Sideband-free tunable and switchable dual-wavelength mode-locked fiber laser based on the Lyot filter and spontaneous radiation peaks

Abstract

We demonstrate a compact tunable and switchable dual-wavelength fiber laser based on the Lyot filtering effect and the spontaneous radiation peaks of gain fiber. By introducing a period of polarization-maintain Er-doped fiber (PM-EDF), stable dual-wavelength pulses can operate in both the anomalous dispersion region and the normal dispersion region. The corresponding repetition frequency difference of the dual wavelengths has excellent stability while the relative center wavelength can be adjusted in the range of 5 nm to 13 nm. There is no existence of significant sidebands in the optical spectrum during the whole tuning process. This dual-wavelength laser based on two spontaneous radiation peaks in the shorter wavelength direction has great application potential. Our work provides a new design solution for dual-comb sources (DCSs).

Bimetallic solid solution MAX phase Ti2NbAlC2 as saturable absorber for passively Q-switched Er3+-doped fiber laser

“…A Q-switched operation with a central wavelength of 1531.43 nm and a 3 dB bandwidth of 1.41 nm was obtained at a pump power of 250 mW. We considered that the generation of the dual-peak phenomenon may be caused by the spontaneous radiation peak of EDF, the modulation of saturable absorber and the loss of the fiber laser cavity [45]. Figure 6(b) shows the output pulse trains at 180 mW, 210 mW, 240 mW, 270 mW, and 300 mW.…”

Tunable wide spacing all-fiber dual-wavelength holmium-doped fiber laser using a Lyot filter operating above 2 µm

“…The second PC was used in this setup to help optimize the polarization of the propagating signal. This is due to the effect of the various components within the cavity, particularly the polarizer (POL), which requires an optimal polarization of the propagating signal to reduce the loss within the cavity [26][27][28]. While a single PC can be used to optimize the signal's polarization, the use of the second PC can help to refine the adjustments [29][30][31].…”

Bright/dark switchable mode-locked fiber laser based on alcohol

“…The spectral width is slightly narrow owing to the combination of spectral filtering effect, the nonlinear effect of TDF, and loss in the cavity. Notably, the Kelly sidebands of the optical spectrum disappear, which may be attributed to the NPE [29] . It can be interpreted that different polarization states means various intensity gain and/or loss; based on the complexity of the gain modulation and NPE effect, the sidebands vanish.…”