A wavelength-tunable fiber laser based on a twin-core fiber comb filter

A wavelength-tunable fiber laser based on a twin-core fiber (TCF) comb filter is proposed and demonstrated. The TCF comb filter is fabricated by splicing a 0.85 m long TCF between two standard single mode fibers (SMFs) and with exhibits a good linear strain characteristic with a sensitivity of 1.23 pm/με. The wavelength of the laser can be linearly tuned from 1558.04 nm to 1553.62 nm by applying an axial strain to the TCF comb filter. The optical signal-to-noise ratio (OSNR) of the fiber laser reaches 45 dB. The 3 dB bandwidth is 0.02 nm. The fluctuation of the laser peak in the output power and the wavelength is less than 0.5 dB and within 0.05 nm, respectively. The fiber laser has the advantages of having a simple structure and stable operation under room temperature.

► A wavelength-tunable fiber laser based on a twin-core fiber comb filter is proposed and set up.
► TCF comb filter is fabricated by splicing a 0.85 m long TCF between two standard single mode fibers.
► TCF comb filter exhibits a good linear strain characteristic, and its sensitivity is 1.23 pm/με.
► Laser wavelength can be linearly tuned from 1553.62 to 1558.04 nm by changing the axial strain.
► The optical signal-to-noise ratio of the fiber laser reaches 45 dB and its 3 dB bandwidth is 0.02 nm.