Quadratic Non-Linear Optical Properties of the poly(2,5-bis(but-2-ynyloxy) Benzoate Containing the 2-(ethyl(4-((4-nitrophenyl)buta-1,3-diynyl)phenyl)amino)ethanol) Chromophore

Abstract

Excellent quadratic non-linear optical (ONL-2) properties of the poly(2,5-bis(but-2-ynyloxy) benzoate, containing a polar diacetylene as a chromophore, were found. According with the Maker fringes method, oriented polymer films showing an order parameter of ∼0.23 can display outstanding and stable Second Harmonic Generation (SHG) effects under off-resonant conditions (SHG-532 nm). Also, the macroscopic non-linear optical (NLO)-coefficients were evaluated under the rod-like molecular approximation, obtaining: χzzz(2) and χzxx(2) in the order of 280 ± 10 and 100 ± 10 pm V−1, respectively. The mechanical and chemical properties, in addition to the large ONL-2 coefficients exhibited by this polymer, make it a promising organic material in the development of optoelectronic/photonic devices.

Nonlinear Optical Pigments. Two-Photon Absorption in Crosslinked Conjugated Polymers and Prospects for Remote Nonlinear Optical Thermometry

“…From the processing point of view, polymers and polymeric materials appear to be exceptionally versatile as well, as some of them can be prepared in the form of liquid solutions or dispersions but also can be readily processed as powders, fibers, and films, and some selected examples of them can be obtained as single crystals. Accordingly, favorable optical and physicochemical properties of polymers created a fertile niche for investigation of various aspects of their NLO properties, such as electro-optic phenomena, i.e., the linear electro-optic effect (Pockels effect) [15], the quadratic electro-optic effect (optical Kerr effect) [16][17][18], parametric energy conversion in second-harmonic [11][12][13][14][19][20][21] and third-harmonic generation [22][23][24][25][26] variants, and finally the two-photon absorption phenomenon (2PA) [26][27][28][29][30][31], which is at the focus of this paper.…”