The results of a detailed investigation of light transmission behavior of a centric marine diatom species <i>Coscinodiscus
wailesii</i> are reported. We measured 3-dimentional intensity distributions of both broadband and monochromatic light
transmitted through individual valves of the diatom in air and water. Cross-sectional intensity profiles of transmitted
light indicates valves of <i>C. wailesii</i> can concentrate light into certain regions. At a distance from the valve shorter than its
diameter, light intensities close to the optical axis are relatively higher than those in the surrounds; at a longer distance,
transmitted light intensities display ring-shaped profiles. The distance showing this light concentration characteristic
becomes shorter as the wavelength of incoming light goes up. These results may offer insight into the understanding of
biological functions of diatom frustules' intricate structures and inspire new optical biomimetic applications.
In this presentation, a simple patchwork to the classical mode matching method (MMM) is proposed to analyze rib ARROWs. MMM gives the modal effective index and the lateral part of modal power loss, and the total modal loss is obtained by including the vertical part which is estimated by a simple yet physical method described here. The simplified MMM (SMMM) is also presented to analyze the effect of TE-TM couplings. Simulation results of selected rib ARROW structures are discussed and compared with those obtained by the Effective Index Method (EIM).
An ARROW-B (antiresonant reflecting optical waveguide, type B) surface plasmon resonance (SPR) sensor operating in aqueous environment is proposed. The characteristics, design, and optimization of the Au-coated ARROW-B SPR sensor are discussed. The operating range of the sensor can be shifted by adding a dielectric overlay. The detectable changes of the refractive index down to the order of 10<SUP>-5</SUP> can be achieved. The design of an ARROW SPR sensor on Si substrates for detecting hydrogen molecules with palladium as the metal film will also be discussed.