Coupling Optical Phonons to Free Space Photons: A Feasibility Study
Abstract
The goal of this program is to 1) demonstrate strong coupling of far-infrared radiation to polar semiconductor material at the material s longitudinal optical (LO) phonon energy, 2) investigate the optical generation of non-equilibrium phonon populations in the material, and 3) investigate the coupling of non-equilibrium LO phonons to optical modes in structures. Each of the aforementioned tasks lead towards the long term goal of developing an entirely new type of semiconductor device based on opto-phononic-electronic effects. The research effort s long-term goal is to develop an entirely new technology for generating and controlling far-IR (THz) radiation leveraging the interaction between the radiation photons, plasmon/phonon polariton modes, and non-equilibrium bulk phonons. This STIR effort will center on the feasibility of interaction process itself. First non-equilibrium populations of LO phonons will be generated optically (later electronically). Electrons in polar materials couple strongly to LO phonons (a key aspect of the design of quantum cascade lasers), allowing rapid transfer of electron populations between energy states separated by an LO phonon energy. Second the non-equilibrium phonons will be coupled to optical/phononic surface modes at the LO phonon energy. Bulk LO phonons do not couple to surface modes directly at the LO phonon energy, so leaky mode surface structures will be engineered for leaky modes at the LO phonon energy. Finally the surfaces will be fabricated to engineer meta-structures that efficiently couple the surface modes to free space photons. Phonon dynamics will be observed by Raman spectroscopy.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1610417
Entities
People
- Daniel Wasserman
Organizations
- Army Contracting Command
- United States Army
- University of Texas at Austin