摘要:

Picosecond laser pulses were used to simulate current injection and generate dark defects in ZnSSe/ZnCdSe quantum well structures. The formation of the defects was monitoredinsituwith a photoluminescence microscope setup, with spatial resolution of about 1 &mgr;m. Dark defects are observed to form in the ZnCdSe quantum well, analogous to electrical injection in separate confinement heterostructure diode lasers. Transmission electron microscopy of the optically generated dislocation network gives further insight to the origin of the defect microstructure. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113676

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Single‐mode silicon on insulator photoelastic waveguides and polarizers have been investigated. It was found that waveguides induced by the photoelastic effect can be low loss (1.5 dB/cm at 1.53 &mgr;m) and can serve as polarizers as well. A polarization distinction ratio of 14 dB for both TE and TM mode has been obtained. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113677

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Organomineral crystals are engineered to combine the favorable properties of organic and inorganic materials. High gain parametric emission and amplification at telecommunications wavelengths are demonstrated in an organomineral crystal, 2‐amino‐5‐nitropyridinium‐dihydrogen phosphate. A novel angle‐noncritical type‐II phase‐matching configuration is observed in parametric emission, and parametric amplification is demonstrated at 1.5 &mgr;m. ©1995 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.113678

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Exploiting the sensitivity and the self‐aligning features of the confocal laser‐feedback technique and the convenience of superluminescent laser diodes, we developed an optical method for imaging and profiling surface microstructures with a depth resolution as great as 20 nm. The incoherent, noninterferometric nature of the technique enables fast open‐loop operation and large dynamic range. Measurements of calibrated semiconductor surface microstructures and optical ridge waveguides are demonstrated. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113679

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Carrier confinement performance by multiple quantum barriers (MQB) is demonstrated in 1.55 &mgr;m strained GaInAs/AlGaInAs multiple quantum well (MQW) lasers grown by molecular beam epitaxy. The strained MQW lasers with MQB atp‐side optical confinement layer show larger characteristic temperature and slope efficiency at high temperature than those without MQB. It is also shown that the MQW lasers with MQB have less spontaneous emission from the optical confinement layer than the lasers without MQB. As another important result, it is demonstrated for the first time that the MQW lasers with MQB have less dependency of theKfactor on the temperature than the lasers without MQB. These results further verify the effective carrier confinement performance of GaInAs/AlInAs MQB structure. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113680

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The effect of nonuniform current injection on the frequency chirp of a two section distributed feedback (DFB) laser, which is under large signal modulation, is measured while the optical intensity and optical modulation depth are fixed. By adjusting the injection current distribution in the laser, the frequency chirp can be reduced since the effects of carrier density fluctuations in the two sections on the chirp partially compensate each other. The range of the injection current ratio of the two sections is found in which the chirp is at its minimum. The reduction of the frequency chirp is predicted by a computer simulation for two section DFB lasers which accounts for the longitudinal spatial hole burning. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113681

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A combination of spontaneous emission lifetime and spectral measurements is used to estimate the threshold carrier density in small diameter gain guided vertical cavity surface emitting lasers. Differential spontaneous emission lifetimes measured below threshold are extrapolated to a &tgr;th=0.4 ns at threshold. The corresponding threshold carrier density isNth=7.9×1018cm−3. The measured carrier densities are used to calculate spontaneous emission spectra. These are in agreement with the edge emission spectra obtained on cleaved laser chips. For the measured carrier density, we estimate the threshold gain at the emission wavelength ofg=1640 cm−1. ©1995 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.113682

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The 248 nm UV photosensitivity of H2loaded optical fibers is shown to be significantly enhanced by increasing the temperature during the UV exposure. Heating to 250–400 °C resulted in dramatic UV reaction rate increases in GeO2doped fibers. Increasing the core temperature during 248 nm irradiation caused P2O5doped fibers to become photosensitive. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113683

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A CdTe photoconductor array x‐ray detector was grown using molecular beam epitaxy (MBE) on a Si(100) substrate. The temporal response of the photoconductor arrays is as fast as 21 ps rise time and 38 ps full width half‐maximum (FWHM). The spatial resolution of the photoconductor was good enough to provide 75 &mgr;m FWHM using a 50 &mgr;m synchrotron x‐ray beam. A substantial number of x‐ray photons are absorbed effectively within the MBE CdTe layer as observed from the linear response up to 15 keV. These results demonstrate that MBE grown CdTe is a suitable choice of the detector materials to meet the requirements for x‐ray detectors. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113684

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The observed temperature dependence of threshold currents in InGaAs/GaAs quantum‐well ridge‐waveguide lasers is modeled. This method incorporates both experimental data and theoretical gain calculations. The results show that lateral leakage currents must be included in the ridge‐waveguide laser models. Based on the same model, the temperature‐dependent modulation characteristics for InGaAs/GaAs quantum‐well ridge‐waveguide lasers are also investigated. ©1995 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.113685

出版商:AIP    

年代:1995

数据来源: AIP