Review of Terahertz Technology Readiness Assessment and Applications

Technological progress in Terahertz (THz) instrumentation in recent years has produced commercial THz systems with excellent performance, smaller footprint, easier to use operation and more reliable than their homemade laboratory predecessors. Form factor, weight, and data rate are, perhaps, the parameters that have shown the highest improvements in recent years. These parameters also have a major impact on practical application outside the laboratory environment. However, gaps still exists between proof of concepts demonstrated in the laboratory and application requirements in a real environment. The readiness of a technology can be assessed using the Technology Readiness Level (TRL) criterion, which considers nine readiness levels starting from basic concepts at TRL=1 up to full deployment at TRL=9. Applications of THz technology in spectroscopic characterization score high in TRL (7-9) because most of the progress of THz technology has been mainly focused in developing THz instrumentation for spectroscopy. Applications of THz for non-destructive evaluation applications score lower (TRL 5-6) due to higher requirements in terms of performance, especially data rate and form factor in imaging applications. Applications in the medical field have been studied with promising results but they are still in early stages of development, thus, TRL is low (1-4). The progress in THz technology is generating systems with better performance (faster acquisition rates, higher signal-to-noise ratio, bandwidth), broader availability of form factors and configurations, and tighter integration with particular applications. This progress will reduce the gap between the capabilities of the technology and the high-demanding requirements of applications in environments such as quality control and in-line production control in the manufacturing industry.