Pulse evolution and multi-pulse state of coherently coupled polarization domain walls in a fiber ring laser

Abstract

Pulse evolution and multi-pulse state of coherently coupled polarization domain walls (PDW) is experimentally demonstrated in a novel fiber ring laser. Versatile pulse shapes benefit by wide range moving of PDW in the weakly birefringent fiber. The 8.6 m short-cavity structure is more compact and accessible based on a 976 nm pump with nearly zero negative dispersion (-0.0002 ps2). Besides, multi-pulse patterns such as PDW splitting, harmonic mode-locking, and periodic soliton collision are also observed under larger net negative dispersion (-3.09 ps2) and 151m-longer cavity. This is the first demonstration of coherently coupled PDW in a fiber laser using a bandpass filter and the formation of coherently coupled PDW is ascribed to the BPF’s force filtering.

Advances and Challenges of Ultrafast Fiber Lasers in 2–4 µm Mid‐Infrared Spectral Regions

“…More recently, Zhu et al demonstrate spectrally flat high-power mid-IR SC generation with record-breaking power of 33.1 W and spectral ranges of 1.9-4.02 μm by a Tm 3+ -doped fiber amplifiers with repetition rate of 4.08 MHz, demonstrating the advantages of 2 μm noiselike pulse pump in high-power mid-IR SC generation. [296]…”

Polarization domains and self-mode-locked pulses in an erbium-doped fiber laser

“…The typical feature of such pulses is that the polarization of light is periodically switched between two orthogonal directions at round-trip frequency. And for practical applications, PDs were studied to achieve the square-shaped pulse [15][16][17][18][19] and have been used in optical fibers as topological bits for data transmission [23] . Due to the existence of birefringence in fiber, the fundamental mode contains two orthogonal polarization modes with different propagation constants.…”

“…Due to the existence of birefringence in fiber, the fundamental mode contains two orthogonal polarization modes with different propagation constants. PDW pulses are obtained due to the cross coupling of the two orthogonal polarization modes [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] . In 2009, Zhang et al [6] first experimentally observed PDW solitons in weakly birefringent cavity fiber lasers, which were formed due to the strong coherent cross-polarization coupling of light in the fiber lasers.…”

“…The pulse durations of the PDs can be changed with the variation of the cavity parameters, and the PDWs are usually formed as bright pulses, dark pulses, or bright-dark pulse pairs with different temporal profiles [12][13][14][15][16][17][18][19] . Under a certain cavity condition, the PDs will split to form irregularly distributed multidomains [15][16][17] , harmonic PDWs [18] , or evolve into other types of pulses [20,22] . The research shows that the strength of the coherent or incoherent cross coupling can induce various domain states.…”

Operating Vector Solitons with Chirped Sech Pulse Shapes

“…Optical soliton in optical fiber has already been studied by many researchers during past decades [1][2][3][4][5][6][7][8][9]. Commonly, optical soliton can be formed in an anomalous dispersion regime under the balance between group-velocity dispersion and self-phase modulation.…”