Single-Frequency Erbium Laser Based on Random Distributed Feedback Based on Inhomogeneities of Phase Mask.

A single-frequency erbium laser with a radiation wavelength of about 1555.8 nm with random distributed feedback, which is implemented due to inhomogeneities of phase mask resulting from recording of a single high-reflectance fiber Bragg grating, is presented. The spectrum of such a grating contains asymmetric side resonances located predominantly in the long-wavelength spectral region. At the wavelength of one of the dips separating the resonances, single-frequency lasing with a linewidth of about 1 kHz is observed at a maximum output power of 0.74 mW obtained at a pump power of 540 mW. The power and spectral characteristics of the laser are comparable with those of a regular laser with distributed feedback. [ABSTRACT FROM AUTHOR]