Monolithic InP-based grating spectrometer for wavelength-division multiplexed systems at 1.5 mu m

A monolithic InP-based grating spectrometer for use in wavelength-division multiplexed systems at 1.5 mu m is reported. The spectrometer uses a single etched reflective focusing diffraction grating and resolves >50 channels at 1 nm spacing with a approximately 0.3 nm channel width and at least 19 dB channel isolation. Operation is essentially of the state of the input polarisation.<>     

Trends in conformity research.

Performed a content analysis of all English-language journal articles (1967–1973) studying behavioral conformity. The literature provides little indication of change from established modes of operation since the E. P. Hollander and R. H. Willis (1967) review. Little attention had been paid to role-related motives; criticisms of the ANOVA design; alternative responses to social pressure; theory construction; use of nonreactive techniques; and replication and programmatic research. Problems in conformity research are seen as general problems confronting the researcher/theorist in contemporary social psychology. (French abstract) (45 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-performance Al/sub 0.48/In/sub 0.52/As/Ga/sub 0.47/In/sub 0.53/As MSM-HEMT receiver OEIC grown by MOCVD on patterned InP substrates

Reports the first demonstration of a new long-wavelength receiver OEIC comprising an AlInAs/GaInAs MSM detector and an AlInAs/GaInAs HEMT preamplifier. The layer structure was grown by LP-MOCVD on patterned InP substrates, which allowed independent optimisation of the MSM detector and HEMT preamplifier. The MSM detector showed the lowest leakage current yet reported and the HEMT exhibited a transconductance of 260 mS/mm. An excellent receiver response to 1.7 Gbit/s NRZ signals has been obtained.<>     

High-breakdown, high-gain InAlAs/InGaAsP quantum-well HEMTs

An investigation was conducted of the DC and RF characteristics of InAlAs/InGaAsP quantum-well channel HEMTs. An extrinsic transconductance as high as 210 mS/mm was obtained for a gate length of 1.0 μm. The HEMTs showed excellent drain-source and gate-drain breakdown characteristics and a very small output conductance of less than 2 mS/mm, resulting in a very high DC voltage gain of greater than 100. The maximum available gain (MAG) was measured to be as high as 14.5 dB at 20 GHz, which corresponds to an extrapolated f_max of 105 GHz     

Cavity length and doping dependence of 1.5-μm GaInAs/GaInAsPmultiple quantum well laser characteristics

High-power, 1.5-μm, ridge-waveguide lasers with GaInAs/GaInAsP multiple-quantum-well active layers are discussed. For 1-mm-long devices, a threshold current of 35 mA and an output power of 62 mW per facet were measured. The cavity-length and doping dependence of the threshold current, quantum efficiency, and resonant frequency were investigated experimentally. With heavy Zn doping in the barrier layers, an increase in differential gain by a factor of 1.8 was observed     

Treatment of multiple myeloma with high-dose chemotherapy and transplantation of autologous hematopoietic stem cells and subsequent maintenance therapy with interferon alfa-2b or interferon alfa 2b and dexamethasone. Report of the ongoing study of the "4W" Czech Myeloma Group

We report our results with high-dose chemotherapy in previously untreated multiple myeloma patients (4 courses of VAD chemotherapy, collection of PBSC after priming with cyclophosphamide, 5 g/m2, high-dose chemotherapy with melphalan, 200 mg/m2). Second transplantation was indicated only for patients who did not achieve remission after the first high-dose therapy (paraprotein lower than 25% of the pretreatment value). For the second transplantation melphalan (200 mg/m2) with methylprednisolone (1.5 g for 5 days) were used as conditioning regimen. After high-dose therapy all patients were randomized into two arms of maintenance therapy: interferon alpha-2b or sequential maintenance therapy (interferon alpha-2b for 3 months followed after 4 week pause by 40 mg of dexamethasone days 1-4, 10-13 and 20-23. The administration of interferon alpha was resumed four weeks after the last dexamethasone for next three months. The maintenance therapy continued for 48 months or until the progression. Fifty-five patients were enrolled in the study from January 1996 to August 1997. Thirty-five patients have undergone the first transplantation and 57% of them reached complete remission. There were 10% of non-responders after the first high-dose regimen. The mean time to reach white blood cell count above 1 x 10(9)/L after the application of high dose melphalan and platelets more than 50 x 10(9)/L were 12.2 (range 6-16 days) and 12.4 (range 0-25 days), respectively. Grade 4 mucositis according to SWOG classification requiring total parenteral nutrition was presented in 40% of the patients. The mean number of 1 unit of platelets and 2 units of packed red blood cells transfusions were given within the posttransplant period. Early transplant related mortality was 3%. This paper describes the response and tolerance of each particular step of therapy. The follow-up has been too short to evaluate event-free and overall survivals.     

High-performance InP reflection-grating wavelength multiplexer

A high-performance InP reflection-grating wavelength multiplexer for the 1530-1560 EDFA fibre band is reported. The 8 channel 3.6 nm-spacing devices operated with 30-35 dB channel isolation, <0.04 wavelength precision, and <10 dB on-chip loss. Although realised with 3.6 nm spacings, the multiplexer may be adapted for channels as close as 0.5 nm     

Use of multimode interference couplers to broaden the passband of wavelength-dispersive integrated WDM filters

We describe how multimode interference couplers (MMI) may be used to broaden and flatten the passband of integrated wavelength-dispersive filters. We discuss the approach and demonstrate its effectiveness with a passband-broadened InP arrayed waveguide filter operating at 1.5 /spl mu/m.     

Low threshold current density 1.5 mu m GaInAs/AlGaInAs graded-index separate-confinement-heterostructure quantum well laser diodes grown by metal organic chemical vapour deposition

A low threshold current density of 640 A/cm/sup 2/ was obtained in a 1.5 Gmm GaInAs/AlGaInAs multiple quantum well laser diode, grown by metal organic chemical vapour deposition, with continuously graded-index separate-confinement heterostructure. An internal waveguide loss of 14 cm/sup -1/ and internal quantum efficiency of 59% were obtained, which are comparable to those of GaInAs/GaInAsP quantum well laser diodes.<>     

Breakdown of phonon glass paradigm in La- and Ce-filled Fe4Sb12 skutterudites

The material class of skutterudites is believed to have strong potential for thermoelectric application due to the very low thermal conductivity of the filled structures. It is generally assumed that the atoms filling the skutterudite cages act as 'rattlers' and essentially induce a disordered lattice dynamics referred to as 'phonon glass'. Here, we present neutron spectroscopy experiments and ab initio computational work on phonons in LaFe(4)Sb(12) and CeFe(4)Sb(12). Our results give unequivocal evidence of essentially temperature-independent lattice dynamics with well-defined phase relations between guest and host dynamics, indicative of a quasi-harmonic coupling between the guests and the host lattice. These conclusions are in disagreement with the 'phonon glass' paradigm based on individual 'rattling' of the guest atoms. These findings should have an essential impact on the design and improvement of thermoelectric materials and on the development of microscopic models needed for these efforts.