Tunable erbium-doped fiber ring laser based on thermo-optic polymer waveguide Bragg grating

A tunable erbium-doped fiber ring laser incorporating a tunable thermo-optic polymer waveguide Bragg grating is proposed. Nano-imprinting technique was used to fabricate the polymer waveguide Bragg grating whose reflectivity and 3 dB bandwidth are 25 dB and 0.8 nm, respectively. The polymer waveguide Bragg grating was used as wavelength selective element in the ring laser system and the center wavelength can be tuned by controlling the electrical power on the micro-heater. The fabricated tunable laser exhibits an output of 4.1 dBm, side-mode suppression ratio of 55 dB, 3 dB bandwidth less than 16 pm, and wavelength tuning range of 8.4 nm.