An optical pulse generation scheme based on an ultra-short chirped seed pulse generator followed by a dual-stage fiber-based nonlinear pulse processing stage is proposed and demonstrated experimentally. After phase modulation and linear-chirp compensation, optical seed pulse with a duty cycle of 9.8% and an obvious pedestal is obtained. By soliton compression and Mamyshev reshaping, a pedestal-free optical pulse with a duty cycle of 2% and an extinction ratio of 27 dB is achieved. The optical pulse source is further applied in a 16×25-Gb/s on-off keying optical time-division multiplexing transmitter.