Mode-Locked Erbium-Doped Fiber Lasers Using 45° Tilted Fiber Grating

Abstract

Abstract-We have systematically studied the 45° tilted fiber grating (45TFG) as a functional device for Erbium doped fiber laser (EDFL) mode locking. A number of 45TFGs with different polarization dependent loss (PDL) have been fabricated. Mode locked Erbium doped fiber laser using these devices have been characterized in terms of threshold, pulse duration, signal to noise ratio (SNR), and spectral width. Our results show that a 45TFG with higher PDL could achieve better laser results. By using a 45TFG with 24dB PDL, the mode locked laser has 8.1% conversion efficiency and a threshold of 200mW.

23 MHz widely wavelength-tunable L-band dissipative soliton from an all-fiber Er-doped laser

“…As proved in previous studies [27][28][29], the 45°TFG have been considered as an effective infiber polarizer, because it can compel s-light out of grating while allow p-light pass with low loss. In order to characterize the features of 45°TFG, a vector optical analyzer incorporating a tunable laser with the operating range between 1525 nm to 1610 nm is employed.…”

“…To alternate the PDL response of the 45°TFG, we simply tune the tilted angle of the phase mask by rotating a goniometer by less than 1°. Clearly, compared to former works [27][28][29], the peak of PDL profile locates at 1593 nm is 48.4 dB, which means that the 45°TFG is designed to operate exclusively at L-band and can function as an effective polarizer to achieve NPR mechanism at the chosen region [30]. Also, one can find that there are notable spectral ripples arising from the mismatching refraction index between cladding and radiation mode, which technically do not affect the performances of the laser.…”

Excessively tilted fiber grating based Fe3O4 saturable absorber for passively mode-locked fiber laser

“…The maximal PER of Fe 3 O 4 deposited Ex-TFG is only 5.6 dB and the PER is even less than 2 dB at the mode-locking central wavelength of 1595 nm. To initiate NPR modelocking with such low PER in the fiber laser, high nonlinearity is needed which can be realized by using hundreds of meters long high nonlinear fibers and high pump power [42,46]. Considering that the cavity length in this experiment is only 13 m without any high nonlinear fibers and the mode-locking threshold is only 60 mW, it is not sufficient for initiating NPR mode-locking with the low PER.…”

64-fs L-band Pulse Generation by an All-Fibre Er-Doped Laser

“…A fibre coupler after the EDF taps 40% of laser power out of the cavity for measurement. In our laser setup, the relatively long EDF length permits to acquire 1.6 m emission, while the strong PDL of the Brewster fibre grating favours the generation of ultrashort pulses [16] . The Brewster fibre grating is UV inscribed into a length of hydrogenated SMF using the standard phase mask scanning technique.…”