def electric_field_amplitude_intensity(s0,Omega=1.0e6):
	'''This function returns the value of E0 (the amplitude of the electric field)
	at a given saturation parameter s0=I/I0, where I0=2.50399 mW/cm^2 is the
	saturation intensity of the D2 line of Rubidium for linearly polarized light.'''
	e0=hbar*Omega/(e*a0) #This is the electric field scale.
	
	I0=2.50399 #mW/cm^2
	I0=1.66889451102868 #mW/cm^2
	
	I0=I0/1000*(100**2) #W/m^2
	r_ciclic=4.226983616875483 #a0
	gamma_D2=2*Pi*6.065e6/Omega # The decay frequency of the D2 line.
	E0_sat=gamma_D2/r_ciclic/sqrt(2.0)

	E0_sat=E0_sat*e0
	I0=E0_sat**2/2/c/mu0

    #return sqrt(c*mu0*s0*I0/2)/e0
	#return sqrt(c*mu0*s0*I0)/e0
	return sqrt(2*c*mu0*s0*I0)/e0