6,551 research outputs found
Terahertz Waveguiding in Silicon-Core Fibers
We propose the use of a silicon-core optical fiber for terahertz (THz)
waveguide applications. Finite-difference time-domain simulations have been
performed based on a cylindrical waveguide with a silicon core and silica
cladding. High-resistivity silicon has a flat dispersion over a 0.1 - 3 THz
range, making it viable for propagation of tunable narrowband CW THz and
possibly broadband picosecond pules of THz radiation. Simulations show the
propagation dynamics and the integrated intensity, from which transverse mode
profiles and absorption lengths are extraced. It is found that for 140 - 250
micron core diameters the mode is primarily confined to the core, such that the
overall absorbance is only slightly less than in bulk polycrystalline silicon.Comment: 6 pages, 3 figures, journal submissio
Wide Bandgap Based Devices: Design, Fabrication and Applications, Volume II
Wide bandgap (WBG) semiconductors are becoming a key enabling technology for several strategic fields, including power electronics, illumination, and sensors. This reprint collects the 23 papers covering the full spectrum of the above applications and providing contributions from the on-going research at different levels, from materials to devices and from circuits to systems
US Microelectronics Packaging Ecosystem: Challenges and Opportunities
The semiconductor industry is experiencing a significant shift from
traditional methods of shrinking devices and reducing costs. Chip designers
actively seek new technological solutions to enhance cost-effectiveness while
incorporating more features into the silicon footprint. One promising approach
is Heterogeneous Integration (HI), which involves advanced packaging techniques
to integrate independently designed and manufactured components using the most
suitable process technology. However, adopting HI introduces design and
security challenges. To enable HI, research and development of advanced
packaging is crucial. The existing research raises the possible security
threats in the advanced packaging supply chain, as most of the Outsourced
Semiconductor Assembly and Test (OSAT) facilities/vendors are offshore. To deal
with the increasing demand for semiconductors and to ensure a secure
semiconductor supply chain, there are sizable efforts from the United States
(US) government to bring semiconductor fabrication facilities onshore. However,
the US-based advanced packaging capabilities must also be ramped up to fully
realize the vision of establishing a secure, efficient, resilient semiconductor
supply chain. Our effort was motivated to identify the possible bottlenecks and
weak links in the advanced packaging supply chain based in the US.Comment: 22 pages, 8 figure
Chapter Efficient and Validated Time Domain Numerical Modeling of Semiconductor Optical Amplifiers (SOAs) and SOA-based Circuits
Artificial intelligenc
Efficient and Validated Time Domain Numerical Modeling of Semiconductor Optical Amplifiers (SOAs) and SOA-based Circuits
Semiconductor optical amplifiers (SOAs) have been extensively used in a wealth of telecom and datacom applications as a powerful building block that features large optical gain, all-optical gating function, fast response, and ease of integration with other functional semiconductor devices. As fabrication technologies are steadily maturing toward enhanced yield, SOAs are foreseen to play a pivotal role in complex photonics integrated circuits (PICs) of the near future. From a design standpoint, accurate numerical modeling of SOA devices is required toward optimizing PICs response from a system perspective, while enhanced circuit complexity calls for efficient solvers. In this book chapter, we present established experimentally validated SOA numerical modeling techniques and a gain parameterization procedure applicable to a wide range of SOA devices. Moreover, we describe multigrid concepts and implicit schemes that have been only recently presented to SOA modeling, enabling adaptive time stepping at the SOA output, with dense sampling at transient phenomena during the gain recovery and scarce sampling during the steady-state response. Overall, a holistic simulation methodology approach along with recent research trends are described, aiming to form the basis of further developments in SOA modeling
Towards an integrated perspective on fleet asset management: engineering and governance considerations
The traditional engineering perspective on asset management concentrates on the operational performance the assets. This perspective aims at managing assets through their life-cycle, from technical specification, to acquisition, operation including maintenance, and disposal. However, the engineering perspective often takes for granted organizational-level factors. For example, a focus on performance at the asset level may lead to ignore performance measures at the business unit level. The governance perspective on asset management usually concentrates on organizational factors, and measures performance in financial terms. In doing so, the governance perspective tends to ignore the engineering considerations required for optimal asset performance. These two perspectives often take each other for granted. However experience demonstrates that an exclusive focus on one or the other may lead to sub-optimal performance. For example, the two perspectives have different time frames: engineering considers the long term asset life-cycle whereas the organizational time frame is based on a yearly financial calendar. Asset fleets provide a relevant and important context to investigate the interaction between engineering and governance views on asset management as fleets have distributed system characteristics. In this project we investigate how engineering and governance perspectives can be reconciled and integrated to enable optimal asset and organizational performance in the context of asset fleets
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