Watt-level femtosecond praseodymium-doped fluoride fiber amplifier at 1300 nm

Watt-level chirped pulse amplification based on praseodymium-doped fluoride fibers (Pr³⁺:ZBLAN) has been demonstrated. We have successfully amplified the 1300 nm dispersive wave from a highly nonlinear fiber to an average power of 1.33 W using a three-stage Pr³⁺:ZBLAN amplifier. The average power is more than five times higher than that ever achieved with any praseodymium-doped fiber amplifier. The nonlinear phase distortion in the third stage of the amplifier was compensated by adjusting the distance of the compressor based on a pair of gratings. The duration of the compressed pulse was 367 fs, while the Fourier-transform limited pulse duration was 301 fs.