THz Photonics in Water and Beyond
Abstract
The region of the electromagnetic spectrum (0.3 – 10 THz), known as the THz frequency band, is a spectral window with rich scientific opportunities that is, at present, stunted by limited technology. The region shows great promise for a variety of reasons. First, many molecules have structural absorption resonances at these frequencies, making THz spectroscopy a unique tool for investigating matter. Second, the THz range constitutes the ultimate limit of operation for high-frequency electronics. Third, the oscillation period of THz waves corresponds to the timescale ofelementary chemical reactions, the weak collective excitations in solids, the relaxation time of phonons and the collision of free-carriers.We propose to investigate THz photonics in water in next three years: (I) Exploring basic science. The aim is to understand the dominating physics of THz wave generation from water due to short pulse laser excitation. Parallel to the proposed experiments, we will perform theoretical analysis, modeling, simulation. (II) Investigation of THz wave generation from a variety of liquids, and development of new devices. (III) Exploring the upper limitation of this THz wave generation in water by using unique lasers originally constructed for the laser fusion at The Laboratory of Laser Energetics, University of Rochester.Matter has four states: solid, liquid, gas, and plasma. The generation of THz wave from solids, gases, and plasmas has been well understood for decades. However, the demonstration of THz wave generation from liquid sources was conspicuously absent, especially from liquid water due to water’s infamously strong absorption characteristics in the THz regime. Liquids have a high density, close to that of solids, meaning that light over a certain area will interact with many more molecules than an equivalent cross-section of gases. This makes liquids very good candidates for the study of high-energy- density plasma.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 11, 2018
- Source ID
- FA95501810357
Entities
People
- Xi-Cheng Zhang
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Rochester