Semiconductor lasers are a key component in numerous emerging photonics-enabled technologies, including additive manufacturing, data centers for artificial intelligence, inertial navigation, optical power beaming, photon sail propulsion for interstellar probes, autonomous vehicles, rapid biomedical diagnostics, laser wakefield acceleration, fusion energy, and directed energy systems. In many of these applications, the laser is the most expensive, power-hungry, and failure-prone component.

The growing energy footprint of Al data centers has stressed local power grids and raised concerns about water stress, air pollution, and derailing climate progress. Analyzing this sector's impacts has proven challenging, given its fast expansion, the rapid evolution of Al hardware, software, and applications, and a pervasive lack of data for accurate energy models.

Computing accelerators, such as GPUs, enhance performance for tasks like high-resolution gaming and Al computations, while specialized accelerators in mobile devices prioritize energy efficiency. Designing these accelerators is complex, as it involves identifying computational tasks best suited for acceleration and optimizing performance and efficiency.

GaAs/InP and related alloys, and Ill-nitrides are used for most high-performance device applications except CMOS logic. Optoeletronics, high frequency (RF to THz) and power electronics are dominated by III-V compound semiconductors. We will discuss various factors of nature, nurture, and culture leading to today's landscape.

Concern over CO2 production has renewed demand for research into low-carbon solutions for the reduction and separation of metals from ore. Overlooked in the focus on low-carbon extractive metallurgy are the subsequent processing steps necessary to melt, alloy, and refine metallurgical ingots from feedstock. Changes in ore-body composition, redesigned extraction processes that yield unique impurity challenges, and tightening application-driven demands on microstructure and atomic segregation all present technical challenges for the secondary remelting and refining industry.

Microwave signals with low phase and timing noise are critical for multiple fields of wide scientific, technological, and societal impact. This includes the areas of precision timekeeping, navigation, communications and radar-based sensing. Conventional high-performance electrical oscillators rely on a resonator to achieve low-phase noise performance; however, the quality factor of the resonator limits the purity of the signal generated by these oscillators. 

J. Mijin Cha is an assistant professor of environmental studies at UC Santa Cruz.

She is also a fellow at Cornell University's Climate Jobs Institute, on the advisory board of the UCSC Center for Labor and Community, and a fellow at the Climate and Community Institute. Her research looks at the intersection of inequality and the climate crisis and how to advance a "just transition," where the energy transition is leveraged to advance a more just future. Dr. Cha is on the board of Greenpeace USA Fund and a member of the California Bar.

Increasing shares of wind and solar generation and rising electricity demand introduce uncertainty in power system operations. Improving short-term day-ahead forecasts of renewable energy generation and demand is critical for system operators to reduce the risk of forecasting errors, coordinate operations of the electricity market, and minimize the cost of maintaining the power system reliability. In this seminar, we will introduce the concepts of power systems markets.

Join us for Gauchos in Tech 3.

Addressing climate change is a major challenge, but many people struggle to understand how their energy use translates into CO2 emissions. Part of the issue is the use of varied energy units—Calories for food, gallons for gasoline, and kilowatt-hours for electricity—making comparisons difficult.