Near-field spectroscopy of low-loss waveguide integrated microcavities

International audienceA scanning near-field spectroscopy method is used to observe loss reduction and Q-factor enhancement due to transverse-mode profile matching within photonic-crystal microcavities. Near-field measurements performed directly on cavity modes are compared with three-dimensional calculations and quantitative agreement is observed. (c) 2006 American Institute of Physics

The multiple faces of self-assembled lipidic systems

Lipids, the building blocks of cells, common to every living organisms, have the propensity to self-assemble into well-defined structures over short and long-range spatial scales. The driving forces have their roots mainly in the hydrophobic effect and electrostatic interactions. Membranes in lamellar phase are ubiquitous in cellular compartments and can phase-separate upon mixing lipids in different liquid-crystalline states. Hexagonal phases and especially cubic phases can be synthesized and observed in vivo as well. Membrane often closes up into a vesicle whose shape is determined by the interplay of curvature, area difference elasticity and line tension energies, and can adopt the form of a sphere, a tube, a prolate, a starfish and many more. Complexes made of lipids and polyelectrolytes or inorganic materials exhibit a rich diversity of structural morphologies due to additional interactions which become increasingly hard to track without the aid of suitable computer models. From the plasma membrane of archaebacteria to gene delivery, self-assembled lipidic systems have left their mark in cell biology and nanobiotechnology; however, the underlying physics is yet to be fully unraveled

Erbium-Doped Photonic Crystal Microcavity for Light Extraction Enhancement at 300 K

International audienc

Subwavelength imaging of field confinement in a waveguide-integrated photonic crystal cavity

International audienc

Experimental demonstration of Bloch mode parity change in photonic crystal waveguide

International audienc

Bloch mode coupling investigation in silicon-on-insulator W1 photonic crystal waveguide

International audienc

Ultracompact silicon-on-insulator ridge-waveguide mirrors with high reflectance

International audienceMicrocavities offering small modal volumes V_0.6 __/n_3 and consisting of two identical tapered Bragg mirrors etched into a monomode silicon-on-insulator ridge waveguide are studied for operation at telecommunications wavelengths. The authors have measured a Q factor of 8900, for a loaded cavity with a peak transmission at resonance in excess of 60%. The measured Q value quantitatively agrees with the calculation results and is 20 times larger than those previously reported for similar geometries without tapers

Silicon-on-insulator based quasi 3D photonic crystal structures

International audienc

Near-field control and switching of an optical signal

Bringing a nanoscale tip into the evanescent near field of a nanocavity shifts the resonance and allows switching of photon transmission