Development of Femtosecond Laser Based on an Erbium-Doped Fiber

A high-power femtosecond Er-doped fiber ring laser is developed and investigated. Self-starting passive mode locking is obtained with nonlinear polarization evolution in optical fibers. The spectral width of the output pulses is about 53 nm at a mean wavelength of 1545 nm; the minimum pulse width is about 97 fs at a pulse repetition rate of 76.65 MHz. We use a 976 nm pump diode laser with ex-fiber power of 935 mW to obtain an average output power of 261 mW with a 27.9% pump-to-signal conversion efficiency.