Michael James Moewe

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We report a novel high-quality (Q) factor optical resonator using a subwavelength high-contrast grating (HCG) with in-plane resonance and surface-normal emission. We show that the in-plane resonance is manifested is by a sharp, asymmetric lineshape in the surface-normal reflectivity spectrum. The simulated Q factor of the resonator is shown to be as high as(More)
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(More)
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(More)
Monolithic integration of III-V compound semiconductor devices with silicon CMOS integrated circuits has been hindered by large lattice mismatches and incompatible processing due to high III-V epitaxy temperatures. We report the first GaAs-based avalanche photodiodes (APDs) and light emitting diodes, directly grown on silicon at a very low, CMOS-compatible(More)
S. Crankshaw,1 S. Reitzenstein,3 L. C. Chuang,2 M. Moewe,2 S. Münch,3 C. Böckler,3 A. Forchel,3 and C. Chang-Hasnain1,2 1Applied Science and Technology, University of California at Berkeley, Berkeley, California 94720, USA 2Department of Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, California 94720, USA(More)
Catalyst-free GaAs nanoneedles are grown on a c-plane sapphire substrate at 400°C using MOCVD. Despite of an extremely large lattice mismatch of 46%, the nanoneedles show single wurtzite-phase and bright room-temperature photoluminescence with narrow linewidths.
We spatially resolve photoluminescence from wurtzite InGaAs/GaAs core-shell nanoneedles and characterize their nonuniform quantum well emission. Polarization measurements reveal anisotropy behavior that is reminiscent of GaN and other wurtzite materials.
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(More)
Heterogeneous integration of dissimilar single-crystalline materials, such as III-V compound on Si or sapphire, enables functionalities and performance that cannot be achieved with single material system. Yet, lattice mismatch makes growing high quality thin film on dissimilar substrates difficult. Recently high quality nanowires have been demonstrated on(More)