"T-rays" will make X-rays obsolete!
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"The highlight of our results is observations of interference of magnetoplasmons. By tiny changes in the applied magnetic field or temperature, we can make plasma waves amplify or cancel each other. This makes the whole sample either completely opaque or transparent to the incident THz radiation."
"Using THz cameras, we could detect weapons or drugs concealed on a human body, or look inside envelopes and boxes," he says. There are many other applications for THz radiation, including material studies, chemistry, biology and medicine." link
Ref.: Interference-induced terahertz transparency in a semiconductor magneto-plasma. 2009. X. Wang, et al. Nature Physics.
Abstract: Maximum modulation of light transmission occurs when an opaque medium is suddenly made transparent. This phenomenon occurs in atomic and molecular gases through different mechanisms, whereas much room remains for further studies in solids. A plasma is an illustrative system showing opacity for low-frequency light, and light–plasma interaction theory provides a universal framework to describe diverse phenomena including radiation in space plasmas, diagnostics of laboratory plasmas and collective excitations in condensed matter. However, induced transparency in plasmas remains relatively unexplored. Here, we use coherent terahertz magneto-spectroscopy to reveal a thermally and magnetically induced transparency in a semiconductor plasma. A sudden appearance and disappearance of transmission through electron-doped InSb is observed over narrow temperature and magnetic field ranges, owing to coherent interference between left- and right-circularly polarized terahertz eigenmodes. Excellent agreement with theory reveals long-lived coherence of magneto-plasmons and demonstrates the importance of coherent interference in the terahertz regime.
