We exploit the high second-order susceptibility of the organic crystal <i>N</i>-(4–nitrophenyl)-L-prolinol to accomplish, through a cascaded second-order process, wavelength conversion of a signal pulse (from 1.16 to 1.14 µm) under the action of a pump pulse (at 1.15 µm). In a 2.8-mm-thick crystal, wavelength conversion with unit gain was obtained with a pump peak intensity as low as 9 MW/cm<sup>2</sup> . At low intensities, in the limit of negligible conversion where the cascading effect can be described through an effective third-order susceptibility, we derive |<sub><i>x</i></sub><sup>(3)</sup><sub>eff</sub> | ≈ 2.4 × 10<sup>-17</sup> m<sup>2</sup>/V<sup>2</sup>, which is ~10<sup>2</sup> larger than the nonresonant <sub><i>x</i></sub><sup>(3)</sup> of conjugated polymers or semiconductors.
© 1998 Optical Society of america
G. P. Banfi, P. K. Datta, V. Degiorgio, G. Donelli, D. Fortusini, and J. N. Sherwood, "Frequency shifting through cascaded second-order processes in a N-(4-nitrophenyl)- L-prolinol crystal," Opt. Lett. 23, 439-441 (1998)