A light wave is traveling in glass of index 150 The electric

A light wave is traveling in glass of index 1.50. The electric field component of the wave, in glass is known to be 100V/m. Find the amplitude of the magnetic field. Find the time averaged magnitude of the irradiance. How does the irradiance of this light wave in glass compare to the irradiance in air?

Solution

a)

Amplitude of magnetic field

B=E*(n/c) =100 *(1.5/3*10⁸)

B=5*10^-7T

b)

Time averaged magnitude of the irradiance is given by

E_e =(1/2)*(c/nu_o)*B² =(1/2)*(3*10⁸/1.5*4pi*10^-7)*(5*10^-7)²

E_e=19.89 W/m²

^c)

For air n=1

E_e,glass/E_e,air =(1/2)*(c/n_glassu_o)*B²/(1/2)*(c/n_airu_o)*B² =n_air/n_glass

E_e,glass/E_e,air =1/1.5 =0.6667