Impurity modes in the optical stop bands of doped colloidal crystals

Pradhan, Ranjit D.; Tarhan, I. İnanç; Watson, George H.

doi:10.1103/physrevb.54.13721

Cited by 77 publications

(75 citation statements)

References 19 publications

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Section: D Embedded Defects Via Multistep Proceduresmentioning

confidence: 99%

“…Watson and co-workers doped colloidal suspensions with microspheres of different sizes or dielectric constants, and used this mixture to grow CCs with substitutional impurities. [106] Near-IR transmission spectroscopy was used to probe the optical properties of the wet crystals doped with both donor and acceptor impurities. Defect modes as well as a significant widening of the optical stop band were observed (Fig.…”

Section: Colloidal Self-assemblymentioning

confidence: 99%

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

2006

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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...

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Section: D Embedded Defects Via Multistep Proceduresmentioning

confidence: 99%

Section: Colloidal Self-assemblymentioning

confidence: 99%

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

2006

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“…13 In addition, pure silica or pure ZnS particles, or shells of these materials, can be used for dielectric doping of photonic crystals in order to create localized modes inside the bandgap. 14 In this letter, we demonstrate the fabrication of photonic crystals through a controlled drying 15,16 of a suspension of particles with a high-dielectric ZnS core and a low-dielectric SiO 2 shell. We study optical transmission at normal incidence on thin photonic crystals.…”

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confidence: 99%

Photonic crystals of core-shell colloidal particles

Velikov

Moroz

Blaaderen

2002

Applied Physics Letters

146

100

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We report on the fabrication and optical transmission studies of thin three-dimensional (3D) photonic crystals of high-dielectric ZnS-core and low-dielectric SiO 2 -shell colloidal particles.These samples were fabricated using a vertical controlled drying method. The spectral position and width of a stopgap depend on the core-to-shell ratio, in a manner consistent with numerical calculations. Both experiments and calculations show that the relative L-stopgap width in the case of high-index core low-index shell particles can be larger in comparison to the case of homogeneous particles of either material. The core-shell morphology gives additional control over the photonic stopgap characteristics. § Corresponding authors; electronic mails: K.P. Velikov@phys.uu.nl, A.vanBlaaderen@phys.uu.nl

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“…In fact, detailed measurements of photonic bandstructure have only been reported in relatively few cases, and most of these cases are restricted to direct structures with relatively weak particle scattering and some disorder, 151,[239][240][241][242][243][244][245] or to the inverted structures made, for example, by filling the voids in artificial opal with high index material, and then removing the opal, 74,75,125,156,246 or other variants of this scheme. 126,240,247,248 To date the inverted materials have demonstrated the most "photonic" behavior (though not a full gap). Thus measurements in many systems (e.g., direct structures with high index particles) are still desirable in order to test our basic understanding of photonics, and open up new ideas for the future.…”

Section: Measurements Of Photonic Bandstructurementioning

confidence: 99%

“…136,139,[240][241][242][248][249][250] With few exceptions, 251 the measurements have been complicated by the fact that the samples were not usually single crystals. These methods range from studies of the spectrum of embedded fluorescent molecules, to studies of transmission versus wavelength at fixed angle, to angle-dependent studies of reflection or transmission versus wavelength.…”

Section: Measurements Of Photonic Bandstructurementioning

confidence: 99%