Introducing Defects in 3D Photonic Crystals: State of the Art

Abstract

Public Reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comment regarding this burden estimates or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188,) Washington, DC 20503. AGENCY USE ONLY ( Leave Blank)2. REPORT DATE Advanced Materials, 18, 2665-2678 (2006). 3D photonic crystals (PhCs) and photonic bandgap (PBG) materials have attracted considerable scientific and technological interest. In order to provide functionality to PhCs, the introduction of controlled defects is necessary; the importance of defects in PhCs is comparable to that of dopants in semiconductors. Over the past few years, significant advances have been achieved through a diverse set of fabrication techniques. While for some routes to 3D PhCs, such as conventional lithography, the incorporation of defects is relatively straightforward; other methods, for example, selfassembly of colloidal crystals (CCs) or holography, require new external methods for defect incorporation. In this review, we will cover the state of the art in the design and fabrication of defects within 3D PhCs. The figure displays a fluorescence laser scanning confocal microscopy image of a y-splitter defect formed through two-photon polymerization within a CC. SUBJECT TERMS 15. NUMBER OF PAGES 1416. PRICE CODE SECURITY CLASSIFICATION OR REPORT UNCLASSIFIED SECURITY CLASSIFICATION ON THIS PAGE UNCLASSIFIED SECURITY CLASSIFICATION OF ABSTRACT UNCLASSIFIED LIMITATION OF ABSTRACT UL IntroductionPhotonic crystals (PhCs) are materials that possess spatial periodicity in their dielectric constant on the order of the wavelength (k) of light. These materials can strongly modulate light [1] and, with sufficient dielectric contrast and an appropriate geometry, may exhibit a photonic bandgap (PBG). This concept was first proposed in 1975 by Bykov [2] but remained relatively unknown until the seminal work of Yablonovitch [3] and John. [4] In a rough analogy to semiconductors, which possess an electronic bandgap, a PBG material prohibits the existence of photons with energies in the PBG. PhCs are naturally classified by the dimensionality of their periodicity, and in order to rigorously prevent the propagation of PBG frequencies in all directions, a 3D PhC with an omnidirectional, or complete PBG (cPBG) is required. cPBG materials have been fabricated and well characterized for operation at microwave and radio frequencies, however, operation in the visible and IR requires the characteristic length scales of these structures to be scaled down by several orders of magnitude...

Optical surface resonance may render photonic crystals ineffective

“…This surface resonance is demonstrated for two different three-dimensional (3D) photonic crystals and is expected to occur in a large number of photonic crystal systems including those made by holography, phase mask lithography, two-photon polymerization in addition to the systems presented here. 9 Such resonances prohibit coupling light to optically active features including resonant cavities or embedded defects 10 within the structure since all photons are reflected at the surface. Likewise, slow photon propagation, negative refraction or super-prism effects would also be negatively affected since they require coupling of photons to specific optical modes.…”

Fluorescent polystyrene photonic crystals self-assembled with water-soluble conjugated polyrotaxanes

“…6,7 Among them, self-assembled PhCs have been studied in detail due to their low cost of fabrication and ease of preparation, with artificial opals 1,2,8,9 being especially popular. Synthetic opals provide versatile systems that can be infiltrated by vapour phases, 10 or solutions, 11 thereby enabling the investigation of a variety of photonic effects and especially the fine-tuning of the optical properties. 12 These include the modification of the emission spectra and of the radiative rates, 13,14 optical switching, 15 and Fano resonances.…”

Thermal transport in 2- and 3-dimensional periodic “holey” nanostructures

“…Three-dimensional periodic dielectric structures have distinctive optical properties [46][47][48] and are of great interest in designing new functionalities in optoelectronics. They may also possess promising thermoelectric properties.…”