Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Physics
Intersubband Lasing Lifetimes Of Sige/Si And Gaas/Algaas Multiple Quantum Well Structures, Greg Sun, L. Friedman, Richard A. Soref
Intersubband Lasing Lifetimes Of Sige/Si And Gaas/Algaas Multiple Quantum Well Structures, Greg Sun, L. Friedman, Richard A. Soref
Physics Faculty Publications
The feasibility of population inversion is studied for the SiGe/Si system and compared with that of GaAs/AlGaAs. Because of the absence of strong polar optical phonon scattering in SiGe/Si, the lifetime difference of the upper and lower lasing levels, to which the population inversion and laser gain are proportional, is consistently an order of magnitude larger than that of GaAs/AlGaAs; nor does it show the sudden drop to zero or negative values when the lasing energy exceeds the optical phonon energy. Both systems studied are superlattices, each period of which consists of three coupled quantum wells and barriers.
Optical Pulse Compression In A Cholesteric Liquid Crystal, D. N. Ghosh Roy, D.V.G.L.N. Rao, H. Bronk
Optical Pulse Compression In A Cholesteric Liquid Crystal, D. N. Ghosh Roy, D.V.G.L.N. Rao, H. Bronk
Physics Faculty Publications
A 20‐ns laser pulse is compressed to nearly 2.5 ns in a 10‐cm‐long sample of liquid‐crystal cholesteryl oleate in the isotropic phase. Pulse compression in a length as short as only 5 cm has been observed. A semiquantitative explanation is given in terms of stimulated Brillouin scattering.