In past years, there have been many attempts to produce tunable light sources with short pulse width, which would be very valuable for spectroscopic studies in material science and quantum electronics. Optical parametric generation has many features such as amplification, wavelength conversion, and pulse-width narrowing due to a nonlinear propagation process. Therefore, parametric generation pumped by short light pulses has the potential to generate broadly tunable optical pulses from visible to near-infrared without using an optical cavity. The wavelength of optical pulses generated by parametric superfluorescence can be changed by simply varying the phase-matching condition. By using shorter pulse width pumping light, parametric superfluorescence output pulses with subpicosecond pulse width is possible. Here, we show the efficient tunable parametric generation in KTiOPO4, (KTP) crystals pumped by 1 ps pulses. Obtaining sufficient gain requires pump pulses with high peak intensity, so an amplified mode-locked dye laser is used as a pump source. KTP crystals are suitable because of their large nonlinear optical coefficients and high optical damage thresholds. In this experiment, tunable short pulses from 0.93 to 1.59 micrometer are obtained. The output pulse energy and the conversion efficiency at the degenerate wavelength are 0.85 micro J and 9.9%. By utilizing the pulse-width narrowing effect, signal pulses with pulse duration of 320 fs and the idler pulses with pulse duration of 250 fs can be obtained from 550 fs pump pulses.
