Fast revision of spectral phase masks for femtosecond pulse shaping with neural network

A fast revision system to redesign spectral phase-only masks by neural network without any iterative calculation is proposed and numerically demonstrated. In this system, to maintain the constant shaped pulse waveform separate approaches are applied against the amplitude change and the phase change of an input pulse in spectral domain. When the input power spectrum varies, a neural network produces a new phase-only mask, which compensates the change in the input spectrum amplitude. Once the neural network is trained, its use in practice is essentially instantaneous, typically requiring less than a second.