摘要:

A new type of substrate-mode holographic collimating and beam shaping element for laser diodes is presented. Techniques and design considerations are described. A sample is fabricated and its function is demonstrated. It has many merits, such as easy fabrication, low cost, compactness of monolithic structure, and is easily used. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118441

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Third harmonic generation near the focal point of a tightly focused beam is used to probe microscopical structures of transparent samples. It is shown that this method can resolve interfaces and inhomogeneities with axial resolution comparable to the confocal length of the beam. Using 120 fs pulses at 1.5 &mgr;m, we were able to resolve interfaces with a resolution of 1.2 &mgr;m. Two-dimensional cross-sectional images have also been produced. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118442

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Third-order nonlinear optical properties of chalocogenide glasses were investigated through third-harmonic generation (THG), optical Kerr shutter (OKS), and degenerate four-wave mixing (DFWM) measurements. We examined the dependence of the THG susceptibility on the absorption edge, thereby showing that the susceptibility rapidly increased as the absorption edge red shifted. Moreover, the THG susceptibility was compared with the OKS susceptibility. It was found that both susceptibilities almost coincided within the range of experimental errors. The OKS and DFWM experiments indicated that a high-speed compact optical switching device was obtained using the chalcogenide glasses. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118443

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

In a polyconjugated main chain polymer strip waveguide the nonlinear, nonresonant refractive indexn2was measured by monitoring the signal spectrum broadening due to self-phase modulation. The two photon absorption coefficient&agr;2was obtained by calibrating the inverse transmission measurement. The nonlinear coefficients were determined to ben2=0.85×10−14 cm−2/W and&agr;2=0.08 cm/GW at a wavelength &lgr;=885.6 nm. The used polymer was poly[1,4-phenylene1,2-di(phenoxyphenyl)vinylene]. The result is in good agreement with interferometer measurements. The material is suitable for all-optical switching. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118462

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Stimulated emission at 5.1 &mgr;m was demonstrated from a broad areaIn1−xAlxSb/InSbheterostructure diode laser grown by molecular beam epitaxy. For a 5 &mgr;s pulse and a 500 Hz repetition rate the threshold current density was 1480A cm−2at 77 K and the maximum operating temperature was 90 K at a current density of 2680A cm−2. Maximum peak power output was estimated to be 28 mW per facet at 77 K and 4500A cm−2.

ISSN:0003-6951    

DOI:10.1063/1.118444

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Light emitting devices were fabricated in planar (surface cell) configurations with low operating voltage. Polymer blends composed of a red or green color luminescent polymer and solid state electrolyte were used as the active materials. Under external bias, electrochemical doping occurs in the vicinity of the contact, and a dynamicp-njunction forms between the electrodes. Light emission is observed in the junction area at bias voltages greater than 2 V, reaching102cd/m2at voltage well below 5 V. The planar configuration allows display devices to be hybridized with integrated circuits on a silicon wafer. On transparent substrates, such as glass or plastic films, light emission can be viewed from both sides of the device. Emissive displays in the planar surface cell configuration can be fabricated using roll-to-roll processing at room temperature without need for vacuum equipment. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118445

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We observe modification of the spontaneous emission spectrum emitted through the substrate of a quantum well semiconductor laser. The effect is driven by the proximity of the quantum well active region to the p-side electrical contact of the device, representing an excellent example of cavity quantum electrodynamics. Modification of the spontaneous emission rate and spectrum can be substantial; it must be accounted for in order to infer modal gain or carrier heating phenomena in the device correctly. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118446

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Time-dependent acoustic oscillations driven by stochastic thermal force have been observed by means of transmission electron microscopy. An electron-beam current passing in the vicinity of the edge of the vibrating sample, and thereby modulated, was led through an aperture at the image plane and measured with the electron counting technique as the power spectral density function, allowing the resonant frequency and theQfactor to be found. This enables estimation of the Young’s modulus and the internal friction. The method can be extended to the investigation of the elastic properties of nanoscaled samples. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118447

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The origin of nonlinearity inKTiOPO4was investigated quantitatively from the chemical bond viewpoint. All constituent chemical bonds in this crystal were considered and their contributions to the total linearity and nonlinearity were quantitatively determined. Calculated results agree satisfactorily with experimental data in both signs and numerical values. These results show us thatTiO6groups and P(1)O4groups have relatively larger linear contributions and the nonlinearity derives fromKOx (x=8,9)groups and P(2)O4groups. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118448

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The nucleation and growth conditions ofc-BN films were studied in low-pressure inductively coupled plasma enhanced chemical-vapor deposition. The threshold sheath potentials needed for the nucleation and the growth ofc-BN were sustained by two stepVsheathdeposition. The threshold sheath potential for the growthVsheathgwas found to be significantly lower than the threshold value required for nucleationVsheathn.Under our experimental condition, the values ofVsheathgandVsheathnwere found to be 45 and 65 V. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118449

出版商:AIP    

年代:1997

数据来源: AIP