Single- and dual-wavelength switchable erbium-doped fiber ring laser based on intracavity polarization selective tilted fiber gratings

Abstract

We have proposed and demonstrated a single-and dual-wavelength switchable Erbium doped fiber laser (EDFL) by utilizing intra-cavity polarization selective filters based on tilted fiber gratings (TFGs). In the cavity, one 45°-TFG is functioning as an in-fiber polarizer and the other 77°-TFG is used as a fiber polarization dependent loss (PDL) filter.The combined polarization effect from these two TFGs enables the laser to switch between the single-and dual-wavelength operation with single polarization state at room temperature. The laser output at each wavelength shows an optical signal to noise ratio (OSNR) of > 60dB and a side mode suppression ratio (SMSR) >50dB and a polarization extinction ratio of ~35dB. The proposed EDFL can give stable output under laboratory condition.2

Switchable dual-wavelength erbium-doped fibre laser utilizing two-channel fibre Bragg grating fabricated by femtosecond laser

“…For dual-wavelength lasing, the slope efficiency and threshold power for each wavelength are 0.149 % and 17.4 mw at ~1548.9 nm, and 0.140 % and 16.3 mw at ~1551.9 nm. Note that the slope efficiency here is higher than the one in previous report based on tilted FBGs where longer EDF is used [12]. Differences between the slope efficiency and threshold power for the two lasing wavelengths may result from the difference in the feedback given by TC-FBG, as the reflectivity is not exactly the same at the two selected wavelengths.…”

Erbium doped fiber lasers based on 45° tilted fiber gratings

“…In this report, both single and multiple wavelength fiber laser cavities have been demonstrated based on 45° TFG which can induce the polarization effect [6][7]. Besides, pulsed fiber lasers operating at Q-switching or mode locking regime have also been illustrated via the nonlinear polarization rotation (NPR) technique [8][9].…”

Polarization dependent cladding modes coupling and spectral analyses of excessively tilted fiber grating

“…Since proposed, ETFGs have attracted considerable attention in RI sensing applications due to their advantages of high RI sensitivities, narrow bandwidth and low thermal cross-sensitivity [9,10], and many bio-chemical sensors based on ETFGs have also been reported [11][12][13][14]. Apart from great potential in sensing applications, the unique polarization dependent dual peak pairs of ETFGs also make them promising in fiber laser applications, and several wavelength switchable laser schemes have been implemented [15,16]. In spite of many experimental works on ETFGs reported, theoretical analyses about ETFGs, especially about the polarization dependent dual peaks, are rarely testified.…”