eprintid: 17178 rev_number: 20 userid: 1419 dir: disk0/00/01/71/78 datestamp: 2013-02-21 22:51:27 lastmod: 2019-06-08 14:55:08 status_changed: 2013-02-21 22:51:27 type: article metadata_visibility: show item_issues_count: 0 eprint_status: archive creators_name: Asher, SA creators_name: Weissman, JM creators_name: Tikhonov, A creators_name: Coalson, RD creators_name: Kesavamoorthy, R creators_email: asher@pitt.edu creators_email: creators_email: creators_email: creators_email: creators_id: ASHER creators_id: creators_id: creators_id: creators_id: title: Diffraction in crystalline colloidal-array photonic crystals ispublished: pub divisions: sch_as_chemistry full_text_status: public abstract: We characterized the diffraction and crystal structure of a crystalline colloidal array (CCA) photonic crystal composed of [Formula presented] diameter polystyrene spheres which have a nearest neighbor spacing of [Formula presented]. This CCA diffracts light in first order at [Formula presented] and shows strong diffraction in the visible spectral region from higher order planes. We quantitatively examined the relative diffraction intensities of the putative fcc (111), (200), (220), and (311) planes. Comparing these intensities to those calculated theoretically we find that the crystal structure is fcc with significant stacking faults. Essentially, no light transmits at the Bragg angle for the fcc (111) planes even through thin [Formula presented] thick CCA. However, much of this light is diffusely scattered about the Bragg angle due to crystal imperfections. Significant transmission occurs from thin samples oriented at the Bragg condition for the fcc (200), (220), and (311) planes. We also observe moderately intense two-dimensional diffraction from the first few layers at the crystal surfaces. We also examined the sample thickness dependence of diffraction from CCA photonic crystals prepared from [Formula presented] polystyrene spheres whose fcc (111) planes diffract in the visible spectral region. These experimental observations, aided by calculations based upon a simple but flexible model of light scattering from an arbitrary collection of colloidal spheres, make clear that fabrication of three-dimensional photonic band gap crystals will be challenged by crystal imperfections. © 2004 The American Physical Society. date: 2004-01-01 date_type: published publication: Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics volume: 69 number: 6 pagerange: 14 - ? refereed: TRUE issn: 1063-651X id_number: 10.1103/PhysRevE.69.066619 pmid: 15244776 mesh_headings: Biophysics--methods mesh_headings: Colloids--chemistry mesh_headings: Crystallization mesh_headings: Crystallography--methods mesh_headings: Lasers mesh_headings: Models, Statistical mesh_headings: Photons mesh_headings: Polystyrenes--chemistry chemical_names: Colloids chemical_names: Polystyrenes citation: Asher, SA and Weissman, JM and Tikhonov, A and Coalson, RD and Kesavamoorthy, R (2004) Diffraction in crystalline colloidal-array photonic crystals. Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, 69 (6). 14 - ?. ISSN 1063-651X document_url: http://d-scholarship-dev.library.pitt.edu/17178/1/licence.txt