Multiscale ordinal symbolic analysis of the Lang-Kobayashi model for external-cavity semiconductor lasers: a test of theory

NIANQIANG LI; LUCIANO ZUNINO; ALEXANDRE LOCQUET; BYUNGCHIL KIM; DAEYOUNG CHOI; WEI PAN; DAVID S. CITRIN

IEEE JOURNAL OF QUANTUM ELECTRONICS

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Lugar: New York; Año: 2015 vol. 51 p. 2200206 - 2200206

0018-9197

We study experimentally and theoretically the permutation entropy (PE) of the optical intensity I(t) of an external-cavity semiconductor distributed feedback laser in the coherence collapse regime. Our PE analysis allows us to uncover the intrinsic dynamical complexity at multiple timescales of the delayed-feedback system, as well as to investigate how the experimental observations can be determined by modeling. An overall good agreement between experiment and theory corroborates the effectiveness of the Lang-Kobayashi model, though the model underestimates the entropy on the timescale of the relaxation oscillations and can lead to a time-delay signature that is less evident than in experiment, indicating a potential vulnerability of chaos encryption. This provides a critical test of the standard theoretical framework in which chaotic external-cavity semiconductor lasers are understood.