We consider coupled non-linear Schrodinger equations (CNLSE) which govern the propagation of non-linear waves in bimodal optical fibers. The non-linear transform of a dual-frequency signal is used to generate an ultra-short-pulse train. To predict the energy and width of pulses in the train, we derive three new types of travelling periodic-wave solutions, using the Hirota bilinear method. We also show that all the previously reported periodic wave solutions of CNLSE can be derived in a systematic way, using the Hirota method. (C) 2003 Published by Elsevier Science B.V.
- optical fiber
- coupled non-linear Schrodinger equations
- periodic solutions
- Hirota method
- INDUCED MODULATIONAL INSTABILITY
- PULSE-TRAIN GENERATION
- FREQUENCY BEAT SIGNAL