We present our research into the fabrication of fully three-dimensional metallic nanostructures using diffusion-assisted direct laser writing, a technique which employs quencher diffusion to fabricate structures with resolution beyond the diffraction limit. We have made dielectric 3D nanostructures by multiphoton polymerization using a metal-binding organic-inorganic hybrid material, and we covered them with silver using selective electroless plating. We have used this method to make spirals and woodpiles with 600?nm intralayer periodicity. The resulting photonic nanostructures have a smooth metallic surface and exhibit well-defined diffraction spectra, indicating good fabrication quality and internal periodicity. In addition, we have made dielectric woodpile structures decorated with gold nanoparticles. Our results show that diffusion-assisted direct laser writing and selective electroless plating can be combined to form a viable route for the fabrication of 3D dielectric and metallic photonic nanostructures. 1. Introduction Direct fs laser writing is a technique that allows the construction of three-dimensional micro-and nanostructures [1]. It is based on the phenomenon of multiphoton absorption and subsequent polymerization; the beam of an ultrafast laser is tightly focused into the volume of a photosensitive material, initiating multiphoton polymerization within the focused beam voxel. By moving the beam three-dimensionally, arbitrary 3D, high-resolution structures can be written. By simply immersing the sample in an appropriate solvent, the unscanned, unpolymerized area can be removed, allowing the 3D structure to reveal. A variety of applications have been proposed including microfluidics [2], micro-optics [3, 4], scaffolds for biomolecules and cells [5–7], and photonics and metamaterials [8–10]. There has been a lot of research efforts to improve the resolution of DLW technology, which for a long time has been in the range of 100?nm. The method which most successfully and substantially has increased the resolution not only of single lines but also of 3D structures is DLW inspired by stimulated-emission-depletion (STED) fluorescence microscopy [11, 12]. In STED-DLW, two laser beams are used; one is used to generate the radicals, and the second beam to deactivate them. Several schemes have been proposed including single-photon (rather than multiphoton) excitation [13], a one-color scheme [14] and multiphoton two-color scheme [15, 16]. Structures with very high resolution and very small intralayer distances have been fabricated using this approach.
References
[1]
S. Juodkazis, V. Mizeikis, and H. Misawa, “Three-dimensional microfabrication of materials by femtosecond lasers for photonics applications,” Journal of Applied Physics, vol. 106, no. 5, Article ID 051101, 2009.
[2]
L. Amato, Y. Gu, N. Bellini, et al., “Integrated three-dimensional filter separates nanoscale from microscale elements in a microfluidic chip,” Lab on a Chip, vol. 12, no. 6, pp. 1135–1142, 2012.
[3]
M. Malinauskas, A. Zukauskas, K. Belazaras, et al., “Laser fabrication of various polymer micro-optical components,” The European Physical Journal Applied Physics, vol. 58, Article ID 20501, 8 pages, 2012.
[4]
E. Brasselet, M. Malinauskas, A. ?ukauskas, and S. Juodkazis, “Photopolymerized microscopic vortex beam generators: precise delivery of optical orbital angular momentum,” Applied Physics Letters, vol. 97, no. 21, Article ID 211108, 2010.
[5]
T. S. Drakakis, G. Papadakis, K. Sambani et al., “Construction of three-dimensional biomolecule structures employing femtosecond lasers,” Applied Physics Letters, vol. 89, no. 14, Article ID 144108, 2006.
[6]
V. Melissinaki, A. A. Gill, I. Ortega, et al., “Direct laser writing of 3D scaffolds for neural tissue engineering applications,” Biofabrication, vol. 3, Article ID 045005, 2011.
[7]
S. Engelhardt, E. Hoch, and K. Borchers, “Fabrication of 2D protein microstructures and 3D polymer-protein hybrid microstructures by two-photon polymerization,” Biofabrication, vol. 3, Article ID 3025003, 2011.
[8]
V. Mizeikis, S. Juodkazis, R. Tarozaite, J. Juodkazyte, K. Juodkazis, and H. Misawa, “Fabrication and properties of metalo-dielectric photonic crystal structures for infrared spectral region,” Optics Express, vol. 15, no. 13, pp. 8454–8464, 2007.
[9]
A. Radke, T. Gissibl, T. Klotzbücher, P. V. Braun, and H. Giessen, “Three-dimensional bichiral plasmonic crystals fabricated by direct laser writing and electroless silver plating,” Advanced Materials, vol. 23, no. 27, pp. 3018–3021, 2011.
[10]
M. D. Turner, G. E. Schr?der-Turk, and M. Gu, “Fabrication and characterization of three-dimensional biomimetic chiral composites,” Optics Express, vol. 19, no. 10, pp. 10001–10008, 2011.
[11]
S. W. Hell and J. Wichmann, “Breaking the diffraction resolution limit by stimulated emission: stimulated-emission-depletion fluorescence microscopy,” Optics Letters, vol. 19, no. 11, pp. 780–782, 1994.
[12]
T. A. Klar, S. Jakobs, M. Dyba, A. Egner, and S. W. Hell, “Fluorescence microscopy with diffraction resolution barrier broken by stimulated emission,” Proceedings of the National Academy of Sciences of the United States of America, vol. 97, no. 15, pp. 8206–8210, 2000.
