General method of passive optical pulse peak intensity stabilization through controlled self-phase modulation and over-compression

A method of peak intensity stabilization of optical pulses is presented which is based on the combination of self-phase modulation (SPM) and an optical compressor. Spectral broadening via SPM can occur for intense laser pulses propagating through a nonlinear medium. For Gaussian pulses, this nonlinear broadening results in a nonlinear spectral phase, which positively chirps the pulse. Because this is a nonlinear process, the amount of spectral broadening depends on the intensity of the laser pulse with increased broadening for higher intensities. Here we propose a technique of peak intensity stabilization by accumulating a modest amount of nonlinear spectral phase on a pulse via SPM and subsequently introducing a negative net group delay dispersion (GDD) with an optical compressor. For the appropriate value of compressor GDD, the energy-dependent chirp is balanced such that the peak intensity of the pulse is stabilized. Simulations of this method for realistic pulse parameters predict an increase in peak intensity stability by well over an order of magnitude.