Hmh Chong

Tapered Photonic Crystal Microcavities Embedded in Photonic Wire Waveguides With Large Resonance Quality-Factor and High Transmission

We present the design, fabrication, and characterization of a microcavity that exhibits simultaneously high transmission and large resonance quality-factor (Q-factor). This microcavity is formed by a single-row photonic crystal (PhC) embedded in a 500-nm-wide photonic wire waveguide - and is based on silicon-on-insulator. A normalized transmission of 85%, together with a Q-factor of 18 500, have been achieved experimentally through the use of carefully designed tapering on both sides of each of the hole-type PhC mirrors that form the microcavity. We have also demonstrated reasonably accurate control of the cavity resonance frequency. Simulation of the device using a three-dimensional finite-difference time-domain approach shows good agreement with the experimental results.

Studies of the photonic and optical-frequency phonon properties of arrays of selectively grown GaN micropyramids

An array of GaN micropyramids containing a near-surface InxGa1−xN∕GaN single quantum well has been fabricated using selective area epitaxial overgrowth above a patterned silica mask. The pyramid array has been studied by means of angle-resolved reflection measurements using s- and p-polarized incident light in the near- and mid-infrared optical ranges. We have found that the periodic array of flat-topped pyramids shows marked resonances in the near-infrared optical range due to resonant Bloch modes within the extraction cone and that the angular dispersion of these modes exhibits strong photonic crystal characteristics. The experimental results are in good agreement with the photonic band structure calculated using a scattering matrix formalism. The mid-infrared optical anisotropy properties of the micropyramids were investigated to probe the infrared active phonons of the pyramid array. The A1(LO) phonon of the InxGa1−xN∕GaN single quantum well was identified and the InN mole fraction was estimated from ...

Arrays of selectively grown GaN micro-pyramids: photonic and optical-frequency phonon properties

An array of GaN micro-pyramids containing a near-surface InxGa1-xN/GaN single quantum well has been fabricated using selective area epitaxial overgrowth above a patterned silica mask. The pyramid array has been studied by means of angle-resolved reflection measurements in the near- and mid- infrared optical ranges. We have found that the periodic array of flat-topped pyramids shows marked resonances in the near-infrared optical range due to resonant Bloch modes within the extraction cone and that the angular dispersion of these modes exhibits strong photonic crystal characteristics. The experimental results are in good agreement with the photonic band structure calculated using a scattering matrix formalism. The mid-infrared optical anisotropy properties of the micro-pyramids were investigated to probe the infrared active phonons of the pyramid array. The A1(LO) phonon of the InxGa1-xN/GaN single quantum well was identified and the InN mole fraction was estimated from the mode behaviour.

Elements of Nanophotonics: Photonic Crystals, Photonic Wires, Metamaterials and More

Photonic crystal and photonic wire structures are being produced using a variety of techniques and form a challenging area of research activity. Metamaterials for the optical frequency range are extending what is physically possible and helping to push the boundaries of nanophotonics.

Nanophotonic structures: from photonic crystals to metamaterials

We present a summary of our work concerned with nanophotonic structures-covering fabrication and measurement of 3-D (100) oriented photonic crystals; 2-D coupled-cavity resonators waveguides with enhanced transmission resulting from adjusted cavity matching; 1-D photonic wire waveguides based on silicon-on-insulator, with tapered Bragg gratings-and metamaterials based on arrays of split-ring resonators with polarisation dependent resonances in the visible range.

2D photonic crystal four-port directional coupler

We have fabricated and measured a four-port coupled channel-guide device using W1 channel-waveguides oriented along-/spl Gamma/K directions in a two-dimensional (2D) hole-based planar photonic-crystal fabricated in silicon-on-insulator (SOI) material, with operation at wavelengths around 1550 nm.

Enhanced transmission of photonic crystal coupled-resonator waveguide structure via mode matching

A mode matching method is proposed to improve the coupling efficiency between a photonic crystal coupled-resonator waveguide and a ridge waveguide. It has been demonstrated that the coupling efficiency can be improved by as much as a factor of three

Photonic crystal and photonic wire technology, materials and devices

Light channeling and other structures that exploit strong optical confinement are an essential requirement for the realisation of high-density photonic integrated circuits. Strong confinement and controlled feedback are also important for efficient and compact sources for light with various levels of coherence and directionality. The presentation will survey work on various planar photonic crystal and wire device structures realised both in material systems providing strong vertical confinement (e.g. S-o-I) and in systems with weak vertical confinement such as typical epitaxial III-V semiconductor heterostructures. Work towards the combination of a number of elements into a single photonic IC will be highlighted, as will structures which combine photonic crystal and photonic wire features. Planar microcavities for frequency selection will be featured, in particular. We shall also resurvey briefly the technology aspects of fabrication, including electron-beam lithography (EBL), reactive ion etching (RIE), focused ion-beam etching (FIBS) and excimer laser lithography. Finally we shall consider techniques for the growth of self-organised photonic crystals with greater perfection and better controlled orientation.