Attosecond pulses are typically generated using high-harmonic generation, a process that involves the interaction of intense laser light with a gas medium. When a high-intensity laser pulse interacts with gas atoms, it ionizes the atoms and accelerates the free electrons. These electrons then recombine with the parent ions, emitting high-energy photons that form an attosecond pulse. This process is highly nonlinear and requires precise control of laser parameters.
