02-12-2012, 10:22 PM
i want to learn more about terahertz technology & its applications with better understanding through ppt.
02-12-2012, 10:22 PM
i want to learn more about terahertz technology & its applications with better understanding through ppt.
03-12-2012, 11:25 AM
to get information about the topic "terahertz technology" related topic refer the link bellow
https://seminarproject.net/Thread-terahertz-technology
08-05-2013, 04:54 PM
Terahertz Technology
Terahertz.pdf (Size: 629.16 KB / Downloads: 36) Abstract 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. INTRODUCTION THESE 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 wouldnothavesuchaplethoraofjournals tosubmitto,norconferences to attend. Onething is certain, the IEEEMicrowave Theory and Techniques Society (IEEE MTT-S), through its journals and sponsored conferences, has played a major role in defining, distributinginformationon, andadvancingthe fieldofterahertz technology 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 [1], pass through early childhood, and end up at adolescence. The field is perched on adulthood and perhaps, in another quarter-century, a more complete history can be written, hopefully by someone reading this paper today. BACKGROUND The first occurrence of the term terahertz in this TRANSACTIONS is attributed to Fleming [2] in 1974, where the term was used to describe the spectral line frequency coverage of a Michelson interferometer. A year earlier, Kerecman [3] applied terahertz to the frequency coverage of point contact diode detectors in an IEEE MTT-S conference digest paper. Ashley and Palka [4] 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).1 TERAHERTZ APPLICATIONS The wavelength range from 1 mm to 100 m corresponds to an approximate photon energy between 1.2–12.4 meV or to an equivalent black body temperature between 14–140 K, well below the ambient background on Earth. A quick look at the spectral signature of an interstellar dust cloud (Fig. 2), however, explains why astronomers are so interested in terahertz sensor technology. An excellent science review can be found in Phillips and Keene [9]. Fig. 2 shows the radiated power versus wavelength for interstellar dust, light, and heavy molecules, a 30-K blackbody radiation curve, and the 2.7-K cosmic background signature. Besides the continuum, interstellar dust clouds likely emit some 40 000 individual spectral lines, only a few thousand of which have been resolved and many of these have not been identified. Much of the terahertz bands have yet to be mapped with sufficient resolution to avoid signal masking from spectral line clutter or obscuration from atmospheric absorption. TERAHERTZ COMPONENTS In this section, we highlight a few of the major component technologies that have been developed for terahertz applications. They broadly fall into two categories: sensors and sources. Space does not permit us to examine other terahertz component building blocks such as guiding structures, quasi-optics, antennas, filters, or submillimeter-wave materials. Some of these are reviewed in companion papers in this TRANSACTIONS. |
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