Current conception of attosecond pulse is based on Fourier optics and refers to an electromagnetic pulse with a broad. homogeneous weight Fourier spectrum. Its preparation/generation is along an indirect route in which the output of commercial available μ m-level wavelength laser is “processed„ by elaborately designed optics medium allowing high-order harmonics effect... https://www.roneverhart.com/WesAudio-ng76-Analog-FET-1176-Style-Compressor-p14718/