Inducing current with magnetic field from light

In summary, the conversation discussed the possibility of using the magnetic fields of light to induce an electrical current, particularly in accelerating structures. It was mentioned that this has been achieved using high powered ultrafast lasers, with the term "ponderomotive force" being used in plasma physics. This technique has been used to create table-top particle accelerators since 2004. It was also noted that this is similar to what happens in a radio, but with lower frequencies of light.
  • #1
saime
3
0
Hey everybody,

I was wondering if one could use the magnetic fields of light to induce an electrical current, even if it was just a small one. I'm not talking about the use of photovoltaic cells, but the actual magnetic fields of light.

Thanks
 
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  • #2
In accelerating structures, the EM wave in the cavity induces wall currents due to the changing E and B field, depending on the modes/geometry of the field. So having induced current due to EM radiation is rather common.

Zz.
 
  • #3
Yes, it has been done with light, using high powered ultrafast lasers. The term used in plasma physics is "ponderomotive force"; see http://farside.ph.utexas.edu/teaching/plasma/lectures/node26.html

Note that the final expressions are in terms of the electric field, but the derivation uses Faraday's law to "convert" the rid the expression of the B field.

The ponderomotive force is used with high-powered ultrafast lasers to create table-top particle accelerators:
http://www.colorado.edu/physics/phys7810_005/phys7810_005_fa09/articles/Malka_NaturePhys_2008.pdf

This was first done about 2004; some of the work was done across the hall from my lab:
http://accelconf.web.cern.ch/accelconf/IPAC10/papers/thpec011.pdf
 
  • #4
Note that this is exactly what happens in a radio - just with lower frequencies of light.
 
  • #5
Thanks for the answers everyone.
 

1. How does inducing current with magnetic field from light work?

Inducing current with magnetic field from light is based on the principle of electromagnetism. When light, which consists of electromagnetic waves, passes through a conductor, it creates a changing magnetic field. This changing magnetic field then induces a current in the conductor, which can be harnessed for various applications.

2. What are the practical applications of inducing current with magnetic field from light?

Inducing current with magnetic field from light has a wide range of practical applications, including solar energy generation, wireless power transfer, and optical communication. It is also used in devices such as photodetectors and solar cells.

3. How is the strength of the induced current affected by the intensity of light?

The strength of the induced current is directly proportional to the intensity of light. This means that as the intensity of light increases, the induced current also increases. However, there is a limit to how much current can be induced, as too much intensity can damage the conductor.

4. Can any material be used to induce current with magnetic field from light?

In theory, any material can be used to induce current with magnetic field from light. However, materials that are good conductors, such as metals, are more efficient at converting light into current. On the other hand, materials that are poor conductors, such as glass, do not induce much current.

5. How does the angle of incidence of light affect the induced current?

The angle of incidence, which is the angle at which light hits the conductor, affects the induced current. When the angle of incidence is perpendicular to the conductor, the induced current is maximized. As the angle deviates from perpendicular, the induced current decreases, and when the angle is parallel to the conductor, there is no induced current.

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