Abstract
High-order mode fiber lasers are gathering the rising attentions from fundamental researches to practical applications due to their distinctive spatial and temporal properties. Here, we demonstrate a carbon nanotube mode-locked two-mode fiber laser and investigate the formation and evolution process of the soliton based on the time-stretch dispersive Fourier transform method. Stable single pulse and bound-state pulses are observed at pump powers of 32.0 and 41.3 mW, respectively. Attributing to the coexistence of fundamental mode and first group high-order modes, the optical spectrum exhibits slight intensity modulations and the autocorrelation trace shows additional small side lobes. Similar to that of single-mode fiber lasers, the buildup process of soliton includes the relaxation oscillation, beating behavior, and stable mode-locking state. However, owing to the interplay between two transverse modes in the two-mode fiber laser, the duration and fluctuation intensity of the relaxation oscillation are much larger than that of single-mode fiber lasers.
Highlights
Single-mode fiber (SMF) lasers have brought a huge impact on fundamental researches and practical applications due to their inherent advantages of cost-effectiveness, compact structure, excellent beam quality, and high reliability [1]–[3]
Mode-locked SMF lasers are capable of generating picosecond or femtosecond pulses, providing an excellent platform to study the dynamic evolution of nonlinear optical waves [9], [10]
A CW is first obtained in the proposed two-mode fiber (TMF) laser when the laser pump reaches 17.8 mW
Summary
Single-mode fiber (SMF) lasers have brought a huge impact on fundamental researches and practical applications due to their inherent advantages of cost-effectiveness, compact structure, excellent beam quality, and high reliability [1]–[3]. These fiber lasers can be categorized as continuous-wave (CW) [4], Q-switched [5], [6], and mode-locked fiber lasers [7], [8] in the temporal domain. SMFs exhibit a slight modal birefringence with a beat length of ∼10 m because of unintentional variations of the core shape and anisotropic stress on the fiber. By controlling the dispersion and birefringence of fiber, polarization-locked vector solitons [12] and group velocity-locked vector
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
