What is the intensity of an electromagnetic radiation?

[ecastro]

How can I compute the intensity of an electromagnetic radiation if I know $e_x, e_y, e_z, h_x, h_y,$ and $h_z$, where $e_i$ is the electric field component at $i$ and $h_i$ is the magnetic field component, also at $i$?

Thank you in advance.

 

[jtbell]

See the discussion of Poynting flux at about the middle of this page:

http://farside.ph.utexas.edu/teaching/em/lectures/node89.html

I assume that by "intensity" you mean energy transported by the radiation per unit area per unit time, e.g. J/(m²·s) = W/m².

 

[ecastro]

See the discussion of Poynting flux at about the middle of this page:

http://farside.ph.utexas.edu/teaching/em/lectures/node89.html

I assume that by "intensity" you mean energy transported by the radiation per unit area per unit time, e.g. J/(m²·s) = W/m².

The intensity here is the amount of radiation received by a detector. Is it the same as the radiation per unit area per unit time?

 

[jtbell]

If you want the amount of energy received by a detector that has a certain area, during a certain amount of time, then you multiply the Poynting flux (as given on that page) by the area and the time.