Time and wavelength resolved nonlinear optical spectroscopy of a polydiacetylene in the solid state using picosecond dye laser pulses

Degenerate four‐wave mixing of tunable dye laser pulses in good optical quality single crystal platelets of poly bis(p‐toluene sulfonate) of 2, 4‐hexadiyne‐1, 6 diol (PTS) polydiacetylene was used to measure the spectral and temporal dependence of the material’s third order nonlinear optical susceptibility χ(3). For the wavelength range measured ‖χ(3)‖ varied from 9×10−9 esu at 6515 A to 5×10−10 esu at 7015 A. The material’s response time was determined to be less than the optical pulse width (≂6 ps) over this wavelength range.