Terahertz Science and Technology Trends

The recent progress in terahertz science and technology (THz-S&T) opens up a range of potential research opportunities. Historically, THz technologies were mainly used by the astronomy community for searching far-infrared radiation (cosmic background), and by the laser fusion community for the diagnostics of plasmas. Since the first demonstration of THz wave time-domain spectroscopy in the late 1980s, there has been a series of significant advances (particularly in recent years) as intense THz sources and more sensitive detectors provide new opportunities for understanding the basic science in the THz frequency range. THz radiation can penetrate through many nonpolar dielectric materials and can be used for nondestructive/noninvasive sensing and imaging of targets under nonpolar, nonmetallic covers or containers. An immediate application of THz wave technology is in nondestructive testing or inspection. Short-term applications (within three to five years) are expected in spectroscopic sensing and imaging for homeland security. Biomedical applications are expected in the long term (five to ten years). By comparing the publication record trend of THz-S&T related papers with the publication record of proxy fields (laser, microwave, Raman, and infrared), it is possible to anticipate that the number of publications in the THz-S&T arena will increase and also the impact in other research areas. We compare the publication pattern (number of papers versus time) with searching keywords in title or abstract. We found that all the publication trends share a common pattern with four periods defined by discovery, acceptance, adoption, and maturity. From this pattern trend, THz-S&T seems to be in an acceptance period. The unique properties of THz-S&T suggest that its applications will grow.