Research on switchable and tunable multi-wavelength erbium-doped fiber laser

Abstract

A multi-wavelength erbium-doped fiber laser with switchable output wavelength and tunable wavelength interval is designed and realized. The ring cavity structure is adopted. There are two independent sub-cavities in the ring cavity. One sub-cavity uses FBG-Sagnac ring filter as the frequency selection element, and the other sub-cavity uses fiber Bragg grating (FBG) as the frequency selection element. The performance of the FBG-Sagnac loop filter is analyzed by transmission matrix method and MATLAB simulation, and a dual-path erbium-doped fiber laser is built. At room temperature, by changing the state of optical attenuator and polarization controller, single, double and three wavelength outputs are obtained. In the mode of outputting a wavelength, the laser can realize free switching among the output wavelength of 1550.0 nm, 1550.8 nm and 1551.6 nm. In the mode of dual wavelength output, the output wavelength interval can be switched between 0.8 nm and 1.6 nm. In the mode of outputting three wavelengths, the wavelength interval of the output laser is 0.8 nm, it can be realized to meet the requirements of wavelength division multiplexing. In the stability test, the experimental results show that the laser has good stability.