Ultrafast nonlinear refraction inintegrated Fabry-Perot etalon containingpolydiacetylene

Abstract

A nonlinear integrated Fabry-Perot etalon containing poly-1,6-dicarbazolyl-2,4-hexadiyne (poly-DCHD) nanocrystals has been fabricated. Time-resolved fringe shifts following picosecond excitation at 645 nm are monitored with a broadband white-light-continuum probe. The shift towards shorter wavelengths indicates a negative refractive index change. The magnitude of the refractive cross-section is found to be 1.6 × 10–21 cm3, at a wavelength of ~700 nm, suggesting that polydiacetylene nanocrystal thin films are well suited for Fabry-Perot based all-optical switching devices.