  In this work, we have developed a method to generate ultra-short pulses below
the Fourier limit, extending the concept previously worked in reference 1 for
generating sub-diffractive Gaussian beams. Alternatively, we introduce new
alternatives based on a temporally non-symmetrical interference to narrow
ultrashort pulses allowing, sub-Fourier scales. The experimental setup scheme
is simple and versatile being able to work with high-power laser sources and
ultra-short pulses with a broad bandwidth at any central wavelength. The
results presented, are promising and help to enlighten new routes and
strategies in the design of coherent control systems. We glimpse they will
become broadly useful in different fields from strong field domain to quantum
information.
