Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Engineering
Optical Investigation Of Molecular Beam Epitaxy AlXGa1-XN To Determine Material Quality, Judith L. Mcfall
Optical Investigation Of Molecular Beam Epitaxy AlXGa1-XN To Determine Material Quality, Judith L. Mcfall
Theses and Dissertations
The purpose of this research was to determine the quality of AIGaN samples with various mole fractions of aluminum doped with silicon. The samples utilized for this study were composed of an AIN buffer layer sandwiched between the sapphire substrate and AIGaN epilayer grown by molecular beam epitaxy (MBE). Cathodoluminescence (CL) and photoluminescence (PL) were employed to determine the mole fraction of aluminum in each sample. These techniques also gave insight into the material's nonuniformity, defects, and impurities. CL was run at 4 different beam energies (2,5,10, & 15 keV) with four different currents (1,10,50, & 90 µA) for the …
Optical Metrology Of Adaptive Membrane Mirrors, John W. Wagner
Optical Metrology Of Adaptive Membrane Mirrors, John W. Wagner
Theses and Dissertations
Current space-based imaging platforms are significantly constrained in both size and weight by the launch vehicle. Increased payload size and weight results in increased cost and a decrease in launch responsiveness. The USAF Scientific Advisory Board (SAB) identified "Large lightweight structures for optics and antennas" as a revolutionary primary technology to be developed for the Air Force of the 21st Century. A membrane primary mirror in a space-based imaging system has the ability to overcome current payload constraints and meet evolutionary needs of the future. The challenge of membrane optics in space is the process of implementing adaptive optics technology …