Aluminum-free strained-layer lasers emitting at 1.14 μm on low-composition InGaAs:n substrates by metalorganic chemical vapor deposition
Broad-area (W=150 /spl mu/m) single-quantum-well (SQW) lasers have been successfully fabricated on n-type In/sub 0.03/Ga/sub 0.97/As substrates without incorporating aluminum-containing alloys. The strained-layer InGaP-GaAs-InGaAs heterostructure was grown by atmospheric pressure metalorganic chemical vapor deposition. Due to both the increased substrate lattice constant and the partial strain compensation supplied by the tensile-strained GaAs optical guiding layers, a peak emission wavelength of 1.1403 /spl mu/m is obtained for a 1-mm cavity length.
Strained-layer InGaAs-GaAs-InGaP buried-heterostructure quantum-well lasers on a low-composition InGaAs substrate by selective-area MOCVD
Aluminum-free buried-heterostructure quantum-well lasers have been successfully fabricated on low-composition InGaAs substrates. Selective-area metalorganic chemical vapor deposition (MOCVD) was utilized to investigate a variety of InGaAs quantum wells with a wide range of composition and thickness. Compressively strained quantum wells can be deposited thicker on substrates of InGaAs than GaAs before the generation of misfit dislocations. These deeper potential wells enable laser diodes with longer wavelengths (1.1504 /spl mu/m) than GaAs-based emitters and higher characteristic temperatures (145 K) than InP-based devices.
The measuriment of ferromagnets magnetic characteristics using Labview software
The digital method of measurement and registration of dynamic loops hysteresis family of magneto-soft materials where, along with known analogues from electro-technical steel, magnetic materials with considerably smaller specific magnetic losses such as amorphous alloys on the basis of iron, is offered. Tests of magnetic properties of materials are carried out on the base of the hardware-software measuring complex in which along with the standard established electric equipment and USB oscillograph for realization of a digital method, the software for the personal computer developed in the environment of visual programming of Borland Delphi 7.0, connected through the ActieveX technology with the Labview 7.0 environment, is applied. The software allows carrying out input of basic data concerning geometry of prototypes of cores from magnetic materials and numbers of rounds of the magnetizing and measuring windings located on their surface. Experimental data on voltage at measuring winding terminals are processed by means of the virtual integrator in a Labview package. The developed software provides the possibility of saving the obtained hysteresis loop in the form of a text file, and creation of the hysteresis loops family on the virtual oscillograph screen.