Background suppression in synthesized pulse waveform by feedback control optimization for flatly broadened supercontinuum generation.

We demonstrate a method of background component suppression of synthesized pulses for flatly broadened supercontinuum (SC) generation. An adaptive pulse shaping in frequency domain achieved a 26 dB contrast between pulse center and background level in auto-correlation trace by combining two fitness functions during feedback-controlled pulse shaping. The pulse was used as a SC pump, and the spectral peak of the SC at the pump wavelength was suppressed by 5 dB using the combination scheme. Simulation results show that the phase spectra control is required to be within ± π/100 rad to suppress the spectral peak below 3 dB. The results show that adaptive pulse shaping is required to improve SC flatness due to the small mismatch tolerance.