摘要:

AlGaAsSb/InGaAsSb single-quantum-well (SQW) laser diodes emitting at 2 &mgr;m were fabricated and tested. At 10–15 °C, the uncoated SQW lasers with 2–3 mm cavity lengths exhibit a threshold current density of115 A/cm2,a continuous-wave output power of 1.9 W, a differential efficiency of 53&percent;, and a quasi-continuous-wave output power of 4 W. Their performance deteriorates rapidly as output losses increase beyond10 cm−1.©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118747

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We demonstrate that semiconductingCdF2crystals doped with gallium provide an efficient medium for optical storage of information in static and dynamic regimes in a temperature range close to 300 K. Ga is a bistable center inCdF2crystals. Illumination by visible and UV light below 500 nm causes phototransformation of these centers from a deep-localized to a shallow-hydrogenic state. They are separated by a vibronic barrier that causes metastability below 250 K. The phototransformation changes the local polarizability, and thus, the local refractive coefficient. This, in turn, allows writing a phase hologram with a diffraction efficiency and decay time being temperature dependent with the activation energyEact=0.65±0.1 eV.A spontaneous decay of the grating is caused by a thermal recovery of the Ga impurity from the metastable hydrogenic state to the localized ground state. The writing is a local process. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118748

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Using standard microelectronic techniques, we have fabricated arrays of infrared metallodielectric photonic crystals (IR MDPCs) on silicon substrates. The metallic “atoms” are located on a three-dimensional (100)-oriented face-centered-cubic lattice. Resonant stop-band characteristics have been measured with rejection levels of up to 20 dB and widths of up to 83&percent; of the center frequency. We demonstrate structures with stop bands across the midinfrared wavelength range from 2 to 12 &mgr;m. Angular studies of the photonic stop bands show an insensitivity to incident angle for some of the structures. The IR MDPC results are compared with measurements made on microwave-scale MDPC structures to help in understanding the infrared results. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118749

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We prepared a polymer containing pendant norbornadiene (NBD) moieties,P(MMA0.43-co-GMA0.57-PNCA),and measured absorbance and refractive index spectra before and after photoisomerization of norbornadiene moieties. Large photoinduced refractive index changes of∼0.01were obtained at 632.8 nm, the region far from the absorption band. A quantum yield of 0.50 was obtained for the photoisomerization of NBD moieties in this polymer. These values are sufficient to make efficient channel waveguides by photoisomerization. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118750

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We report a detailed spectroscopic study of the electronic states in ultranarrow ZnS/ZnSe superlattices. The conduction to valence band offset ratio is found to be around 8:92 in nearly pseudomorphic structures. The impact of the weak electron confinement on the optical and electronic properties is discussed, with special attention to laser applications. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118751

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We demonstrate optical response from a side-injection light-controlled bistable laser diode buried with semi-insulating InP using hydride vapor phase epitaxy. The buried surface around both the ⟨110⟩ and⟨−110⟩oriented mesas is flat. The bistable operation is obtained by applying control voltage to the saturable absorption region. After optimization of the device parameters, we obtained error-free operation at a bit rate as high as 2.5 Gbit/s. ©1997 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.118752

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

A multifunctional conjugated carbazole trimer has been designed as a monolithic photorefractive material. The photorefractive properties of this carbazole trimer were demonstrated by a two-beam coupling experiment at a wavelength of 532 nm. An asymmetric energy transfer between the two beams has been observed. A relatively large two-beam coupling net gain coefficient and a four-wave mixing diffraction efficiency have been obtained. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118753

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We report small-signal modulation bandwidth and differential gain measurements of a single-layer self-organizedIn0.4Ga0.6As/GaAsquantum dot laser grown by molecular beam epitaxy. The 3 dB bandwidth of single-mode ridge waveguide lasers was measured to be 7.5 GHz at 100 mA under pulsed measurements, demonstrating the possibility of high speed operation of these devices. The differential gain was measured to be1.7×10−14 cm2.©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118754

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We demonstrate a vacuum-deposited organic light emitting device which emits from its top surface through a transparent indium-tin-oxide anode. This device employs a novel protective cap layer which prevents damage to the organic layers during sputter deposition of the anode, while also improving hole injection. Mechanisms of current transport and carrier injection from the contacts are investigated. This device configuration allows for integration of organic light emitting devices withn-channel field effect transistors used in display active matrix backplanes. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119260

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The thermal conductivity of Si–Ge superlattices with superlattice periods30<L<300Å, and aSi0.85Ge0.15thin film alloy is measured using the 3&ohgr;method. The alloy film shows a conductivity comparable to bulk SiGe alloys while the superlattice samples have a thermal conductivity that is smaller than the alloy. For30<L<70Å, the thermal conductivity decreases with decreasingL; these data provide a lower limit to the interface thermal conductanceGof epitaxial Si–Ge interfaces:G> 2 × 109 W m−2 K−1at 200 K. Superlattices with relatively longer periods,L>130Å, have smaller thermal conductivities than the short-period samples. This unexpected result is attributed to a strong disruption of the lattice vibrations by extended defects produced during lattice-mismatched growth. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118755

出版商:AIP    

年代:1997

数据来源: AIP