Disclosed is a method including: (i) dispersing frequency components of an input EM waveform along a first direction with each frequency component spatially extended along a second direction different from the first direction; (ii) setting an amplitude for an output portion of each of the spatially extended frequency components; and (iii) combining the output portions from the different frequency components to produce a temporally shaped output EM waveform, wherein setting the amplitude of each output portion comprises diffracting a corresponding input portion for the spatially extended frequency component along the second direction into different diffraction orders, wherein the combined output portions correspond to a common diffraction order. A system for performing the method is also disclosed.