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Use graphene to multiply a frequency

Use graphene to multiply a frequency

In addition to the multiple applications that we have already seen of the so-called "wonder material" to date, according to new calculations by a German physicist at the University of Augsburg, it could be use graphene as a frequency multiplier to achieve radiation in the terahertz frequency range.

According to a published article nanotechweb.org, new calculations by a German physicist indicate that graphene could function as an intrinsically strong non-linear device or "frequency multiplier." This means that the nanomaterial, also known as "wonder material", could be used to produce radiation in the terahertz frequency range. irradiating it with more easily accessible frequencies, such as microwaves.

Graphene is a nanomaterial consisting of a two-dimensional sheet of carbon just one atom thick, created in 2004 by Andre Geim and his colleagues at the University of Manchester and the Institute of Microelectronics Technology in Chernogolovka, Russia.

Graphene is made of graphite, the form of carbon used in pencils, and has some unusual physical properties, including the fact that the electrons in the material behave like relativistic particles that have no mass at rest and travel at about 106m / s. Although this is about 300 times slower than the speed of light in vacuum, it is still much faster than the speed of electrons in a normal conductor.

Sergey Mikhailov's new study

Now, Sergey Mikhailov, from the University of Augsburg, has predicted that When graphene is irradiated with electromagnetic waves, it emits radiation with a higher frequency harmonic resonance, therefore, it can be used as a frequency multiplier. In other words, if the sample is irradiated with a certain frequency of light, it will reflect light of a higher frequency.

This "frequency transformation" could be used to produce radiation at frequencies for which there are no appropriate sources. For example, it is difficult to produce frequencies above 100GHz and down to 1–10THz (1012Hz, also known as the terahertz gap). In contrast, there are numerous sources of microwave radiation for frequencies below 100GHz. Scientists could therefore "multiply" microwave frequencies using a non-linear device, such as graphene, to produce radiation in the terahertz range, Mikhailov notes in his work published in the magazine Europhysics Letters.

These terahertz radiation sources could be applied in many fields, such as security and defense, medicine, astronomy, and biological research.

Terahertz radiation penetrates many materials (except metals) and therefore can be used to "see" through packages and packages at airports, for example.

"In medicine it could be used to obtain images of cancerous tumors and make an early diagnosis of the disease, ”says Mikhailov.

Astronomers are also interested in terahertz radiation because the cosmic microwave background, originated in the Big Bang, includes a terahertz component.

Source: Nanotechweb

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Video: 2014 Terahertz Electronics for Sensing Applications (September 2020).