“…The first experimental observation of XPM spectral effects dates to early 1986, when it was reported that intense picosecond pulses could be used to enhance the spectral broadening of weaker pulses copropagating in bulk glasses (Alfano et al, 1986). Since then, several groups have been studying XPM effects generated by ultrashort pump pulses on copropagating Raman pulses (Schadt et al, 1986;Schadt and Jaskorzynska, 1987a;Islam et al, 1987a;Alfano et al, 1987b;Baldeck et al, 1987b-d;Manassah, 1987a, b;Hook et al, 1988), second harmonic pulses (Alfano et al, 1987a;Manassah, 1987c;Manassah and Cockings, 1987;Ho et al, 1988), stimulated four-photon mixing pulses , and probe pulses (Manassah et al, 1985;Agrawal et al, 1989a;Baldeck et al, 1988a, c). Recently, it has been shown that XPM leads to the generation of modulation instability (Agrawal, 1987;Agrawal et al, 1989b;Schadt and Jaskorzynska, 1987b;Baldeck et al, 1988bBaldeck et al, , 1988dGouveia-Neto et al, 1988a, b), solitary waves (Islam et al, 1987b;Trillo et al, 1988), and pulse compression (Jaskorzynska and Schadt, 1988;Manassah, 1988;Agrawal et al, 1988).…”