A TUNABLE NARROW-LINEWIDTH Er-DOPED FIBER RING LASER BASED ON TUNABLE FIBER BRAGG GRATINGS

摘要

A tunable narrow-linewidth Er-doped fiber ring laser using tunable fiber Bragger gratings (TFBGs) is proposed and demonstrated. The TFBG is fabricated with a strain-induced uniform FBG, which acts as an excellent reflecting mirror. By putting longitudinal strain to the TFBG, an approximately continuous tunable lasing output is obtained, the wavelength tunable range covers 8.00 nm (from 1543.5643 to 1551.5108 nm), and the tunable resolution is 1.92 nm/mm. A repeated testing result shows that the linewidth of the laser is stable and less than 0.01 nm, and the side-mode suppression ratio is better than 50 dB. Moreover, an array waveguide grating is utilized for wavelength preselecting, and a 50-km transmission performance of the proposed laser is tested experimentally under a 10 Gb/s modulation rate.