A switchable multiwavelength fibre laser with polarization-maintaining erbium fibre

Abstract

A multiwavelength fibre laser with wavelength-switchable operation has been demonstrated, utilizing the combined effects of polarization hole burning and intensity-dependent transmission. Polarization-maintaining erbium fibre (PM-EDF) with an anisotropic gain is used as the gain medium to suppress the mode competition. Simultaneously, the PM-EDF and the polarizer in the cavity form an equivalent periodic filter. Four lasing wavelengths simultaneously oscillating are obtained, which are stable over an hour at room temperatures. Furthermore, by adjusting the polarization controllers the laser can also produce triple-, dualand single-wavelength lasing oscillations, which can be switched among the four simultaneously oscillating wavelengths.

The generation of a lower threshold multiwavelength fiber laser in the L-band region assisted by a Sagnac loop mirror

“…Thus, several MWEDFL generation methods have been investigated in order to solve this problem, including liquid nitrogen cooling, multiple gratings, tunable filter combs, SBS, nonlinear polarization rotation, four wave mixing, hybrid gain media and spatial mode filtering [1,[6][7][8]. In addition, other approaches are: a switchable EDF ring laser based on a fiber Bragg grating (FBG) based Fabry-Perot filter, a polarization maintaining fiber Sagnac loop [2] and a polarization maintaining EDF with a polarizer to enhance the inhomogeneities of the polarization and intensity in the cavity [9].…”

A stable and uniform-amplitude multi-wavelength erbium-doped fiber laser based on nonlinear polarization rotation and a polarization-maintaining fiber loop mirror

“…To overcome this obstacle, different methods have been investigated to alleviate mode competition and realize multi-wavelength oscillations at room temperature in EDFLs, in addition to the straightforward method of cooling EDF in liquid nitrogen [1], which is impractical in many applications. These include the introduction of the polarization hole burning effect [2,3], frequency shifters [4], nonlinear effects such as four-wave mixing [5][6][7], independent gain media [8,9], stimulated Brillouin scattering or stimulated Raman scattering in the laser cavity [10][11][12][13][14][15], nonlinear optical loop mirrors (NOLM) [16][17][18][19] and nonlinear amplifying loop mirrors (NALM) [20,21]. Nonlinear polarization rotation (NPR) [22][23][24], which is used to suppress super-mode noise and to equalize the amplitude, can induce wavelength-dependent and intensitydependent loss (IDL) in generating multi-wavelength oscillations in EDFLs.…”

Multi-wavelength fiber lasers operated in stretched-pulse mode-locked regimes with a very compact configuration

“…For some time, the nonlinear polarization rotation (NPR) technique has been extensively demonstrated to implement stable room temperature multi-wavelength fiber lasers owing to the intensity and wavelength dependent loss induced by the NPR effect to suppress the mode competition and generate the multi-wavelength oscillation as well as the simplicity and low-cost characteristics of NPR configuration [7,[12][13][14]. These schemes based on NPR have been obtained by using a long single mode fiber (SMF [12]), a polarization maintaining fiber (PMF [14,15]) or highly nonlinear fiber [7]. However, the preceding schemes have to employ a SMF as long as several kilometers or special fibers to produce multi-wavelength lasing, which are against the compactness, economy and stability of the fiber lasers.…”