158 research outputs found
Replication Of Diffractive Optical Elements By Injection Molding
In this paper we describe the replication processes of DOE carried out at the Diffractive Optics Laboratory/UNICAMP for replicating DOE. In particular we present the results obtained in the replication by injection molding of microlens array, diffraction gratings and polarizing elements. The measurements of the geometric dimensions of the DOE masters, the nickel shims and the replicated structures were accomplished by perfilometry, AFM and SEM microscopy. The optical properties of both the DOE masters and their replicas were evaluated by measuring of the diffraction efficiency as a function of the incident wavelength, for orthogonal polarizations.5622PART 2739744Goodman, J.W., (1996) "Introduction to Fourier Optics", Second Edition, , Mac-Graw HillSoares, L.L., Cescato, L., Metallized photoresist graating as polarizing beam-splitters (2001) Applied Optics, 40 (32), pp. 5906-5910Turunen, Wyrowski, (1997) Diffractive Optics for Industrial and Commercial Applications, , Akademie Verlag, BerlimGale, M.T., Replication techniques for diflractive optical elements (1997) Microeletronic Engineering, 34, pp. 321-339Nikolajeff, F., Jacobsson, S., Hard, S., Billman, A., Lundbladh, L., Lindell, C., Replication of continuous-relief diffractive optical elements by conventional compact disc injection-molding techniques (1997) Applied Optics, 36, p. 4655Daly, D., Stevens, R.F., Hutley, M.C., Davies, N., The manufacture of microlenses by melting photoresist (1990) J. Meas. Sci. Techn., 1, pp. 759-766Nussbaum, Ph., Gonté, F., Boillat, C., Herzig, H.P., Low NA fused silica refractive microlenses for Shack-Hartmann wavefront sensor (2000) Diffractive Optics and Micro-optics, pp. 247-249. , Québec, June 18-22Carvalho, E.J., (2003) Desenvolvimento de Processes de Replicação de Elementes Ópticos Difrativos, , Master thesis, IFGW/UNICAM
Nanosieves Fabricated By Interference Lithography And Electroforming
Self-sustaining Nickel membranes with periodic and regular distribution of pores, in the scale of hundred of nanometers, were produced by interference lithography and electroplating. The process consists in the recording of submicrometric 2D periodic photoresist columns, on a metal-coated glass substrate, using the double exposure of an interference fringe pattern. As the photoresist is a good electrical isolator, when the sample is immersed in a Ni electroplating bath, the array of photoresist columns impedes the Nickel deposition in the patterned areas. A nickel film is then growth among the photoresist columns with a thickness up to 80 % of the height of the columns. In order to release the submicrometric membrane from the substrate, a thick hexagonal Nickel sustaining structure is electroformed, using conventional photolithography. The dimensions of the sustaining structure can be adapted in order to fulfill the pressure requirements of the filtration system. The good uniformity of the pore sizes as well as the smooth of the surface make such devices very interesting for separation of particles by size in filtration systems.6037Sard Ghayeni, S.B., Beatson, P.J., Fane, A.J., Schneider, R.P., Bacterial passage through microfiltration membranes in wastewater applications (1999) J. Membr. Sci., 153, pp. 71-82(2002) Life Science CatalogueCalvo, J.I., Hernandez, A., Pradanos, P., Martinez, L., Bowen, W.R., Pore size distribution in microporous membranes, II bulk characterization of track-etched filters by air porometry and mercury prosimetry (1995) Journal of Colloid and Interface Science, 176, pp. 467-478Han, K., Xu, W., Ruiz, A., Ruchhoeft, P., Chellam, S., Fabrication and characterization of polymeric microfiltration membranes using aperture array lithography (2005) J. Membr. Sci., 249, pp. 193-206Kuiper, S., Van Wolferen, H., Van Rijn, C., Nijdam, W., Krijnem, G., Elwenspoek, M., Fabrication of microsieves with sub-micron pore size by laser interference lithography (2001) Journal, of Micromehcanics and Microengineering, 11, pp. 33-37Van Rijn, C.J.M., Veldhuis, G.J., Kuiper, S., Nanosieves with microsystem tecnology for microfiltration applications (1998) Nanotechnology, 9, pp. 343-345Kuiper, S., Boer, M.D., Van Rijn, C., Nijdarh, W., Krijnen, G., Elwenspoek, M., Wet and dry etching techniques for the release of sub-micrometre perforated membranes (2000) Journal of