III-Nitride Quantum Dot and Dot-in-nanowire Light Sources: From Visible to Near-Infrared

Low threshold visible lasers are useful for a number of applications including full color mobile projectors, optical data storage, heads-up displays in automobiles, in medicine and plastic fiber communication. Lasers emitting in the blue and green are generally realized with GaN-based InGaN/GaN quantum wells (QWs) as the gain media. Self-organized quantum dots (QDs), which form by strain relaxation, offer distinct advantages over quantum wells and their emission can be extended to longer wavelengths (~ 630 nm).

From Mud to Electrode Catalysts and Conductive Nanomaterials

Dissimilatory metal-reducing bacteria (DMRB) are a class of microorganisms that inhabit many subsurface environments including marine sediments. They occupy a distinct metabolic niche wherein they can acquire energy by coupling oxidation of organic matter with reduction of insoluble oxidants such as mineral deposits. This capability requires that DMRB transfer electrons to their outer surface where electron-transfer can occur to an insoluble oxidant which is distinct from the dominant paradigm in which soluble oxidants are transported into cells for reduction during metabolism.

Integrated Photonic Technologies for On-Chip and Space Applications

Integrated photonics has the potential to greatly reduce the size, weight, and power (SWaP) while improving the performance and reliability of photonic systems. This technology has already impacted telecommunications and is expected to transform data center communications, high performance computing, microwave photonics, and sensing. This talk will describe examples of integrated photonic technologies being developed in our research group and also discuss a novel application for integrated photonics, namely, space optical communications.

Single-Step Low-Temperature Growth of High-Mobility Large-Area Graphene and the Potential Applications

Graphene, a monolayer of carbon atoms forming a two-dimensional honeycomb lattice structure, is considered a wonder material for both scientific research and technological applications since its successful isolation in 2004. As a flexible, transparent conductor with intrinsically very high electrical mobility and thermal conductivity, graphene is promising for large-area electronic devices such as touch screen displays, electrodes for photovoltaic cells, interconnects for electrical circuits, and panels for light emitting diodes.

Mixed-signal Circuit Techniques for High-linearity 50 GS/s Sampling and Pulsewidth Modulation for High-Speed Signaling

Capacity growth in communication and sensor networks suggests order of magnitude increases over the next decade. To satisfy this growth, wireless and optical network technologies will increase spectral efficiency through a combination of signal processing and device improvements. At millimeter-wave bands, high-order modulation such as quadrature-amplitude modulation (QAM) is critical for backhaul links at the expense of higher peak-to-average power ratios. Similarly, coherent optical detection techniques for QPSK in 40/100 GbE optical networks have gained industry acceptance.

Harness the Sun: America's Quest for a Solar-Powered Future

What can we expect from rooftop photovoltaic arrays on our homes, businesses, and public buildings?  What are the opportunities and challenges we face as we look to America’s brownfields – waste sites and other industrial properties – to extend solar power’s reach? And how shall we reckon with the prospects and pitfalls of building utility-scale solar plants on our farmlands and natural open spaces?

VLSI Photonic Quantum Technologies for Classical IT

Moore’s Law has set great expectations that the performance/price ratio of commercially available semiconductor devices will continue to improve exponentially at least until the end of this decade. Although the physics of nanoscale silicon transistors alone could allow these expectations to (almost) be met, the physics of the metal wires that connect these transistors places stringent limits on the performance of integrated circuits.

California’s Low Carbon Future: Energy Efficiency and Distributed Energy Resources

Southern California Edison is working to help achieve California’s ambitious carbon reduction goals by modernizing its distribution system to be flexible, adaptable and capable of two-way electrical flows to better integrate distributed energy resources – such as demand side management (Energy Efficiency/Demand Response), rooftop solar, electric vehicles and energy storage – while maintaining the reliability, safety, and power quality customers count on.

American Institute for Manufacturing Integrated Photonics: Implications for the Future

President Obama is setting up National Networks for Manufacturing Institutes and UCSB is the West Coast hub for the American Institute on Manufacturing Integrated Photonics (AIM Photonics). This Institute is focused on developing an end-to-end integrated photonics ecosystem in the U.S., including domestic foundry access, integrated design tools, automated packaging, assembly and test, and workforce development.