Effects of laser spectrum on amplified spontaneous emission prepulse duration in chirped pulse amplification lasers

We demonstrate experimentally and theoretically that prepulse duration via amplified spontaneous emission (ASE) is strongly related to laser spectra in chirped-pulse amplification lasers due to pulse compressor dispersion. Although ASE prepulses overlap with stretched main pulses, we show that ASE prepulse duration can be reduced by injecting a laser pulse with a short center wavelength.