Modulational instability of spatially broadband nonlinear optical pulses in four-state atomic systems.
The modulational instability of broadband optical pulses in a four-state atomic system is investigated. In particular, starting from a recently derived generalized nonlinear Schrödinger equation, a wave-kinetic equation is derived. A comparison between coherent and random-phase wave states is made. It is found that the spatial spectral broadening can contribute to the nonlinear stability of ultrashort optical pulses. In practical terms, this could be achieved by using random-phase plate techniques.
Marklund
M
M
Centre for Nonlinear Physics, Department of Physics, Umeå University, SE-901 87 Umeå, Sweden.
Shukla
P K
PK
Bingham
B
B
Mendonça
J T
JT