Recently, the dissipative soliton (DS) generation in the positive fourth-order-dispersion (FOD) fiber laser has been theoretically predicted, namely dissipative pure-quartic soliton (DPQS), featuring a higher energy-scaling ability compared to conventional DS dominated by positive group velocity dispersion. Here, we discover that the formation of spectral sidebands is always accompanying by the stabilized DPQS in the fiber laser, which is different from the conventional DS. Due to the combination of positive FOD and self-phase modulation, low- and high-frequency components are distributed at the leading and trailing edges of the pulse, forming the pedestals that propagate with it.
View Article and Find Full Text PDFPhase noise characteristics of ultrafast fiber lasers are critical to practical applications, such as high-resolution photonics sampling. Herein, we investigated the impact of pump power and linear phase shift difference of counter-propagating light in the nonlinear amplifying loop mirror on phase noise suppression in a figure-9 fiber laser. Based on these results, we proposed a method for intelligent suppression of phase noise through real-time feedback control.
View Article and Find Full Text PDFControlling the coherence of chaotic soliton bunch holds the promise to explore novel light-matter interactions and manipulate dynamic events such as rogue waves. However, the coherence control of chaotic soliton bunch remains challenging, as there is a lack of dynamic equilibrium mechanism for stochastic soliton interactions. Here, we develop a strategy to effectively control the coherence of chaotic soliton bunch in a laser.
View Article and Find Full Text PDFWe develop an all polarization-maintaining (PM) 920 nm Nd-doped fiber amplifier delivering a train of pulses with ∼0.53 W average power and sub-50 fs duration. The sub-50 fs pulse benefits from the pre-chirping management method that allows for over 60 nm broadening spectrum without pulse breaking in the amplification stage.
View Article and Find Full Text PDFFocusing light inside scattering media is a long-sought goal in optics. Time-reversed ultrasonically encoded (TRUE) focusing, which combines the advantages of biological transparency of the ultrasound and the high efficiency of digital optical phase conjugation (DOPC) based wavefront shaping, has been proposed to tackle this problem. By invoking repeated acousto-optic interactions, iterative TRUE (iTRUE) focusing can further break the resolution barrier imposed by the acoustic diffraction limit, showing great potential for deep-tissue biomedical applications.
View Article and Find Full Text PDFThe self-starting performance of a figure-9 fiber laser is critically dependent on the phase shift difference between the counter-propagating beams. Herein, we propose an effective approach to dynamically control the phase shift difference in a figure-9 fiber laser by utilizing the thermal nonlinearity of graphene-decorated microfiber device. With the adjustment of the control laser power injected into the graphene-decorated microfiber, the self-starting mode-locked threshold of the figure-9 fiber laser can be attained in a flexible pump power range, i.
View Article and Find Full Text PDFThe evolution of multiphoton microscopy is critically dependent on the development of ultrafast laser technologies. The ultrashort pulse laser source at 1.7 µm waveband is attractive for in-depth three-photon imaging owing to the reduced scattering and absorption effects in biological tissues.
View Article and Find Full Text PDFSoliton pulsation is one of the most fascinating phenomena in ultrafast fiber lasers, owing to its rich nonlinear dynamics and potential generation of high peak power pulse. However, it is still a challenge to efficiently search for pulsating soliton in fiber lasers because it requires a fine setting of laser cavity parameters. Here, we report the autosetting soliton pulsation in a passively mode-locked fiber laser.
View Article and Find Full Text PDFThe bidirectional ultrafast fiber laser is a promising light source for dual-comb applications. The counter-propagating geometry could lead to soliton interaction through gain sharing, as well as the possible outcome of polarization instability. However, the polarization dynamics hidden behind the soliton interaction process in bidirectional fiber lasers were rarely investigated.
View Article and Find Full Text PDFPulsating soliton in ultrafast fiber lasers has interesting non-stationary dynamics, which is one of the hot topics in field of nonlinear soliton. So far, most researchers only focused on the spectral and temporal characteristics of pulsating soliton. However, the vector features of pulsating soliton were rarely studied.
View Article and Find Full Text PDFSoliton buildup dynamics in ultrafast fiber lasers are one of the most significant topics in both the fundamental and industrial fields. In this work, by using the dispersive Fourier transformation technique, the real-time spectral evolution of soliton buildup dynamics were investigated in the all-polarization-maintaining Yb-doped fiber laser, which is mode-locked by nonlinear polarization evolution technique through the cross splicing method. It was experimentally confirmed that the same stable soliton state could be achieved through different soliton starting processes because of the initial random noises.
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