IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 50, NO. 3, MARCH 2002
Peter H. Siegel
, Fellow, IEEE
Terahertz technology applications, sensors, and
sources are briefly reviewed. Emphasis is placed on the less
familiar components, instruments, or subsystems. Science drivers,
some historic background, and future trends are also discussed.
Applications, submillimeter, technology, THz.
HESE DAYS, it is not possible to do justice to an entire
field or give sufficient credit to all its deserving technical
innovators in one short paper, even in a relatively narrow area of
development like terahertz technology. If this were the case, we
and Techniques Society (IEEE MTT-S), through its journals and
sponsored conferences, has played a major role in defining, dis-
nology since the society’s inception a half-century ago. During
the course of this paper, we look back to the infancy of modern
terahertz technology, beginning where Wiltse so ably left off in
1984 , pass through early childhood, and end up at adoles-
cence. The field is perched on adulthood and perhaps, in another
quarter-century, a more complete history can be written, hope-
fully by someone reading this paper today.
The first occurrence of the term
TRANSACTIONS is attributed to Fleming  in 1974, where the
term was used to describe the spectral line frequency coverage
of a Michelson interferometer. A year earlier, Kerecman  ap-
plied terahertz to the frequency coverage of point contact diode
detectors in an IEEE MTT-S conference digest paper. Ashley
and Palka  used the designation to refer to the resonant
frequency of a water laser in the same digest. Spectroscopists
had much earlier coined the term for emission frequencies
that fell below the far infrared (IR).
broadly applied to submillimeter-wave energy that fills the
Manuscript received August 21, 2001. This work was supported by the Cali-
fornia Institute of Technology Jet Propulsion Laboratory under a contract with
the National Aeronautics and Space Administration.
The author is with the Submillimeter Wave Advanced Technology Group, Jet
Propulsion Laboratory, Pasadena, CA 91109-8099 USA.
Publisher Item Identifier S 0018-9480(02)01958-0.
Oxford English Dictionary
dates the term “terahertz” back to at least
1970 where it was used to describe the frequency range of an HeNe laser. In
1947, the International Telecommunications Union designated the highest offi-
cial radio frequency bands [extremely high frequency (EHF)] as bands 12–14,
300 kMc–300 MMc (1 MMc
wavelength range between 1000–100