Characteristics of a Brillouin-erbium fiber laser based on Brillouin pump preamplification

Abstract

A single-mode Brillouin-erbium fiber laser (BEFL) is realized using only a 5 m single-mode fiber (SMF) as Brillouin gain medium, which to our best knowledge is the shortest SMF ever used to construct a BEFL. The Brillouin pump (BP) preamplification technique is adopted using a bidirectionally amplified erbium-doped fiber amplifier inside the BEFL cavity. This BEFL presents a high optical signal-to-noise ratio (~40 dB), a large output power (~10 mW), and a low 980 nm pump threshold (~15 mW). Experimental results indicate that this threshold increases with the BP power. Two lower and upper BP thresholds exist for the BEFL onset and turnoff, respectively, for a fixed 980 nm pump power. Moreover, the output power of this BEFL increases linearly with the 980 nm pump power at the same slope efficiency of ~10% for various BP powers, but decreases linearly with the BP power at the same slope efficiency of ~-26% for various 980 nm pump powers.

Widely tunable ultra-narrow linewidth single-longitudinal-mode Brillouin fiber laser with low threshold

“…As a result of the unflattened gain profile of the erbium amplification, the peak powers of the output signals are not equal within the tuning range. It is clearly seen that the OSNRs of all the laser output are higher than 70 dB, which is higher than those reported previously [13][14][15][16][17].…”

“…The high threshold demands special requirements of the EDFA, increasing the cost of the system and reducing the practicality. BFLs with EDFA located in the cavity can reduce the threshold to 10 mW level, but the pump wavelength has to match the self-lasing cavity mode, which limits the tunability [13,14]. Moreover, it inevitably introduces amplified spontaneous emission noise and reduces the optical signal-to-noise ratio (OSNR).…”

Low-Threshold, Single-Mode, Compact Brillouin/Erbium Fiber Ring Laser

“…However, these BEFLs require high pump threshold ( ) due to the serious attenuations of the special fibers, and the laser output power is also limited by the resonator losses. Recently, we have reported a low-threshold single-mode BEFL based on Brillouin pump preamplification [17]. Only 5-m SMF is used in this BEFL, and the total cavity length is about 10 m. Single-mode operation is ensured since only one longitudinal mode is allowed in the SBS gain spectrum.…”

“…The conclusions are summarized in Section VI. Without BP, this fiber laser is only a free-running EDFL [17]. The injection of BP excites SBS in the EDF.…”

Multiwavelength narrow linewidth erbium-doped fiber laser based on FP-LDs

“…In order to reduce the gain saturation and suppress the mode competition, different approaches have been proposed to realize multiwavelength oscillation at room temperature in EDFLs. These include the introduction of polarization hole burning (PHB) effect [1][2][3], frequency shifters [4,5], wavelength or intensity dependent loss [6,7], and various nonlinear effects such as four-wave mixing [8,9] or stimulated Brillouin scattering [10,11] in the laser cavities. Other methods by incorporating in the laser cavity a length of multimode fiber or a multimode fiber Bragg grating [12,13], employing specially designed erbium-doped fibers [14] or cavity structures [15] were also reported.…”