Tunable High Pulse Energy Ultrafast Laser

Abstract

In this final report we discuss the acquisition and set up of the newly acquired high power ultrafast laser system and outline our research plans using the system. The first research area covers coherent acoustic phonon (CAP) spectroscopy of 4H silicon carbide (SiC) crystals. We will expand our present work on SiC to examine how an ion implantation process modifies the acousto-optical structure. The emphasis of our research remains on phenomena and processes far from equilibrium. In the second research project we intend to study transient and permanent material modification at a specified depth in semiconductors caused by a spike of localized, high density excited carriers due to coupling between photons and coherent acoustic phonons. These studies are based on the recognition that the semiconductor band gap is transiently narrowed by the CAP wave allowing localized electronic excitation at a desired depth by properly timed laser pulses of appropriate energies. In the third area of our research, we plan to explore and develop low-temperature diamond growth process assisted by ultrafast, high-power laser pulses. Our preliminary results are very promising and show that the pretreatment of substrates with ultrafast laser radiation improves the diamond growth significantly.

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Document Details

Document Type
Technical Report
Publication Date
Nov 16, 2015
Accession Number
AD1008616

Entities

People

  • Norman H. Tolk

Organizations

  • Vanderbilt University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Band Gaps
  • Ceramic Materials
  • Compound Semiconductors
  • Crystal Lattice Vibrations
  • Energy Bands
  • Films
  • Implantation
  • Ions
  • Laser Pulses
  • Low Temperature
  • Materials
  • Phonons
  • Semiconductors
  • Silicon
  • Silicon Carbide
  • Spectroscopy
  • Waves

Fields of Study

  • Physics

Readers

  • Optical Physics and Photonics.
  • Semiconductor Device Technology
  • Systems Analysis and Design

Technology Areas

  • Directed Energy
  • Microelectronics
  • Microelectronics - Graphene