Quantum well structures containing single isolated quantum wells and superlattices of GaInAs/InP and GaInAsP/InP have been grown by Gas Source MBE in order to attempt to establish the limits of pre
Quantum Cascade (QC) lasers are based on inter-subband transitions in the conduction band.
Two step liquid phase epitaxy is shown to be impeded in the GaInAsP system by the difficulty of achieving uniform epitaxial wetting and highly radiative interfaces.
Double heterostructure lasers of Ga sub (x) In sub (1-x) As sub (1-y) Py lattice matched to InP and emitting at 1.55micron have been grown by chemical beam epitaxy (CBE).
Double heterostructure and separate confinement heterostructure lasers of Ga(x)In(1-x)As(1-y)P(y) lattice matched to InP and emitting at 1.5 micron have been grown by molecular beam epitaxy utili
Gallium antimonide and related compounds are promising materials for fabricating monolithic vertical cavity semiconductor lasers operating at telecommunications wavelengths.
We present maps showing the distribution of molecular gas in the Galactic center region.
Recent papers discussing positron annihilation data from the galactic center have used several incompatible definitions of "the positronium fraction".
A CCD survey of a complete sample of 42 QS0 fields shows a significant excess of detected galaxies within 30 arcsec of the QS0, even for QS0 redshifts in the range 1 - 1.5.
I review the evidence for galaxy evolution, and describe recent observations of faint field galaxies.
