Analysis of magneto-optic Kerr effect signals from convergent Gaussian beams

The method uses an amplitude summation of plane-wave elements of the incident beam over all possible angles of incidence and over all azimuths. The Gaussian nature of the beam is dealt with by incorporating an amplitude modulation function into the integration process. Numerical results of the calculation demonstrate clearly that the shot-noise limited signal/noise ratio has a rather weak dependence upon the numerical aperture of the beam, a result consistent with reported experimental observation (see G.A. Connell et al. 1983)