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Record-Breaking Terahertz Laser Beam

posted by Fnord666 on Tuesday January 21 2020, @02:08AM   
from the illuminating dept.

Arthur T Knackerbracket has found the following story:

Terahertz radiation is used for security checks at airports, for medical examinations and also for quality checks in industry. However, radiation in the terahertz range is extremely difficult to generate. Scientists at TU Wien have now succeeded in developing a terahertz radiation source that breaks several records: it is extremely efficient, and its spectrum is very broad—it generates different wavelengths from the entire terahertz range. This opens up the possibility of creating short radiation pulses with extremely high radiation intensity. The new terahertz technology has now been presented in the journal Nature Communications.

More information: Anastasios D. Koulouklidis et al. Observation of extremely efficient terahertz generation from mid-infrared two-color laser filaments, Nature Communications (2020). DOI: 10.1038/s41467-019-14206-x

Journal information: Nature Communications

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Original Submission

• Re:Not a laser ? Re:Not a laser ? (Score: 2) by takyon on Tuesday January 21 2020, @02:41PM (1 child)

  by takyon (881) <takyonNO@SPAMsoylentnews.org> on Tuesday January 21 2020, @02:41PM (#946338) Journal

  https://en.wikipedia.org/wiki/Laser [wikipedia.org]

  A laser differs from other sources of light in that it emits light which is coherent. Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers and lidar. Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i.e., they can emit a single color of light. Alternatively, temporal coherence can be used to produce pulses of light with a broad spectrum but durations as short as a femtosecond ("ultrashort pulses").

  Looks like spatial coherence is "required" to call it a laser, while temporal coherence seems to be optional. And the coherence quality will vary, so some lasers will scatter over a shorter distance than others, and the light emitted by a 375nm laser will not all be at exactly 375nm, etc.

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• Re:Not a laser ? (Score: 2) by nishi.b on Tuesday January 21 2020, @08:29PM

  by nishi.b (4243) on Tuesday January 21 2020, @08:29PM (#946527)

  Thanks for the precision, I really thought temporal coherence was necessary for a laser.

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