中文摘要：

在多模掺镱双包层光纤上，利用相位掩模法直接写制Bragg光栅作为激光器后腔镜，得到多波长激光输出．在室温下，通过调节偏振控制器可以得到稳定的单波长及多波长的激光输出，输出波长范围在1056～1061nm，线宽均小于0．02nm．在25w的976nm激光泵浦下，激光器得到功率为6w的多波长输出．

英文摘要：

A switchable multi-wavelength double-clad fiber laser was demonstrated. Using a phase mask,the fiber Bragg gratings directly in a multimode double-clad Yb^3＋-doped fiber were fabricated as the frequency selective mirror. The single-dual-triple- and four wavelengths output respectively through adjusting the polarization controller were obtained. The wavelength is between 1 056 nm to 1 060 nm and linewidth is less than 0.1 nm. Under a 25 W pump power of 976 nm laser, the maximum output power of the laser is above 6 W in multi-wavelength.