RESUMO
This Letter reports the electro-optical (EO) effect of Poly(3-hexylthiophene-2,5-diyl) (P3HT) nanofibers colloid in a polymer micro-fluidic EO cell. P3HT nanofibers are high aspect ratio semiconducting nanostructures, and can be collectively aligned by an external alternating electric field. Optical transmission modulated by the electric field is a manifestation of the electro-optical effect due to high inner crystallinity of P3HT nanofibers. According to our results, the degree of alignment reaches a maximum at 0.6 V/µm of electric field strength, implying a big polarizability value due to geometry and electrical properties of P3HT nanofibers. We believe that one-dimensional crystalline organic nanostructures have a large potential in EO devices due to their significant anisotropy, wide variety of properties, low actuation voltages, and opportunity to be tailored via adjustment of the fabrication process.
RESUMO
Complete birefringence compensation is demonstrated in plasma-enhanced chemical vapor deposition waveguides by 193-nm postexposure. A single relaxation process dominates the decay in stress anisotropy, indicating that compressive stress from the substrate leads to an elastic stress anisotropy at the core.
RESUMO
A null test method for testing aspheric optical surfaces based on geometric considerations of conic sections is presented. The basic principles have been investigated experimentally by designing and building a modified Mach-Zehnder interferometer. By using optical fibers the inconvenience of alignment has partly been overcome. Phase shifting has been implemented and the measurements are performed with the help of a microcomputer. The performance of the interferometer has been investigated by testing an elliptical toroid mirror. Further improvement of the test procedure by Zernike polynomial decomposition is discussed and performed. Finally, an even more compact conic section interferometer is proposed.
