Theory of the optical absorption of light carrying orbital angular momentum by semiconductorsG. F. Quinteiro and P. I. Tamborenea
Departamento de Física “J. J. Giambiagi”, Universidad de Buenos Aires - Ciudad Universitaria, Pabellón I, C1428EGA, Ciudad de Buenos Aires, Argentina
received 20 November 2008; accepted in final form 25 January 2009; published February 2009
published online 16 February 2009
We develop a free-carrier theory of the optical absorption of light carrying orbital angular momentum (twisted light) by bulk semiconductors. We obtain the optical transition matrix elements for Bessel-mode twisted light and use them to calculate the wave function of photo-excited electrons to first-order in the vector potential of the laser. The associated net electric currents of first and second-order on the field are obtained. It is shown that the magnetic field produced at the center of the beam for the = 1 mode is of the order of a millitesla, and could therefore be detected experimentally using, for example, the technique of time-resolved Faraday rotation.
78.20.Bh - Theory, models, and numerical simulation.
78.20.Ls - Magnetooptical effects.
78.40.Fy - Semiconductors.
© EPLA 2009