Polymeric electro-optic materials: optimization of electro-optic activity, minimization of optical loss, and fine-tuning of device performance

Abstract

Translation of the large molecular hyperpolarizability of chromophores into large macroscopic electro-optic activity by electric field poling of chromophore-containing polymers is opposed by molecularshape-dependent intermolecular electrostatic interactions. Modification of chromophore structure (shape) to minimize the deleterious effect of such interactions leads to significant improvement in electro-optic activity. Drive voltage requirements for polymeric modulator devices are reduced to values ranging from 0.7 to 5 V. Optical loss of electro-optic polymer materials, at the communication wavelengths of 1.3 and 1.55 m, is defined by C-H, O-H, and N-H vibrational absorptions and by scattering from index of refraction gradients in the material. The former are significantly reduced by partial deuteration and halogenation to values slightly less than 1 dB/cm. A major source of optical loss encountered in the utilization of polymeric electro-optic modulator devices is coupling losses associated with the mode mismatch between silica fiber waveguides and polymeric modulator waveguides. Recently, alternative coupling strategies based on utilization of tapered transitions and vertical transitions have dramatically reduced coupling losses. Total insertion losses comparable to those for lithium niobate devices are realized. Finally, a phototrimming technique is developed that enables fine-tuning of the performance of circuit elements such as power splitters. © 2000 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(00)

Science and technology of perfluorocyclobutyl aryl ether polymers

“…114,115 To achieve wide spread commercial use of electro-optic (EO) applications, NLO materials must have low dielectric constants, constant refractive index over wide wavelength (telecommunications) and temperature ranges, high dipole (l) and hyperpolarizable (b) chromophores, longterm thermal stability, low attenuation, and be processable for the preparation of photonic devices. [116][117][118][119] PFCB aryl ether polymers encompass excellent properties suitable for EO applications. Incorporating second-order NLO chromophores into PFCB aryl ether polymers gives the composite material high EO coefficients, low optical loss, high glass transition temperatures, and good processability.…”

Heterocyclic Nonlinear Optical Chromophores Composed of Phenothiazine or Carbazole Donor and 2-Cyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran Acceptor

“…Particularly, 2-cyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TCF) was well adopted as a strong electron acceptor that induces significantly high dipole moment (µ), first-order molecular hyperpolarizability (β), and their product (µβ). [8][9][10][11][12][13] In this report, we describe the synthesis and the microscopic nonlinear optical properties of two different types of the heterocyclic chromophores. Additional donor of diethylaminostyryl group was tethered to phenothaizine or carbazole that plays as conjugative donor bridge in DEA-PTZ-TCF and DEA-CBZ-TCF (see Figure 1).…”

“…2-Cyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TCF) was commonly employed as a strong electron acceptor to induce strong charge transfer complex. [8][9][10][11][12][13] Energy state diagram to describe the highest occupied molecular orbital (HOMO) energy, the lowest unoccupied molecular orbital (LUMO) energy, and the bandgap were determined by electrochemical analysis and absorption spectroscopic method. The molecular 1 st -order hyperpolarizabilities and the dipole moments of the chromophores were calculated using semiempirical method.…”

Theoretical study on the mechanism of reaction between 3-hydroxy-3-methyl-2-butanone and malononitrile catalyzed by lithium ethoxide

“…2-dicyano methyl ene-4,5,5-trimethyl-2,5-dihydro furan-3-carbonitrile is a strong electron acceptor for nonlinear optics. It is a molecular building block for NLO material [2][3][4][5]. Li et al has reported its single-crystal structure [6].…”