Multi-wavelength switchable fiber laser

We demonstrate a switchable multi-wavelength ring fiber laser based on cavity-resonance-activation. It is obtained by addressing the suitable mode-locking frequency of a multi-length laser cavity formed by successive fiber Bragg grating mirrors with different reflecting wavelengths. In the experiment, we used for the reflection sampled fiber Bragg gratings (SFBG). Each SFBG has several equally spaced reflection lines, which determine the lasing wavelengths. The RF modulation frequencies that correspond to the various cavity lengths for the different SFBGs are slightly different. At each wavelength, the pulses consist of several sidebands spaced by the frequency modulation or its harmonics. The laser was shown to operate either in a single switchable wavelength, with its sidebands, or simultaneously at several wavelengths. Such lasers can be useful in optical communication systems and fiber sensors.