Tunable and switchable dual-wavelength mode-locked Tm^3+-doped fiber laser based on a fiber taper

Abstract

We demonstrate a self-starting dual-wavelength mode-locked fiber laser at a 2 μm spectral region by using a fiber taper in a Tm³⁺-doped ring fiber cavity. The fiber taper fabricated with a flame brushing technique was used as a periodic filter with a modulation depth of ~3.61 dB and a modulation period of ~7.3 nm, respectively. Diverse dual-wavelength regimes including continuous wave (CW)/multi-soliton, soliton/multi-soliton, and soliton/soliton regimes were obtained by adjusting pump power. Wavelength tuning for the dual-wavelength was also precisely controllable through stretching the fiber taper carefully. The tuning range was ~7 nm which was limited by the modulation period of the taper. By inserting a 10.0 m dispersion compensation fiber (DCF) into the fiber cavity, a stable dual-wavelength dissipative-soliton operation was obtained at 2 μm spectral region for the first time.

Coexistence of dissipative soliton and stretched pulse in dual-wavelength mode-locked Tm-doped fiber laser with strong third-order dispersion

“…In addition, with the large comb filter period, modecompetition of the dual-wavelength mode-locking is in fact suppressed by the combined functions of NPE induced wavelength-dependent loss and unflattened gain of Tm-doped fiber, and as a result the center wavelength separation of the dual-wavelength mode-locking is not only decided by the comb filter period of 51.6 nm. Note that the unflatteness of the gain profile can also be validated by our previous work with a fiber taper filter based dualwavelength mode-locking [32], where the gain unflatteness is a reasonable explain for mode competition suppression because no any additional measure is used. Here, by carefully adjusting the PCs, the coexistence patterns with a large center wavelength separation of 73.8 nm is obtained, which is greatly different from the simulation where unflattened property of gain fiber is ignored.…”

1700 nm and 1800 nm band tunable thulium doped mode-locked fiber lasers

“…The emission wavelength can be manipulated by tuning the polarization controller. The laser emits at a fixed peak position at any fixed state of the cavity polarization because the nonlinear polarization evolution prohibits the periodic spectral filters, which affect the entire range of the emission spectrum 34 , 35 .

Figure 4 Tunable lasing emission of a non-ASE suppressed Tm-doped mode-locked all-fiber laser in the range of 1850–1920 nm enabled by the non-linear polarization rotation.

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L-band Wavelength-Switchable Dissipative Soliton Resonance Er-doped Fiber Laser

“…Thus, making pulse operating in DSR region is an appropriate way to generate high power nanosecond square-profile pulse in mode-locked cavity. On the other hand, tunable or switchable wavelength mode-locked fiber lasers have attracted much attention in recent years, which can be widely applied to wavelength division multiplexing communication, optical signal processing and precision spectroscopy [19], and there are various methods to realize them, such as nonlinear polarization evolution (NPE) [20], [21], fiber taper [22], Bragg grating [23], [24], hybrid mode-locked technique [25] and so on. However, there is little relevant reported work at pulses in DSR region.…”