摘要:

We have studied the wet thermal oxidation ofIn0.52Al0.48Asand its potential application in current and optical confinement in vertical cavity surface emitting lasers (VCSELs). Two types of InP-based heterostructures were used to study the effect of adjacent layer compositions on the lateral oxidation behavior of the InAlAs. It was found that the oxidation ofIn0.52Al0.48Aswith InP adjacent layers, compared withIn0.53Ga0.47Asadjacent layers, proceeded faster, more uniformly and with minimal degradation of the surrounding layers making it ideal for optoelectronic applications. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121443

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

We present high peak-pulsed coherent power results from large-aperture, 1.55 &mgr;m antiguided laser arrays. The InP-based devices have a compressively strained InGaAsP double-quantum-well active region and are fabricated by two-step self-aligned metalorganic chemical vapor deposition. We have obtained 2.5 W front-facet peak power in a 2.6° wide beam [6×diffractionlimit (D.L.)], with 1.2 W in the central lobe, from 40-element, 250 &mgr;m aperture devices. The width of the central lobe remains constant from 4 to15×threshold.Devices with improved temperature characteristics and of geometry closer to the resonance condition provide 1 W peak power in a beam 1.2° wide(2.7×D.L.),with 61&percent; of the energy in the central lobe; and 1.75 W peak power in a 1.5° wide beam(3.5×D.L.)at heatsink temperatures between 15 and 45 °C. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120667

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

We observed laser emission in whispering gallery modes using a microring composed of a semiconducting polymer poly[2,5-bis-(2′-ethylhexyloxy)-p-phenylenevinylene coated on an etched fiber under transient and quasisteady-state pumping conditions. The threshold for laser oscillation was 1mJ/cm2(0.1MW/cm2)and 30&mgr;J/cm2(300MW/cm2)for nanosecond and femtosecond excitation, respectively. The laser output showed superlinear dependence on the excitation energy above the threshold. The demonstration of lasing under quasisteady-state pumping shows the possibility to develop electrically pumped polymer lasers. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120668

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Lasing at 460, 485, and 510 nm is demonstrated in optically pumped, vacuum-deposited amorphous thin films of a carbazole derivative doped with Coumarin 47, perylene, and Coumarin 30, respectively. Efficient, nonradiative Fo¨rster energy transfer between host and dopant organic molecules results in low lasing thresholds(5 &mgr;J/cm2),high differential quantum efficiencies (15&percent;), high peak output powers (20 W), and long operational lifetimes(>105pulses at 100 times the threshold power). ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120669

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

An optical parametric amplifier generating as short as 14 fs pulses in a visible region has been constructed in a noncollinear phase-matching configuration. The group-velocity matching between the signal and idler enormously broadens the gain bandwidth up to2000 cm−1,which is mainly limited by the chirp of the seed pulses. Pulses shorter than 20 fs are tunable from 550 to 690 nm by scanning the delay-line of the pump beam. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120670

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Four-wave mixing experiments in a low-birefringence optical fiber reveal an unexpected sudden increase of the conversion efficiency as the signal power crosses a threshold value. In this regime, peak frequency conversion is achieved outside the small-signal parametric gain spectrum. A nonlinear model of wave mixing fits the measured data well. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120671

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Electro-optic modulation has been demonstrated using single crystal film of an organic electro-optic material, [N-(4-nitrophenyl)-L-prolinol] (NPP), placed in a Fabry–Perot cavity. The transverse geometry was used for electro-optic modulation. The cavity used had a finesse of about 50. The modulation depth achieved was about 0.7&percent; for a low ac field of 0.5 V/&mgr;m applied along the charge-transfer (polar) axis on the film. The results are promising for applications of such films in high speed optical signal processing. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120672

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

An InP/In0.53Ga0.47As distributed absorbing Bragg reflector is investigated by reflectance and group-delay-time spectroscopy. The measured reflectance is suppressed and shows a minimum at the low-wavelength side of the high-reflectance band. This suppression of reflectance is due to an enhancement of optical absorption. The enhancement of optical absorption originates from an increase in the overlap of the optical field with the absorbing InGaAs layers since an intense optical field is confined near the surface in the spectral range of the enhancement. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120673

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The optical and physical properties of a low-voltage phosphor,SrGa2S4:Eu2+,are reviewed. This phosphor has excellent chromaticity and high luminous efficiency at excitation voltages<3 kVand at high drive current(∼100 &mgr;A/cm2).At high current densities this phosphor was found to have superior saturation properties compared to current phosphors. This is attributed to the fast decay time of this phosphor, which is expected to enhance its resistance to saturation. Recent studies show that this phosphor has good maintenance properties. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120674

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The photosensitivity of the photosurface deposition (PSD) effect and the durability in air ofAgx(Ge0.3S0.7)100−xfilms(40⩽x⩽83)with thicknesses of 50–700 nm have been studied. Films of 60–65 at. &percent; Ag and 200–300 nm thick were found to be optimal for applications in optical recording devices. Crystallized samples have been examined to obtain structural information on the Ag-rich films. It is suggested that excessAg+ions, which contribute to the PSD, exist in a disorderedAg8GeS6phase of the Ag-rich films. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120706

出版商:AIP    

年代:1998

数据来源: AIP