Single-longitudinal-mode Brillouin fiber laser incorporating an unpumped erbium-doped fiber loop

Abstract

A long-cavity single-longitudinal-mode (SLM) Brillouin fiber laser is firstly demonstrated by utilizing an unpumped Erbium-doped fiber (EDF) loop. The utilized EDF enables to form a self-induced ultra-narrow grating filter, and thus guarantees the SLM operation.

Single Longitudinal Mode Brillouin Fiber Laser With Cascaded Ring Fabry–Pérot Resonator

“…However, because of length limitation of SLM operation, it is difficult to improve the threshold power and linewidth. Then, BFL incorporating long fiber length (500 m) Manuscript high nonlinear fiber (HNLF) and an unpumped Erbium-doped fiber (EDF) loop (10 m) [14] which is regarded as a selfinduced fiber Bragg grating (FBG) filter with an ultra-narrow bandwidth is proved. However, accurate power control is necessary to make the FBG reach proper pass-band bandwidth and 500 m HNLF is easy to generate high-order Stokes lines [15].…”

980 nm narrow linewidth Yb-doped phosphate fiber laser

“…A narrow linewidth ring laser always exhibits a long cavity length, so its longitudinal interval is extremely narrow, which is easy to arouse mode-hopping. Several methods have been investigated and reported to be implemented stable narrow linewidth fiber lasers by suppressing the multi-longitudinal-mode operation and mode hopping for example inserting an unpumped doped fiber which acts as a saturable absorber, an intra-cavity Fabry-Pérot etalon in the fiber cavity or a fiber loop which works as a filter etc [11][12][13][14] . However, short length linear cavity fiber lasers have recently demonstrated the potential to meet all the requirements thanks to their compactness, simplicity, and robustness.…”

“…In 2013, Shanhui Xu et al attained a 100 mW 1083 nm narrow linewidth fiber laser with an output linewidth of less than 2 kHz based on a 1.8 cm long home-made Yb-doped phosphate fiber which was spliced with a pair of FBGs [12] . In same year, Shupei Mo et al presented a compact linearly polarized narrow linewidth fiber laser at 1014 nm based on a 5 mm long home-made Yb-doped phosphate fiber.…”

All-optical spectral linewidth reduction of lasers for coherent optical communication

“…To resolve this problem, we first insert a high-fineness combined fiber ring (FR) into the cavity to expand the spacing of the resonant frequencies and ensure the single-longitudinalmode (SLM) output as well as the low insertion loss. Then by applying a piece of unpumped erbium-doped fiber (EDF) as a saturable absorber, mode hopping between the resonant frequencies, which are dominated by the FR, can be eliminated [13,14]. As a result, the ultranarrow linewidth and single-frequency output can be secured finally.…”

“…Moreover, no other noise components are observed for frequencies up to 200 MHz. To further mitigate the RIN peak at ∼9 MHz, one possible method is to use longer-length unpumped EDF, while it lead to the larger insertion loss of the proposed scheme [13].…”