Tunable single-polarization single-longitudinal-mode erbium-doped fiber ring laser employing a CMFBG filter and saturable absorber

A Single Longitudinal Mode Fiber Ring Laser Based on Cascaded Microfiber Knots Filter

“…To attain SLM operation, various filters are usually incorporated in the fiber ring cavity. So far, a lot of all fiber filters, such as fiber bragg gratings (FBGs) [7], chirped moire FBGs [8], and a Fabry-Perot interferometer [9] have been inserted into the fiber laser cavity to achieve SLM lasing oscillations. However, several disadvantages including high loss, bulky systems and a risk of system instability still exist due to the multiple cavity filtering components.…”

Stable single-polarization single-longitudinal-mode linear cavity erbium-doped fiber laser based on structured chirped fiber Bragg grating

“…More importantly, the short-length cavity can result in broad spectral linewidth. Another approach is a long-length ring cavity to offer higher output power without special requirements for the gain media [6]. However, since a fiber ring laser usually has a long cavity with closely spaced longitudinal modes, an ultranarrow bandpass filter (BPF) must be incorporated to eliminate multilongitudinal-mode oscillation and mode hopping [7].…”

“…Furthermore, to achieve stable SLM operation, several techniques have been proposed to ensure a long-term stable performance in EDFL, for instance, introducing a passive multiplering cavity or a compound ring resonator composed of a dual-coupler fiber ring to guarantee SLM laser oscillation [9], using an unpumped EDF as a dynamic narrow-bandwidth filter [10], and utilizing selfinjection feedback to control the lasing frequency [11]. At the same time, in order to realize a singlepolarization (SP) fiber laser, several methods have been proposed, such as utilizing polarizationdependent losses of the fiber laser [12], an inline broadband polarizer [6], injection locking [13], and PM-FBG [14].…”

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.…”

“…OSA. Usually, the laser linewidth can be measured by the delayed homodyne method [14] . The characteristic of longitudinal mode is confirmed by a scanning Fabry-Pérot interferometer (FSR= 8.8…”