Bulletin of the American Physical Society
2005 APS March Meeting
Monday–Friday, March 21–25, 2005; Los Angeles, CA
Session L35: Nanophotonic Materials, Nonlinear Optics and Spectroscopy II |
Hide Abstracts |
Sponsoring Units: DCP Chair: John Fourkas, Boston College Room: LACC 511B |
Tuesday, March 22, 2005 2:30PM - 3:06PM |
L35.00001: Three-dimensional micro/nano fabrication with photopolymer for the production of functional microdevices Invited Speaker: Three-dimensional (3D) two-photon microfabrication with 100nm resolution is based on pinpoint solidification of two-photon-absorbed polymerization, which is stimulated by focusing a femtosecond pulsed laser beam inside a photopolymer [1]. The 3D scanning of the laser beam permits the fabrication of any 3D microstructures. This technique has been widely applied to create functional micro/nano devices such as photonic crystals [2] and micromechanical components [3, 4]. Currently the development of 3D photonic crystals is one of the most promising applications. On the other hand, we intend to develop micromachines driven by optical radiation pressure to create novel microtools for biotechnology. We demonstrated that a microgear could be rotated around an attached shaft by means of a laser-scanning manipulation technique [3]. Nanotweezers with submicron probes were also developed [4]. The nanotweezers can be driven with femtonewton order force control. Such optically driven micromachines, including micro pumps and manipulators, will be useful for micro total analysis systems and biotechnology. [1] Opt. Lett. \textbf{22}, 132 (1997). [2] Nature \textbf{398}, 51 (1999). [3] J. of Microelectromech. Syst. \textbf{12}, 533 (2003). [4] Appl. Phys. Lett. \textbf{82}, 133 (2003). [Preview Abstract] |
Tuesday, March 22, 2005 3:06PM - 3:18PM |
L35.00002: Laser Direct Writing for Wiring of Nanodevices John Fourkas, Christopher LaFratta, Daniel Lim, Tommaso Baldacchini, Yun Peng, Michael Naughton Making electrical contacts to nanorods or nanowires generally requires the use of electron-beam lithography, which can be a time-consuming and complex process. We demonstrate the use of multiphoton laser direct writing to make electrical contacts to metallic nanorods. The entire process takes a matter of hours and can be accomplished on the bench top. Four-probe conductivity measurements show that the contacts to the nanorods are of high quality. We will also discuss applications of these nanodevices. [Preview Abstract] |
Tuesday, March 22, 2005 3:18PM - 3:54PM |
L35.00003: Two-Photon Absorbing Materials for 3D Microfabrication, Sensing and Imaging Invited Speaker: The design of conjugated organic chromophores with large two-photon cross sections and how these chromophores can be used to develop highly efficient materials for two-photon 3D microfabrication, sensing and imaging applications will be described. Two-photon excitation of materials with focused laser beams allows for free-form patterning of materials in three dimensions with nanoscale ($<$ 200 nm) resolution. We have been developing efficient photoactive precursor materials for two-photon 3D patterning of polymers, in both positive and negative patterning processes. We have also developed a class of photoactive nanocomposites containing metal nanoparticles that allow for direct patterning of continuous metal features using lasers or electron beams. We are utilizing these two-photon materials and fabrication processes to prepare 3D microstructures that are of interest for photonic, microfluidic, and micromechanical applications, as well as others. An overview of our efforts to develop two-photon 3D microfabrication will be presented and the wide range of 3D microstructures that can be fabricated with this method will be highlighted. The coupling of two-photon chromophores to ligand receptors for sensing of metal ions, the assembly of two photon dyes on metal nanoparticles to make ultrabright nanobeacons, and the strong enhancement of two-photon excited fluorescence by coupling of chromophores to clusters of metal nanoparticles will also be discussed. [Preview Abstract] |
Tuesday, March 22, 2005 3:54PM - 4:06PM |
L35.00004: Toward Three-Dimensional MEMS Fabricated by Multiphoton Absorption Polymerization Richard Farrer, Christopher LaFratta, Tommaso Baldacchini, Michael Naughton, John Fourkas The use of multiphoton absorption polymerization (MAP) to produce three-dimensional structures with sub-micrometer resolution has garnered attention recently. While many of these polymeric systems are quite impressive, the functionality of a purely polymeric structure is quite limited. We have developed a method by which metal can be deposited selectively onto an acrylic polymer structure that has been fabricated \textit{via} MAP. Postpolymerization chemical modification of the polymer provides moieties that have the ability to reduce metal ions or bind metal ions and/or metal nanoparticles. Additional electroless enhancement of the metal produces a conductive structure. This method provides a means to produce three-dimensional micro-electro-mechanical systems by way of MAP. [Preview Abstract] |
Tuesday, March 22, 2005 4:06PM - 4:42PM |
