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Register a new userPhase coherence and extreme self phase modulation
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P. Kinsler
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I study how pulse to pulse phase coherence in a pulse train can survive super-broadening by extreme self phase modulation (SPM). Such pulse trains have been used in phase self-stabilizing schemes as an alternative to using a feedback process. However, such super-broadened pulses have undergone considerable distortion, and it is far from obvious that they necessarily retain any useful phase information. I propose measures of phase coherence (i.e. supercontinuum coherence) applicable to such pulse trains, and use them to analyze numerical simulations comparable to self-stabilization experiments.
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We present a simple approach to predict the main features of optical spectra affected by self-phase modulation (SPM), which is based on regarding the spectrum modification as an interference effect. A two-wave interference model is found sufficient to describe the SPM-broadened spectra of initially transform-limited or up-chirped pulses, whereas a third wave should be included in the model for initially down-chirped pulses. Simple analytical formulae are derived, which accurately predict the positions of the outermost peaks of the spectra.
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