Advanced THz Materials for Nondestructive Evaluation (NDE)

In this Phase I project, we will demonstrate the improvement of the time-domain-terahertz (TD-THz) transmitter output power of low temperature grown indium gallium arsenide (LT-InGaAs) based epitaxial layer structures excited by the 1060 nm lasers, such as that employed in the T-RayTM 4000 TD-THz instrumentation system. Prior to this SBIR proposal, Picometrix has developed and commercialized 1060 nm driven LT-InGaAs photoconductive material with performance equivalent to traditional 800 nm driven low temperature grown gallium arsenide (LT-GaAs). The goal of this Phase I SBIR project will be to increase the electric field within the THz transmitting antenna at least 10 times over Picometrix’s current LT-InGaAs (or LT-GaAs) antenna by developing an enhanced LT-InGaAs photoconductive material. This emphasis on epitaxial growth and microfabrication during the first phase will provide the basis for a high-sensitivity THz transceiver that will make stand-off non-destructive evaluation (NDE) imaging possible during Phase II. BENEFIT: In phase II we will package the enhanced “high performance” LT-InGaAs transmitter materials into the Picometrix’s standard telecommunications style miniature fiber pigtailed modules. These modules will provide greater than 10 times the electric field (and thereby a 10x increase in signal to noise) over the current generation of LT-InGaAs modules (or LT-GaAs modules). A Phase II prototype NDE stand-off imaging monostatic reflection TD-THz transceiver with 3-5 meter stand-off will be constructed, utilizing the new high performance modules. This will allow inspection of aircraft from the ground, without having to bring the instrument up near to the aircraft skin.