Ultrabroadband second-harmonic generation in organic and inorganic thin crystals

Organic thin crystals of 2-methyl-4-nitroaniline (MNA) have been used to frequency double simultaneously all components of a broadband continuum using a non-phase-matched configuration. A 1 μm sample of MNA permits to convert, in a single pulse, wavelengths in the band 600-1400 nm to the 300-700 nm band. Using the same technique, we also evidence the remarkably large bandwidth of a 100-μm-thick KDP, when used in the wavelength noncritical phase-matched region centered around 1.03 μm. The conversion efficiencies of the 1-μm-thick MNA sample and of the 100-μm-thick phase-matched KDP crystal are shown to be comparable. The results are of interest to the processing and measurement of femtosecond pulses.