Self- and cross-phase modulation of ultrashort light pulses in an   inertial Kerr medium: spectral control of squeezed light
  Quantum theory of self-phase and cross-phase modulation of ultrashort light pulses in the Kerr medium is developed with taking into account the response time of an electronic nonlinearity. The correspondent algebra of time-dependent Bose-operators is elaborated. It is established that the spectral region of the pulse, where the quadrature fluctuations level is lower than the shot-noise one, depends on the value of the nonlinear phase shift, the intensity of another pulse, and the relaxation time of the nonlinearity. It is shown that the frequency of the pulse spectrum at which the suppression of fluctuations is maximum can be controlled by adjusting the other pulse intensity. 
F. Popescu, A. S. Chirkin