The effects of Si nanocluster (Si-nc) size on the energy transfer rate to Er ions were investigated through studies made on appropriate configurations of mutilayers (MLs) consisting in about 20 periods of Er-doped Si-rich SiO<Subscript>2</Subscript>/SiO<Subscript>2</Subscript>. These MLs were deposited by reactive magnetron sputtering at...</subscript></subscript>

We have investigated electric field strengths in the Al<Subscript>x</Subscript>Ga<Subscript>1-x</Subscript>N layer, F<Subscript>AlGaN</Subscript>'s, of Al<Subscript>x</Subscript>Ga<Subscript>1-x</Subscript>N/GaN heterostructures with and without a GaN cap layer using photoreflectance (PR) spectroscopy. Franz-Keldysh oscillations (FKOs) from the Al<Subscript>x</Subscript>Ga<Subscript>1-x</Subscript>N layer are clearly observed in the PR spectra. It is...</subscript></subscript></subscript></subscript></subscript></subscript></subscript>

The optical properties of Bragg quantum wells are studied for exciton confinement under center-of-mass quantization. A variational model of Wannier exciton envelope function, that embodies the correct boundary conditions for center-of-mass, is adopted for calculation. The present non-adiabatic...