Optics and Photonics Society of Iran

Self Phase Modulation (SPM) is one of the nonlinear effects in which the laser pulse modulates the refractive index of the nonlinear medium and the modified refractive index affects the phase of the laser pulse in consequence, and results in the frequency modulation of the laser pulse. This phenomenon is important not only in nonlinear crystals but also in transport of the laser pulses in plasma mediums in which there is a capability of generation of a continues frequency spectrum. Therefore, in this research, the SPM effect was simulated by use of a new approach based on the wave-kinetic theory (capable of introducing the pulse spectrum) and without the consideration of the phase concept, the spectral broadening of the laser pulse was observed as a result of its interaction with plasma.