Synthesis And Characterization Of Hybrid Nonlinear Optic Materials With Different Isolation Groups

Nonlinear optic materials are the base of modern laser technology, optical communication, photonic computing and optical storage, which are indispensable in the development of photoelectron and photonic technology. In the past decades, inorganic-organic hybrid materials have been widely investigated and quickly developed. They combine the organic chromophores and inorganic network in the molecular level, having the advantages together and achieving the complementary and optimum properties. In this thesis, the basic theories of second nonlinear optics were introduced, and the research progress of second nonlinear optic materials were reviewed, especially in the field of poled polymer and inorganic-organic hybrid materials. In addition, the guidance of molecular engineering and dye-matrix affection on the design of nonlinear optic materials were analyzed.Designed and synthesized two sorts of functionalized azo alkoxysilane dyes with isolation groups (ICTES-FB, ICTES-EH). Structures of products were identified by1H NMR, element analysis and FTIR. The alkoxysilane precursors were used with tetraethoxysilane (TEOS) to prepare hybrid films by sol-gel method. When the concentration of chromophore FB was40mol%, hybrid film F-FB had the best performance with the second harmonic coefficient (d33) of140.5pm/V. Introduction of isolation groups, in particular large rigid fluorobenzene. could decrease the dipolar-dipolar electrostatic interactions efficiently, improving the corporation of dyes and enhancing the nonlinear property of hybrid materials. This provides approach and possibility for preparation of hybrid materials with excellent macroscopic second nonlinearity by isolation group.Synthesized four tetraene bridge-based alkoxysilane dyes (ICTES-PTA, ICTES-PTB. ICTES-PTC and ICTES-PTD) by organic reactions, such as thiolation. The hybrid films were fabricated by these alkoxysilane dyes and triethoxyvinylsilane (VTES). The hybrid film exhibited highest d33value of130.5pm/V when the concentration of chromophore PTB reached10mol%while the film containing PTD had the half-decay temperature of127℃. Studied and analyzed the effection of different attachments and isolate modes on material macroscopic properties, which reveal structure-property principle in NLO hybrid materials.By post-functionallization method, the DA crosslinked polymer hybrid films were prepared by three-branched chromophore TCN and furan-modified alkoxysilane FTEOS. The three-branched chromophores PTCN and TDR1were spin-coated onto sbustrate directly. The d33value of film F-PTCN was75.2pm/V. Macromolecules had good dispersivity among the inorganic glass. With molecular dendritic structure and introduction of isolation groups modified silica networks, polymer hybrid film showed excellent surface topography and the highest d33of93.5pm/V, and the half-decay temperature of the film reached123℃. This polymer hybrid film would be a new choice in the development of second nonlinear optic materials for applications in devices.