the stress‐free GaAs on GaAs grown by liquid phase epitaxy by applying this method.

ISSN:0003-6951    

DOI:10.1063/1.98794

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

High‐resolution spectroscopy of protons incident under nonchanneling condition and scattered by 12° on Pd‐ and Au‐deposited Si(111) surfaces has been employed for direct layer‐by‐layer analysis of the depth distribution of Au and Pd. For nearly monolayer deposition at room temperature, most of the Au atoms are found to remain on the silicon surface, while the Pd atoms are found to be distributed over the two layers, with the palladium composition not exceeding that of Pd2Si. We also found that the most probable energy loss of protons scattered from the Au‐deposited surface is sensitive to the depth of the Au atoms on the surface.

ISSN:0003-6951    

DOI:10.1063/1.98743

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

This letter reports the growth of high‐efficiency Al0.3Ga0.7As solar cells by molecular beam epitaxy. As the growth temperature increases from 650 to 750 °C, the concentration of midgap electron traps in the active layers decreases from 4×1015to less than 3×1013cm−3and the hole diffusion length in the layers improves from 2.0 to 2.6 &mgr;m. For cells grown at 750 °C, an efficiency of 14.6% (AM1.5, 100 mW/cm2for an active area) is obtained.

ISSN:0003-6951    

DOI:10.1063/1.98744

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Deep level transient spectroscopy was applied to study silicon epitaxial layers of varying thickness grown on silicon‐on‐insulator substrates formed by oxygen implantation. For 3‐&mgr;m‐thick layers no traps were detected. For 1.0‐, 2.0‐, and 2.5‐&mgr;m‐thick layers electron traps were found with levels 0.34, 0.32, and 0.37 eV below the conduction‐band edge, and corresponding capture cross sections of ∼2.0×10−7, 6.0×10−18, and 5.0×10−7cm2. These levels were found to be uniformly distributed across the wafer. It was also observed that the trap concentration is a decreasing function of epilayer thickness.

ISSN:0003-6951    

DOI:10.1063/1.98745

出版商:AIP    

年代:1987

数据来源: AIP