We report on a 400 nm broad-band type I frequency doubling in a non-collinear geometry with pulse front tilted and chirped femtosecond pulses (l0 = 800 nm, FTL pulse duration ~ 45 fs). With moderate power densities (2 to 10 GW/cm2) thus avoiding higher-order nonlinear phenomena, the energy conversion efficiency was up to 65%. Second-harmonic pulses of Fourier transform limited pulse duration shorter than the fundamental wave were generated, exhibiting a good beam quality and no pulse-front tilt.