Flexible rectangular wave-breaking-free pulse generation in actively mode-locked ytterbium-doped fiber laser

Abstract

We demonstrate nanosecond scale rectangular wave-breaking-free pulse generation in an actively mode locked Yb-doped fiber laser based on a combined action of active periodic cavity loss modulation and nonlinear polarization rotation effect. The pulse width of the laser can be controlled in the range of 890 ps to above 124 ns instantaneously by adjusting the electrical signal applied on the modulator. As high as 19.8 nJ wave-breaking-free pulse is achieved with maximum available pump power. The output pulse temporal dynamics exhibit various distinct characteristics under different modulation and polarization control. The laser presents unusually flexible tunabilities in pulse width, pulse energy and pulse shape.

Dual-wavelength rectangular pulse erbium-doped fiber laser based on topological insulator saturable absorber

“…Distinct from previous work [3][4][5][6][7][8][9][10], that is, the modelocked pulse operating in DSR regime is wave-breaking-free. Surprisingly, we observed the HML of the dual-wavelength rectangular pulse in experiments.…”

“…Since then, several actively/passively mode-locked techniques have been exploited for achieving rectangular pulse in fiber lasers. Compared with active scheme [3], passive schemes share more benefits: (1) very simple, compact, and low-cost without a modulator required; and (2) easily achieving rectangular pulses with ultrahigh peak power. To date, several passive mode-locking techniques, such as nonlinear polarization rotation (NPR) [4][5][6][7][8][9], nonlinear amplifying loop mirror [10], saturable absorber {SA, e.g., graphene oxide (GO) [11]}, and even hybrid NPR and active mode-locking [12] have been used to generate the rectangular pulse in the fiber lasers.…”

Mega-Hertz repetition rate broadband nano-second pulses from an actively mode-locked Yb-fiber laser

“…Only one group has reported an active mode-locked dissipative soliton resonance fiber laser at 1 µm, where pulse width from sub-ps to 124 ns could be obtained. The peak power clamping effect was provided by a nonlinear polarization rotation mechanism due to a polarization sensitive modulator and a polarization controller [9].…”

Tunable SESAM-Based Mode-Locked Soliton Fiber Laser in Linear Cavity by Axial-Strain Applied to an FBG

“…This type of fiber lasers have been experimentally demonstrated as an alternative to solid-state lasers because of their low cost, compact cavity structure, heat dissipation properties, free-alignment and overall high stability [5][6][7][8][9]. Furthermore, active mode-locked fiber lasers also require additional switching electronics and complex driven modulators [10][11][12]. Particularly, the capability of passively mode-locked fiber lasers to generate ultrafast solitons are of important interest in practical applications such as optical fiber sensing, biomedical diagnostics, material processing, nonlinear optics, terahertz generation and ultrahigh speed communications [13][14][15].…”