Terahertz (THz) Technology: An Introduction and Research Update

The last gap in the spectrum was bridged in 1923, when Ernest Nichols and J.D. Tear finally completed their efforts to observe radiation in the THz range. Their work was a systematic approach, both upwards in frequency from the microwave region and downward from the infrared region. Before this more-or-less official conclusion of the search, there were many significant contributions to THz-range understanding. Perhaps the most important was part of the scientific community’s effort to characterize blackbody radiation versus temperature. In 1900, in Germany, Rubens and Kurlbaum applied earlier work Rubens had done in collaboration with Nichols, resulting in accurate experimental data at longer wavelengths than had been previously observed. Max Planck wrote the equation that would become Planck’s Radiation Law on the same day that Rubens showed him those results.