Micromechanics and Microengineering, 10, pp. 171-174Gutierrez-Rivera, L.E., De Carvalho, E.J., Suva, M.A., Cescato, L., Metallic submicrometric sieves fabricated by interferometric litography and electroforming (2005) Journal of Micromechanics and Microengineering, 15, pp. 1932-1937Griffiths, S.K., Nilson, R.H., Hruby, J.M., (1996) Modeling Electrodeposition for LIGA Microdevice Fabrication, , http://www.ca.sandia.gov/liga/process_archives.html, Sandia National Laboratories, Livermore, CaliforniaFrejlich, J., Cescato, L., Mendes, G.F., Analysis of an active stabilization system for an holographic setup (1998) Appl. Opt., 27, pp. 1967-1976Zaidi, H.S., Brueck, S.R.J., Multiple-exposure interferometric lithography (1993) J. Vac. Sci. Technol. B, 11, pp. 658-666Mello, B.A., Costa, I.F., Lima, C.R.A., Cescato, L., Developed profile of holographically exposed photoresist gratings (1995) Applied Optics, 34, pp. 597-603Mack, C.A., Development of positive photoresists (1987) J. Electrochem. Soc., 134, pp. 148-152Spiro, P., (1971) Electroforming: A Comprehensive Survey of Theory, Practice and Commercial Applications2th Edition, , Robert Draper LTDKuiper, S., Van Rijn, C.J., Nijdam, W., Elwenspoek, M.C., Development and applications of very high flux microfiltration membranes (1998) Journal of Membrane Science, 150, pp. 1-8www.mediacy.co
Photonic Crystals And Plasmonic Structures Recorded By Multi-exposure Of Holographic Patterns
Different technologies can be used for fabrication of photonic crystals such as: self-assembly of colloidal particles, ebeam lithography (EB), interference lithography (IL) and focused ion beam (FIB). Among them, the holographic lithography (HL) is the only technique that is able to fabricate both two-dimensional and three-dimensional photonic crystals, as well as plasmonic structures, in large areas. In this paper we demonstrate the use of the multi-exposure of two-beam interference patterns, with rotation of the sample around different axis, for fabrication of large areas 2D and 3 D photonic crystals and plasmonic structures. Using this technique, we achieved aspect ratios of about 4 in 2D photoresist templates recorded in 1 cm 2 glass substrates. In order to generate the 2D photonic band gap layers and plasmonic structures, we combine the use the high aspect ratio photoresist templates with shadow evaporation of appropriated materials, with a further lift-off of the photoresist. The optical properties of the recorded structures, both photonic and plasmonic, were measured to demonstrate the applicability of the technique. © 2009 SPIE.7358Joannopoulos, J.D., Meade, R.D., Winn, J.N., (1995) Photonic Crystals, , Princeton University PressNotomi, M., Shinya, A., Kuramochi, E., Photonic crystals: Towards ultrasmall lightwave circuits (2004) NTT Tech. Rev. 2, pp. 36-47Ebbesen, T.W., Lezec, H.J., Ghaemy, H.F., Thio, T., Wolff, P.A., Extraordinary optical transmission through sub-wavelenght hole arrays (1998) Nature, 391, pp. 667-669Gordon, R., Sinton, D., Kavanagh, K.L., Brolo, A.G., A new generation of sensors based on extraordinary optical transmission (2008) Accounts of Chemical Research, 41, pp. 1049-1057Cabrini, S., Carpentiero, A., Kumar, R., Businaro, L., Candeloro, P., Prasciolu, M., Gosparini, A., Di Fabrizio, E., Focused ion beam lithography for two dimensional array structures for photonic applications (2005) Microelec. Eng. 78-79, pp. 11-15Brueck, S.R.J., Optical and interferometric lithography-nanotechnology enablers (2005) Proc. IEEE 93, pp. 1704-1721Wijnhoven, J.E.G.J., Vos, W.L., Preparation of photonic crystals made of air spheres in titania (1998) Science, 281, pp. 802-804Deubel, M., Freymann, G.V., Wegener, M., Pereira, S., Busch, K., Soukoulis, C.M., Direct laser writing of three-dimensional photonic-crystal templates for telecommunications (2004) Nature Mater., 3, pp. 444-447Campbel, M., Sharp, D.N., Harrison, M.T., Denning, R.G., Turberfield, A.J., Fabrication of photonic crystals for the visible spectrum by holographic lithography (2000) Nature 404, pp. 53-56Miklyaev, Y.V., Meisel, D.C., Blanco, A., Von Freymann, G., Three-dimensional face-centered-cubic photonic crystal templates by laser holography: Fabrication, optical characterization, and band-structure Calculations (2003) Appl. Phys. Lett., 82, pp. 1284-1286Lai, N.D., Liang, W.P., Lin, J.H., Hsu, C.C., Lin, C.H., Fabrication of two- and three-dimensional