This Major Research Instrumentation (MRI) Program grant support acquisition of a millimeter wave vector network analyzer (MWVNA) tunable from 8 GHz to 1 THz and associated microwave hardware to develop a method for non-contact laser excitation and detection of ultrasonic waves in earth materials. The terahertz network analyzer will complement existing laser and ultrasonics equipment in the Physical Acoustics Laboratory in the Department of Geophysics at the Colorado School of Mines. As part of this proposal, the PI's will try to extend recent laboratory successes in imaging acoustic waves excited on the surfaces of granite and aluminum slabs via laser to field applications using higher frequency sources (100'a of GHz to 1 THz) and the acquired detection system. A method of non-contact seismology is envisioned which could have broad applications in the geosciences (e.g., imaging of highly polluted subsurface environments), archaeology, and civil and military engineering (e.g., non-contact detection of unexploded ordnance (UXO)).
