Chemical mapping at atomic-column resolution by energy-dispersive x-ray spectroscopy in a spherical aberration-corrected scanning transmission electron microscope (STEM) has been demonstrated for the 1.47-\AA{} dumbbell structure in InGaAs. The structural imaging and the chemical information in the two-dimensional map are directly correlated. Comparisons with the other existing mapping techniques of STEM in conjunction with electron energy-loss spectroscopy were discussed from aspects of ionization interactions.

Room temperature spasing of surface plasmon polaritons at 1.46 μm wavelength has been demonstrated by sandwiching a gold-film plasmonic waveguide between optically pumped InGaAs quantum-well gain media. The spaser exhibits gain narrowing, the expected transverse-magnetic polarization, and mirror feedback provided by cleaved facets in a 1-mm long cavity fabricated with a flip-chip approach. The 1.06-μm pump-threshold of ~60 kW/cm² is in good agreement with calculations. The architecture is readily adaptable to all-electrical operation on an integrated microchip.

We report on room-temperature continuous-wave (CW) operation of lambda~8.2 mum quantum cascade lasers grown by metal-organic chemical vapor deposition without lateral regrowth. The lasers have been processed as double-channel ridge waveguides with thick electroplated gold. CW output power of 5.3 mW is measured at 300 K with a threshold current density of 2.63 kA/cm². The measured gain at room temperature is close to the theoretical design, which enables the lasers to overcome the relatively high waveguide loss

We describe the fabrication and performance of the first integrated heterodyne receiver capable of actual heterodyne data reception. Integrating a continuously tunable 1.5 μm MQW-DBR laser with a single-mode directional coupler/switch and zero-bias MQW waveguide photodetectors, we have achieved error-free reception of FSK-modulated pseudorandom digital code at 105 Mbit/s.