1.94 μm switchable dual-wavelength Tm3+ fiber laser employing high-birefringence fiber Bragg grating

A 1.94 mu m switchable dual-wavelength Tm3+ fiber laser employing two high-birefringence fiber Bragg gratings (HB-FBGs) is demonstrated. The polarization hole burning effect enhanced by the HB-FBG is first observed and adopted to guarantee stable dual-wavelength operation in the spectral region near 2 mu m at room temperature. The wavelength spacing between the dual lasing wavelengths is 0.81 nm. The polarization states of the dual-output lasers are orthogonal. By adjusting a polarization controller, a single-wavelength mode operating at one of the dual wavelengths can be selected. The side-mode-suppression ratio of each laser can be greater than 60 dB. The power fluctuation measurement at both operating wavelengths shows that this Tm3+ fiber laser has good stability. (C) 2013 Optical Society of America