Optical and confinement properties of two-dimensional photonic crystals

Abstract

Abstract-We describe experiments on a quasi-two-dimensional (2-D) optical system consisting of a triangular array of air cylinders etched through a laser-like Ga(Al)As waveguiding heterostructure. Such a configuration is shown to yield results very well approximated by the infinite 2-D photonic crystal (PC). We first present a set of measurements of the optical properties (transmission, reflection, and diffraction) of slabs of these photonic crystals, including the case of in-plane Fabry-Perot cavities formed between two such crystals. The measurement method makes use of the guided photoluminescence of embedded quantum wells or InAs quantum dots to generate an internal probe beam. Out-of-plane scattering losses are evaluated by various means. In a second part, in-plane micrometer-sized photonic boxes bounded by circular trenches or by two-dimensional photonic crystal are probed by exciting spontaneous emission inside them. The high quality factors observed in such photon boxes demonstrate the excellent photon confinement attainable in these systems and allow to access the detail of the modal structure. Last, some perspectives for applications are offered.

Nanophotonic waveguides in silicon-on-insulator fabricated with CMOS technology

“…1 shows examples of a single-line-defect waveguide (a so-called W1 waveguide) in a photonic-crystal slab made in SOI. Unlike 3-D photonic crystals, the confinement in the vertical direction is not necessarily perfect, which can result in out-of-plane scattering and can cause leakage of light [8], [9].…”

Physics and applications of photonic nanocrystals

“…Sugimoto et al [13] fabricated and characterised 2D AlGaAs photonic crystal slabs by electron lithography in combination with dry etching. In terms of dimensionality, 2D and 1D counterparts are more feasible to fabrication by existing techniques but they may suffer from diffraction losses along the unconfined spatial directions [14][15][16]. Yet, these losses can be reduced significantly by index guided [17] or again 2D photonic crystal based [18] cladding layers in the perpendicular (out of propagation plane) direction.…”

Etched distributed Bragg reflectors as three-dimensional photonic crystals: Photonic bands and density of states

“…This procedure can be realized at sub-micrometric wavelength scales and allows for the controlled introduction of linear and point defects. A main problem however concerns the control of light propagation in the third (vertical) dimension: even in the case of a waveguide-embedded 2D photonic crystal, radiation losses due to out-of-plane diffraction in the vertical direction cannot be eliminated for photonic modes which lie above the light line [15][16][17].…”