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 develop a new photorefractive electro-optical detection (PREOD)-based terahertz imaging system. This proposed device is based on a strong nonlinear optical effect in doped liquid crystal to coherently convert the terahertz field into a visible two-dimensional modulation of light intensity in real time with a response time in milliseconds and ~100 pixels per inch spatial resolution. The system produces ~1.0 mW/cm^2 sensitivity to terahertz waves producing 20% visible contrast. Use of currently available commercial low power terahertz source in the PREOD design will help 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. The miniaturized low-cost system design is frequency-independent, and has a wide bandwidth. In Phase I POC will demonstrate the feasibility of PREOD by assembling and testing a proof-of-concept prototype. In Phase II POC plans to develop a fully functional optimized terahertz imaging prototype operating at video frame rates for security applications.