We generated the second harmonics of pulses in the far-infrared region (30–55 µm), using the organic salt dimethylamino-4-<i>N</i>-methylstilbazolium tosylate (DAST). We demonstrate that DAST can be used to characterize ultrashort pulses in a spectral region where no other materials are available. To illustrate the need for such characterizations, we show the effects of propagation through air on the shape of ultrashort far-infrared pulses.
© 1998 Society of America
(190.4400) Nonlinear optics : Nonlinear optics, materials
(320.5550) Ultrafast optics : Pulses
(320.7100) Ultrafast optics : Ultrafast measurements
(320.7110) Ultrafast optics : Ultrafast nonlinear optics
Niels A. van Dantzig, Paul C. M. Planken, and Huib J. Bakker, "Far-infrared second-harmonic generation and pulse characterization with the organic salt DAST," Opt. Lett. 23, 466-468 (1998)