DURIP: Synchronized Dual Femtosecond Laser for Terahertz Spectroscopy at Nanoscale
Abstract
DURIP: Synchronized Dual Femtosecond Laser for Terahertz Spectroscopy at Nanoscale PI: Mona Jarrahi, Associate Professor of Electrical Engineering University of California Los Angeles Program Manager: Dr. Paul Maki, Office of Naval Research (312) Abstract A novel optical-pump terahertz-probe spectroscopy technique has been recently presented by Terahertz Electronics Laboratory at UCLA, which allows direct monitoring of ultrafast carrier dynamics in nanoscale semiconductors with relation to the applied electric field, while accounting for the quantum phenomena and interface effects, for the first time. This unique capability has become possible by a new class of multi-spectral plasmonic nanostructures integrated with semiconductors, which enable efficient interaction of optical and terahertz beams with semiconductors at nanoscale in a time-resolved optical-pump terahertz-probe measurement system. By using this powerful technique, the Terahertz Electronics Laboratory has been conducting research on ballistic and quasi ballistic carrier transport dynamics at nanoscale and has gained valuable knowledge on the fundamental physical limitations of nano-electronic and nano-photonic devices. However, a major limitation in this study has been the relatively long spectral scanning times, which prevents monitoring the phonon scattering dynamics and thermal effects while studying the ballistic and quasi-ballistic carrier transport dynamics in semiconductor nanostructures. The relatively long spectral scanning times are due to the requirement for varying the time-delay between the optical pump and probe pulses in a time-domain spectroscopy system. Through this DURIP proposal, we request funds for purchasing a synchronized phase-modulated dual femtosecond laser package, which eliminates the need for a variable time-delay between the pump and probe optical pulses in a time-domain spectroscopy setup. It allows capturing the spectroscopic data in one snap-shot, which enables monitoring the phonon scattering dynamics and thermal effects while studying the ballistic and quasi-ballistic carrier transport dynamics in semiconductor nanostructures. This new capability would fill an important knowledge gap, both from a fundamental physics perspective and for utilizing unique functionalities of nanoelectronic and nanophotonic devices. It enables fundamental discoveries on the interaction of phonons, electrons, holes, excitons and semiconductor lattice. In particular, understanding the dynamics of ballistic and quasi-ballistic carrier energy dissipation while interacting with semiconductor interfaces, defects and scattering centers helps optimizing power consumption and efficiency of nano-scale photovoltaics, nanoelectronic and nanophotonic devices integrated on a single chip. It also offers a valuable understanding of the fundamental physical limitations of ultrafast operation of nanoscale devices and a more realistic prediction for the ultimate extent of transistor scaling roadmap in the future.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512842
Entities
People
- Mona Jarrahi
Organizations
- Office of Naval Research
- United States Navy
- University of California, Los Angeles