Synthesis and Characterization of Sterically Stabilized Second-Order Nonlinear Optical Chromophores

Electro-optic properties of a guest-host system containing a phenothiazine-based chromophore: Effect of the chromophore density on the macroscopic optical nonlinearity

“…The synthesis of 2-cyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TCF) was synthesized following the known procedure. 11 Synthesis of 10-hexyl-10H-phenothiazine (1): Sodium hydride (14.4 g, 0.36 mol) was dissolved in dried dimethylformamide (DMF, 200 mL) at 0 o C. Phenothiazine (59.7 g, 0.3 mol) in DMF (100 mL) was added dropwise into the mother solution and stirred for one hour. Then, 1-bromohexane (59.4 g, 0.36 mol) in DMF (50 mL) was also added dropwise over 30 min and the reaction mixture was kept stirring at room temperature for 12 hrs.…”

“…Particularly, 2-cyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TCF) was well adopted as a strong electron acceptor to induce significantly high dipole moment (μ), first-order molecular hyperpolarizability (β), and their product (μβ). [7][8][9][10][11] Since acentric ordering of dipolar chromophores is required to exhibit second-order nonlinearity, usually electrical poling is employed to the NLO sample film. Among many kinds of host amorphous polymer, polycarbonate (APC, poly(bisphenol A carbonate-co-4,4'-(3,3,5-trimethylcyclo hexylidene) diphenol, T g = 202 o C) behaves as a quite rigid polymer binder to retard the dipolar relaxation after poling process.…”

“…2-Cyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TCF) was employed as a strong electron acceptor to induce charge transfer complex. [7][8][9][10][11] In order to investigate the macroscopic nonlinearity of the chromophores, we introduced the chromophore into the amorphous polycarbonate with various doping concentrations. The samples were poled to measure the electro-optic coefficient at 1300 nm.…”

Preparation and nonlinear optical properties of hybrid sol–gel films doped with triphenylamino-substituted chromophores

“…Attention has been essentially focused on dipolar molecules for several decades in the quest for improving NLO properties [2e5]. Recent progresses include the exploration of ring locked isophorone-bridge chromophores (CLD series), which exhibit high b values and the EO device based on them shows commercial promise [3,4]. But the rigid isophorone-bridge also causes crystallization and solubilization problems [5].…”

Enhancement of Effective Second-Order Nonlinearity in Poled Polymers by Introducing the Chromophores With Low Ground State Dipole Moment

“…A considerable number of results have been achieved in the design of the donor-acceptor functionalized chromophores, for instance, Λ-type chromophores, 5 organic and organometallic octupolar chromophores 6-8 and a series of novel and extremely high first hyperpolarizabilities (β) chromophores. 9,10 In our group, the X-type chromophores have also been designed and synthesized successfully. 11,12 However, these chromophores possess larger ground state dipole moments (µ g ) than 7.5 D. It may be beneficial in aligning the chromophore better in poled polymers, but it can also inevitably lead to large electrostatic repulsion to form anti-parallel microstructure between these high µ g chromophores, which limit the available chromophore loading level and reduce the order parameters of the poled polymers.…”