Single-frequency terahertz Michelson interferometer for applications in wood products

There is an ever-growing demand in the wood products industry for cost-effective and compact equipment to ensure wood quality measures and specifications are met. Recently, terahertz (THz) technology has begun to pave the way for new, non-destructive imaging techniques rather than the standard use of X-ray or microwave technology. A prototype THz Michelson interferometer operating at 0.102 THz was developed to measure the indices of refraction and absorption coefficients of maple, hemlock and birch. These measurements were compared to the Picometrix system, which uses conventional THz time-domain spectroscopy and has been implemented in an industrial setting for the real-time measurement of the density of OSB flakes. However, the cost and complexity of the Picometrix system prohibits its use for many industrial applications. The interferometer is cost-effective, compact and provides accurate data at low THz frequencies, thus providing an excellent alternative direction for new THz technology in the wood products industry. --Leaf ii.