1. Subharmonic Entrainment Breather Solitons in Ultrafast Lasers
- Author
-
Tianhao Xian, Wenyan Zhang, Wenchao Wang, and Li Zhan
- Subjects
Physics ,Subharmonic ,Exceptional point ,Breather ,Physics::Optics ,General Physics and Astronomy ,Laser ,01 natural sciences ,Cavity loss ,law.invention ,Nonlinear Sciences::Exactly Solvable and Integrable Systems ,law ,Quantum electrodynamics ,0103 physical sciences ,Soliton ,010306 general physics ,Entrainment (chronobiology) ,Nonlinear Sciences::Pattern Formation and Solitons ,Ultrashort pulse - Abstract
We study theoretically and experimentally the subharmonic entrainment (SHE) breather soliton in mode-locked lasers for the first time, in which the ratio of the breather period to the round-trip time is an integer. We build a non-Hermitian degeneracy map of breather soliton, and illustrate that SHE arises between the two exceptional points (EPs). We obtain SHE at the ratio of 20, observe the evolution of breather soliton when tuning the gain and/or cavity loss, and prove that this phenomenon can improve the stability of breather soliton. Our research brings insight into the EP physics of ultrafast lasers and makes the mode-locked laser a powerful test bed for non-Hermitian degeneracy, which may open a new course in ultrafast laser research.
- Published
- 2020