A laser beam has intensity 2.5 × 1014 W m–2. Find the amplitudes of electric and magnetic fields in the beam.

Given: The intensity of laser beam =2.5 × 1014W m-2.


We have to find the amplitudes of electric and magnetic field. The


amplitude of the electric field is related to the intensity of the wave


by the relation



where


ϵ0 is the electric permittivity of free space(vacuum) and is equal to 8.85 × 10-12 C2 N-1 m-2, C is the speed of light in vacuum and is equal to 3 × 108 m s-1 and E0 is the amplitude of electric field.





.


The amplitudes of electric and magnetic fields are related as



where B0 is the amplitude of magnetic field in free space.


Thus the value of magnetic field will be


.


The electric field amplitude is and the magnetic field amplitude is .


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