Electron spin polarization induced by linearly polarized light in a (110) GaAs quantum-well waveguide.

We report an experimental demonstration of generating electron spin polarization with linearly polarized light in a (110) GaAs quantum well. A detailed frequency-domain pump-probe study shows that the dynamic nuclear spin polarization arising from the oriented electron spins results in a strong dependence of the electron spin splitting on the photon energy and intensity of the linearly polarized excitation laser.

Core-shell InGaAs/GaAs quantum well nanoneedles grown on silicon with silicon-transparent emission.

In(x)Ga(1-x)As wurtzite nanoneedles are grown without catalysts on silicon substrates with x ranging from zero to 0.15 using low-temperature metalorganic chemical vapor deposition. The nanoneedles assume a 6 degrees - 9 degrees tapered shape, have sharp 2-5 nm tips, are 4 microm in length and 600 nm wide at the base. The micro-photoluminescence peaks exhibit redshifts corresponding to their increased indium incorporation. Core-shell InGaAs/GaAs layered quantum well structures are grown which exhibit quantum confinement of carriers, and emission below the silicon bandgap.

Room temperature slow light in a quantum-well waveguide via coherent population oscillation.

We report room temperature demonstration of slow light propagation via coherent population oscillation (CPO) in a GaAs quantum well waveguide. Measurements of the group delay of an amplitude modulated signal resonant with the heavy-hole exciton transition reveal delays as long as 830 ps. The measured bandwidth, which approaches 100 MHz, is related to the lifetime of the photoexcited electron-hole (e-h) plasma as expected for CPO process.