Pustaka Ilmiah Universitas Padjadjaran

Abstrak

The Effects of Substitution on the Optical Properties of poly(p-phenylenevinylene) Derivatives

We have studied the optical linear, optical nonlinear and waveguide properties of thin films of newly synthesized poly(phenylenevinylene) (PPV) derivatives: MEH-PPV, M3EH-PPV and copolymer MEH-M3EH-PPV by means of reflectrometry, prism coupling, third harmonic generation spectroscopy and waveguide propagation loss. Anisotropic refractive index measurements by means of waveguide prism coupling and reflectometry were used to analyse the polymer chain orientation in the films. We observed that the absorption coefficient, refractive index, birefringence and third order susceptibility and waveguide loss coefficient are increased in going from MEH-PPV, MEH-M3EHPPV and finally to M3EH-PPV, which indicates that the thin film of M3EH-PPV have the most polymer chain segments oriented parallel to the film plane. For all-optical switching applications, the thin film of MEH-PPV is the most appropriate candidate, since it exhibit a good combination of large value of cubic nonlinearity and small waveguide propagation loss coefficient.