Novel promising crosslinkable tricyanopyrroline polymeric electro-optic materials

Abstract

A tricyanopyrroline chromophore with methacrylate reactive group was synthesized to fabricate the side chain (polymer 1) and crosslinkable (polymer 2) EO (electro optic) polymers with enhanced electrooptical tensor coefficients. These type of polymers have demonstrated the large EO coefficients with values of 29 pm/V and 25 pm/V at wavelength 1,310 nm, respectively. Compared with polymer 1, t polymer 2 had demonstrated a better stability of polar structure. The thermal stability of polar structure was improved for about 100°C. The temperatures of poling and crosslinking processes were compatible in polymer 2, which allowed obtaining the EO films with improved features. The experimental results have been interpreted with the aid of quantum-chemical calculations.

Preparation of Main-Chain Polymers Based on Novel Monomers with D−π–A Structure for Application in Organic Second-Order Nonlinear Optical Materials with Good Long-Term Stability

“…Second-order nonlinear optical (NLO) materials based on organic polymer and small functional molecules have attracted widely attention. These NLO materials have been identified to have potential applications in high-speed electro-optical (EO) conversion devices, such as frequency converters, optical switches and EO modulators. − These organic polymeric NLO materials have also shown prominent merits in EO effect, response time, bandwidth, and driving voltage, over their inorganic counterparts of lithium niobate. − For decades, researchers have been encouraged to synthesize many NLO polymers with large EO coefficients, high optical and thermal stability, as well as good optical transparency to satisfy the requirements of practical applications. − However, the use of NLO polymers remains problematic for two primary reasons: (1) it is difficult to translate efficiently the large first order hyperpolarizability of organic chromophores into large macroscopic EO coefficients of the polymers; (2) organic EO polymers suffer from poor long-term stability. The cause of these deficiencies is that the organic chromophores with large dipole moment improve the intermolecular interactions among the chromophore molecules, and these can cut down the poling efficiency. − Originally, researchers from the group of Jen and Dalton introduced site isolation chemical groups around the chromphores, which can efficiently reduce the interactions. , Though many EO polymers with larger macroscopic EO coefficients have been reported in host–guest systems based on this theory, the problem of long-term stability has not yet been resolved.…”

Novel poly(aryl ether ketone) with electro-optic chromophore side chains for light modulators

“…The large modified group confirmed the sufficient distance between the chromophores and improved the solubility of the chromophore. The synthesis of chromophore TCF-G and TCP-G has been reported in our earlier papers [28,38]. They are both synthesized by a Knoevenagel condensation reaction [17,19].…”

“…For the second system, the design of cross linkable groups is very difficult. Both of the cross linking conditions and the chemical stability of the chromophores in the cross linking process should be considered [27][28][29][30]. Fortunately, a compromised method was proposed: nonlinear optical chromophores were attached to the polymers with high glass transition temperatures as the side chain [31,32].…”

Nonlinear optical chromophores based on Dewar's rules: enhancement of electro-optic activity by introducing heteroatoms into the donor or bridge

“…[2][3][4][5][6] As the core component of EO materials, the design and preparation of NLO chromophores have been turned into a hot research spot in the area of organic EO materials. [7][8][9][10][11] To realize the application of devices, NLO chromophores should be required to possess several properties: large first-order hyperpolarizability (b), low optical loss at operation wavelength, thermal stability and long-term stability of polar order. Therefore, much greater effort has been devoted to the rational design of chromophores with not only high first-order hyperpolarizability but also good thermal and photochemical stabilities, and in addition, good solubility and compatibility with the polymer matrix.…”

“…Therefore, much greater effort has been devoted to the rational design of chromophores with not only high first-order hyperpolarizability but also good thermal and photochemical stabilities, and in addition, good solubility and compatibility with the polymer matrix. [12][13][14][15] It is a well-established fact that the conjugation length and the donor/acceptor strength of these D-p-A type push-pull chromophore molecules can have dramatic influences on their second order nonlinear responses. 16,17 A majority of high performance NLO chromophores up to now can be divided into three blocks: an electro-donor (typical alkyl aniline), a pi-bridge (isophorone or heterocyclic rings) and a strong electro-acceptor.…”