Chirped and phase-sampled fiber Bragg grating for tunable DBR fiber laser.

Chirped and phase-sampled fiber Bragg gratings are fabricated and used as reflectors in tunable DBR fiber laser for the first time. By controlling the phase of each sampling section, sampled Bragg gratings (SBG) with different channel spacing can be obtained using only a single chirped phase mask. A 30nm-wide tunable Erbium-doped fiber (EDF) laser is designed and experimentally demonstrated by utilizing the vernier effect of two such SBGs with channel spacing of 3.2nm and 3.6nm, respectively. The lasers’ output power of different channels is almost identical (difference less than 1dB) within the tunable range.