L35.00005: Generation and focusing of radially polarized beams Invited Speaker: Light beams with spatially homogeneous state of polarization have been extensively studied in the past. However, if one can spatially arrange the polarization of light beam purposefully and carefully, new effects that can expand the functionality and enhance the capability of the optical system are expected. One such example that has gained increasing interest recently is laser beams with radial polarization symmetry. In this talk, methods of generating and manipulating radially polarized light in free space using radial analyzer and spiral phase element are described. Realization of optical fiber modes with radial and azimuthal polarization symmetry will be presented. Simple methods of manipulating these radially polarized beams have also been developed. Radially polarized beam has very unique focusing properties when it is focused by high numerical aperture objective lens. For example, a radially polarized beam can be focused into a much tighter focus than linearly or circularly polarized light due to an extremely strong longitudinal field component. Meanwhile, this strong longitudinal field component does not contribute to the Poynting vector along the optical axis. The focusing properties of radially polarized beams can be used for three dimensional shaping of the optical focal field. With proper combination of radial polarization and azimuthal polarization, optical focal field with flattop profile can be obtained. Combined with diffractive optical phase element, it is possible to obtain optical focus with maximally homogenized field profile in both longitudinal and transversal directions. Optical bubble with dark hollow center as well as chain-like optical focal field can be generated. Finally, the applications of radially polarized beams in optical tweezers, high resolution optical microscopy and materials characterization will be discussed. [Preview Abstract] |
Tuesday, March 22, 2005 4:42PM - 4:54PM |
L35.00006: Optically Active Sum-Frequency Generation from Solution of Molecules with a Chiral Center Na Ji, Yuen-Ron Shen Optically active sum frequency generation (OA-SFG) is being developed as a novel probe for investigation of molecular chirality. We report here the first attempt of OA–SFG to study chirality of molecules with a chiral center but an intrinsically achiral chromophore in isotropic solution. We used amino acids in 4M NaOH solution as the model systems, and found that similar to circular dicroism (CD), OA-SFG near electronic resonance appears to originate from the extrachromophoric chiral perturbation on the carboxyl chromophore. The difference between CD and OA-SFG, however, is in the details of the perturbations pertinent to the two effects, giving rise to different relative strengths of OA-SFG and CD among different amino acids. A general theoretical formulation for OA-SFG from molecules with chiral centers will be presented. [Preview Abstract] |
Tuesday, March 22, 2005 4:54PM - 5:06PM |
L35.00007: Optical Lattice Microscopy Eric Betzig New classes of two- and three-dimensional optical lattices are described that yield excitation maxima of controllable polarization and periodicity relative to the excitation wavelength, confined to near the diffraction limit in all directions. Methods for their generation are proposed, as are methods for the simultaneous, independent detection of luminescence from numerous maxima across multiple lattice planes when such lattices are applied to dynamic live cell imaging or massively parallel single molecule spectroscopy. Performance metrics are also introduced that favorably compare lattice microscopy to widefield, confocal, and 4pi microscopy in terms of speed, resolution, photobleaching, and molecular sensitivity. Finally, the possible adaptation of lattice microscopy to superresolution methods such as total internal reflection microscopy and stimulated emission depletion microscopy is discussed. [Preview Abstract] |
Tuesday, March 22, 2005 5:06PM - 5:18PM |
L35.00008: Fundamental limitation of the spatial resolution of a perfect nanolens Ivan Larkin, Mark Stockman We have established a fundamental limitation on the ultimate spatial resolution of the perfect lens (thin metal slab) in the near field. This limitation stems from the spatial dispersion of the dielectric response of the Fermi liquid of interacting electrons in the nanolens material. Such dispersion leads to the aberrations of this lens in the wave vector space in the plane of the slab. This principally limits the resolution of this lens making it imperfect on the scale below five nanometers. This effect is different and independent from the known source of the lens imperfection due to the absorption (optical losses) in the metal and temporal dispersion that is related to the absorption by Kramers-Kronig relations. Even if the absorption is reduced or compensated by the optical gain the spatial dispersion will remain and limit the resolution. We reveal the link between this limitations and dispersion of surface plasmons. We discuss possible applications in nanoimaging, nano- photolithography, and nanospectroscopy. [Preview Abstract] |
Tuesday, March 22, 2005 5:18PM - 5:30PM |
L35.00009: Localized Plasmons of Nanometric Holes in Thin Gold Films M. Kall, T. Rindzevicius, Y. Alaverdyan, P. Hanarp, D. Sutherland, A. Dahlin, F. Hook, J. Garcia de Abajo, J. Prikulis We have investigated the optical properties of sub-wavelength (60-200 nm) holes in 20 nm thin Au films using extinction and elastic scattering spectroscopy [1]. The samples are prepared by colloidal lithography on glass and consist of either spatially isolated holes or disordered hole arrays with varying density. We show that single holes exhibit a well-defined optical resonance in the visible to near-infrared spectral region, which we assign to a localized surface plasmon (LSP) excitation. The hole LSP red-shifts with increasing hole size or with increasing refractive index of the surrounding medium, in analogy with LSP's in metal nanoparticles, but exhibit a pronounced blue-shift with decreasing hole density, possibly due an enhanced hole-hole coupling mediated via surface plasmon polaritons. Similar to particle plasmons or flat metal surfaces, the hole LSP can be used for biochemical sensing based on refractive index contrast. New results on single hole sensing [2] and biofunctionalization of holes using lipid vesicles [3] will be discussed. [1] J. Prikulis et al, Nano Letters 4, 1003-1007 (2004); [2] T. Rindzevicius et al., submitted ms.; [3] A. Dahlin et al., submitted ms. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700