periodic structures by multi-exposure of two-beam interference technique (2005) Opt. Express 13, pp. 9605-9611Quiñónez, F., Menezes, J.W., Rodriguez-Esquerre, V.F., Hernandez-Figueroa, H., Mansano, R.D., Cescato, L., Band gap of hexagonal 2D photonic crystals with elliptical holes recorded by interference lithography (2006) Opt. Express 14, pp. 4873-4879Yang, X.L., Cai, L.Z., Wang, Y.R., Larger bandgaps of two-dimensional triangular photonic crystals fabricated by holographic lithography can be realized by recording geometry design (2004) Opt. Express 12, pp. 5850-5856Menezes, J.W., Cescato, L., Carvalho, E.J., Braga, E.S., Recording different geometries of 2D hexagonal photonic crystals by choosing the phase between two-beam interference exposures (2006) Opt. Express 14, pp. 8578-8583Frejlich, J., Cescato, L., Mendes, G.F., Analysis of an active stabilization system for holographic setup (1988) Appl. Opt. 27, pp. 1967-1976Nalin, M., Menezes, J.W., Braga, E.S., Siu Li, M., Messaddeq, Y., Ribeiro, S.J.L., Cescato, L., 2D photonic crystals in antimony-based films fabricated by holography (2008) J. of Appl. Phys. 103, pp. 1061011-1061013Astratov, V.N., Culshaw, I.S., Stevenson, R.M., Whittaker, D.M., Skolnick, M.S., Krauss, T.F., De La Rue, R.M., Resonant coupling of near-infrared radiation to photonic band structure waveguides (1999) J. Lightwave Technol. 17, pp. 2050-205
Holographic technique for measurement of the kinetic constant and optical modulation of photosensitive materials
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)We use a holographic technique to measure simultaneously and separately the temporal evolution of the refractive-index and the absorption coefficient modulations induced by light in a photosensitive material. The technique is phase sensitive, allowing separation of the signals from the phase and from the amplitude grating. The refractive-index and the absorption coefficient modulations as well as the kinetic constant of the photoreaction in the positive photoresist SC 1827 were measured at three different wavelengths. The results were compared with independent measurements, performed under homogeneous exposition. The good accord demonstrates the applicability of the technique to study photosensitive materials. (C) 2010 Optical Society of America491834993505Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fotonica para Comunicacoes Opticas (FOTONICOM)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
DEVELOPED PROFILE OF HOLOGRAPHICALLY EXPOSED PHOTORESIST GRATINGS
A simulation of the profile of holographically recorded structures in photoresists is performed. In addition to its simplicity this simulation can he used to take into account the effects that arise from exposure, photosensitization, development, and resolution of positive photoresists. We analyzed the effects of isotropy of wet development, nonlinearity of the photoresist response curve, background light, and standing waves produced by reflection at the film-substrate interface by using this simulation, and the results agree with the experimentally recorded profiles.34459760
Reflecting polarizing beam splitter
We propose and experimentally demonstrate the use of metal-covered lamellar relief gratings as a polarizing beam splitter operating at a single wavelength near Littrow incidence. We report the characteristics of a grating produced by holography and reactive ion etching that was calculated for operation as beam Splitter at lambda = 633 nm (for a He-Ne laser). (C) 1997 Optical Society of America.22420320
Nuclear Breathing Mode in the Relativistic Mean Field Theory
The breathing-mode giant monopole resonance is studied within the framework
of the relativistic mean-field (RMF) theory. Using a broad range of parameter
sets, an analysis of constrained incompressibility and excitation energy of
isoscalar monopole states in finite nuclei is performed. It is shown that the
non-linear scalar self-interaction and the resulting surface properties
influence the breathing-mode considerably. It is observed that dynamical
surface properties respond differently in the RMF theory than in the Skyrme
approach. A comparison is made with the incompressibility derived from the
semi-infinite nuclear matter and with constrained nonrelativistic Skyrme
Hartree-Fock calculaions.Comment: Latex (12 pages) and 3 figures (available upon request) J. Phys. G
(in press
- …