Combining comb-filters based on tapered fibers for selective lasing performance in erbium-doped fiber lasers

In this work, we report a new method to make a selection between tunable and multi-wavelength switchable operation in an erbium-doped fiber laser. The selective lasing performance is based on two concatenated comb-filters built on tapered optical fibers. By properly adjusting curvature applied to the comb-filters, the lasing wavelength can be selective in two ways: continuous tuning or generating multi-wavelength laser oscillation. The laser exhibits an optical signal to noise ratio of ~30 dB and power stability below 1 dB at room temperature. The main achievement of this proposal is that the laser can be operating independently between tuning and multi-wavelength lasing with a high stability employing a reliable and low-cost comb filters.