Portable Terahertz Imaging System

To address the Army need for a cost-effective, real-time, high-resolution portable terahertz (THz) imaging system, Physical Optics Corporation (POC) proposes to complete the development of the new PhotoRefractive Electro-Optical Detection (PREOD)-based terahertz imaging system (PREOD-THz) proven feasible in Phase I. The Phase II PREOD-THz will coherently convert the terahertz field into a visible two-dimensional image for immediate view in milliseconds and with spatial resolution of ~100 pixels per inch. The system produces ~1.0 mW/cm^2 sensitivity to terahertz waves for 20% visible contrast. The sensitivity allows the use of a currently available commercial low-power terahertz source, helping achieve sensitive detection with a signal-to-noise ratio of ~1000 to produce a two-dimensional snapshot of a terahertz image instead of point-by-point detection, which greatly alleviates the current problem of long image acquisition time. The miniaturized low-cost system design is frequency-independent, and has a wide bandwidth. POC has demonstrated the PREOD principle by simulation and by fabricating a proof-of-concept prototype, demonstrating terahertz sensitivity and real-time detection. In Phase II POC will optimize the design and component performance, and develop a fully functional engineering prototype meeting Army requirements. PREOD-THz will represent a new portable terahertz imaging system operating at video frame rates for security applications.