Transmission of phase modulated laser light through a thin semiconductor film in the excitonic spectral range and an optical analog of the Feshbach effect

A theoretical and numerical analysis of the transmission of phase modulated laser pulses through a thin film with excitonic nonlinearity is performed. It is shown that, by choosing the modulation law, one can efficiently control the optical nonlinearity of the film down to the inversion of the sign of nonlinearity.