Abstract

Results of a stability analysis for periodic and almost periodic structures are presented, showing the required incoming intensity for side band instability to occur. This work is motivated by the fact the instability results in gap solitons; lowering the instability threshold, therefore, leads to a lowering of the threshold for the formation of gap solitons as well. The work shows that the threshold for a structure with a suitably chosen chirp can be lower than that for a periodic medium.

© 1992 Optical Society of America