Femtosecond Mamyshev fiber oscillator started by ultra-low power microchip laser seeder at two different wavelengths: a comparison

A 1-W average output power, sub-60-fs femtosecond Mamyshev fiber oscillator was reliably started by a passively Q-switched sub-ns microchip laser generating four-wave-mixing signals in a polarization-maintaining passive fiber, at either 1064 nm or at 1033 nm. We show experimentally that seeding at 1033 nm provides much higher quality pulses with a duration as short as 41 fs and minimal satellites. The evolution toward the gain-managed nonlinear amplification regime clearly takes place when seeding the oscillator closer to the peak gain of the Yb-doped fiber.