Terahertz Spectral Imaging Using Correlation Processing

Terahertz (THz) reflection imaging has the potential to extract unique spectral signatures from various materials of interest, but these signatures can be distorted by rough surface scattering, low signal strength, and alignment errors. One method of addressing these challenges and increasing performance is to coherently combine reflection information across frequency bands. This method, called correlation processing, uses both phase and magnitude information to provide concurrent imaging and chemical mapping. This paper first shows imaging results from pressed pellets made of both lactose and high density polyethylene. It will be shown using measured THz scattered data and Monte Carlo simulations that correlation processing can correctly distinguish between materials with spectral signatures and other compounds. THz spectral surface profiling results from the pressed pellet are provided and discussed.