All-fiber single-longitudinal-mode narrow linewidth fiber ring laser with cylindrical vector beam output

Abstract

A single-longitudinal-mode (SLM) fiber ring laser with cylindrical vector beam (CVB) output is experimentally demonstrated. Mode selection and spectrum filtering are achieved by introducing a two-mode fiber Bragg grating (TM-FBG) as an output mirror simultaneously. The SLM operation is obtained by using a compound ring cavity laser structure together with an un-pumped EDF acting as a saturable absorber. The fiber laser operates at a single wavelength of 1545.99 nm with a 20 dB linewidth of about 7.1 kHz and an optical signal to noise ratio of more than 68 dB. Through adjusting the intra-cavity polarization controllers, stable narrow linewidth radially and azimuthally polarized CVBs are both obtained.

Generation of polarization and phase singular beams in fibers and fiber lasers

“…8(a)] at peak 1, the fundamental mode was reflected back and the desired high-order mode was exported from the TMFBG. 111 Based on the offset-spliced fiber and TMFBG, Sun et al constructed the figure-8 fiber laser, 108 linear-cavity fiber laser, 106,112,113 and ring fiber laser 109,114 to directly generate RPB and APB. In the temporal domain, these cylindrical vector fiber lasers were capable of delivering continuous waves, microsecond pulses, nanosecond pulses, and picosecond pulses.…”

One KHz Order Narrow Linewidth Fiber Laser Using Rayleigh Backscattering Mechanism in an Additional Piece Optical Fiber

“…It requires strong pump power and a long fiber length, which induces colossal loss. Jiang et al [16] demonstrated a switchable single longitudinal mode (SLM) narrow linewidth fiber laser with cylindrical vector beam (CVB) output. At 1543.35 nm and 1544.38 nm, the OSNR is higher than 60 dB, and the laser linewidth is 5.7 KHz and 6.8 khZ, respectively.…”