Noise-like pulses with a 14.5 fs spike generated in an Yb-doped fiber nonlinear amplifier.

We demonstrate noise-like pulses with a 14.5 fs spike generated in an Yb-doped fiber nonlinear amplifier after compression, while the pedestal has a width of 3.70 ps. This Yb-doped fiber nonlinear amplifier is seeded by dissipative solitons. With an average output power of 5 W, the single pulse energy is approximately 200 nJ at a repetition rate of 24.65 MHz. Mathematical research based on the coupled nonlinear Schrödinger equations about the generation and the compressibility of the noise-like pulses is also carried out.