Photorefractive amorphous glass bearing the tricyanopyrroline chromophore and its properties measured at 830 nm

We report the photorefractive properties of near IR-sensitive amorphous molecular glasses containing the tricyanopyrroline (TCP) chromophore. Second-order nonlinear optical chromophores bearing the TCP acceptor were synthesized to improve the optical nonlinearity and the infrared sensitivity via an intramolecular charge transfer complex. 2-(l-Allyl-4-{4-[bis-(2-ethyl-hexyl) -amino]phenyl}-3-cyano-5-oxo-l,5-dihydro-pyrrol-2-ylidene)-malononitrile (DEHA-TCP) and 2-[3-cyano-4(4-dibutylamino-phenyl)-5-oxo-l-propyl-l,5-dihydro- pyrrol-2-ylidene]-malononitrile (DBAP-TCP) have relatively high figures of merit compared to other conventional chromophores. The photoionizable TCP chromophore was employed to fabricate thick film samples in the presence of (2,4,7-trinitro-fluorenylidene)malononitrile (TNFM). A two-beam coupling experiment at 830 nm provided clear evidence for asymmetric energy transfer phenomena and a reasonably high gain coefficient.