[13]
T. F. Scott, B. A. Kowalski, A. C. Sullivan, C. N. Bowman, and R. R. McLeod, “Two-color single-photon photoinitiation and photoinhibition for subdiffraction photolithography,” Science, vol. 324, no. 5929, pp. 913–917, 2009.
[14]
N. Li, R. R. Gattass, E. Gershgoren, H. Hwang, and J. T. Fourkas, “Achieving λ/20 resolution by one-color initiation and deactivation of polymerization,” Science, vol. 324, no. 5929, pp. 910–913, 2009.
[15]
J. Fischer and M. Wegener, “Three-dimensional direct laser writing inspired by stimulated-emission-depletion microscopy,” Optical Materials Express, vol. 1, pp. 614–624, 2011.
[16]
Y. Cao, Z. Gan, and B. Jia, “High-photosensitive resin for super-resolution direct-laser-writing based on photoinhibited polymerization,” Optics Express, vol. 19, pp. 19486–19494, 2011.
[17]
T. J. A. Wolf, J. Fischer, and M. Wegener, “Pump-probe spectroscopy on photoinitiators for stimulated-emission-depletion optical lithography,” Optics Letters, vol. 36, pp. 3188–3190, 2011.
[18]
I. Sakellari, E. Kabouraki, D. Gray, et al., “Diffusion-assisted high resolution direct femtosecond laser writing,” ACS Nano, vol. 6, no. 3, pp. 2302–2311, 2012.
[19]
K. Terzaki, N. Vasilantonakis, A. Gaidukeviciute, et al., “3D conducting nanostructures fabricated using direct laser writing,” Optical Materials Express, vol. 1, pp. 586–597, 2011.
[20]
S. John, “Strong localization of photons in certain disordered dielectric superlattices,” Physical Review Letters, vol. 58, no. 23, pp. 2486–2489, 1987.
[21]
E. Yablonovitch, “Inhibited spontaneous emission in solid-state physics and electronics,” Physical Review Letters, vol. 58, no. 20, pp. 2059–2062, 1987.
[22]
K. M. Ho, C. T. Chan, and C. M. Soukoulis, “Existence of a photonic gap in periodic dielectric structures,” Physical Review Letters, vol. 65, no. 25, pp. 3152–3155, 1990.
[23]
C. M. Soukoulis and M. Wegener, “Past achievements and future challenges in the development of three-dimensional photonic metamaterials,” Nature Photonics, vol. 5, no. 9, pp. 523–530, 2011.
[24]
J. M. Lourtioz, H. Benisty, V. Berger et al., “Photonic crystals: towards nanoscale photonic devices,” Physics Today, vol. 59, no. 8, pp. 54–55, 2006.
[25]
F. A. Denis, P. Hanarp, D. S. Sutherland, and Y. F. Dufrêne, “Nanoscale chemical patterns fabricated by using colloidal lithography and self-assembled monolayers,” Langmuir, vol. 20, no. 21, pp. 9335–9339, 2004.
[26]
C. García-Meca, J. Hurtado, J. Martí, A. Martínez, W. Dickson, and A. V. Zayats, “Low-loss multilayered metamaterial exhibiting a negative index of refraction at visible wavelengths,” Physical Review Letters, vol. 106, no. 6, Article ID 067402, 2011.
[27]
S. Shukla, X. Vidal, E. P. Furlani et al., “Subwavelength direct laser patterning of conductive gold nanostructures by simultaneous photopolymerization and photoreduction,” ACS Nano, vol. 5, no. 3, pp. 1947–1957, 2011.
[28]
G. J. Leggett, “Direct writing of metal nanostructures: lithographic tools for nanoplasmonics research,” ACS Nano, vol. 5, no. 3, pp. 1575–1579, 2011.
[29]
G. O. Mallory and J. B. Hajdu, Electroless Plating: Fundamentals and Applications, chapter 1, American Electroplaters and Surface Finishers Society, Orlando, Fla, USA, 1990.
[30]
S. Hrapovic, Y. Liu, G. Enright, F. Bensebaa, and J. H. T. Luong, “New strategy for preparing thin gold films on modified glass surfaces by electroless deposition,” Langmuir, vol. 19, no. 9, pp. 3958–3965, 2003.
[31]
N. Vasilantonakis, K. Terzaki, I. Sakellari, et al., “Three-dimensional metallic photonic crystals with optical bandgaps,” Advanced Materials, vol. 24, pp. 1101–1105, 2012.
[32]
A. V. Kabashin, P. Evans, S. Pastkovsky et al., “Plasmonic nanorod metamaterials for biosensing,” Nature Materials, vol. 8, no. 11, pp. 867–871, 2009.
[33]
J. K. Gansel, M. Thiel, M. S. Rill et al., “Gold helix photonic metamaterial as broadband circular polarizer,” Science, vol. 325, no. 5947, pp. 1513–1515, 2009.
[34]
S. Turunen, E. K?pyl?, K. Terzaki, et al., “Pico- and femtosecond laser-induced crosslinking of protein microstructures: evaluation of processability and bioactivity,” Biofabrication, vol. 3, Article ID 045002, 2011.
[35]
D. Roundy and J. Joannopoulos, “Photonic crystal structure with square symmetry within each layer and a three-dimensional band gap,” Applied Physics Letters, vol. 82, no. 22, pp. 3835–3837, 2003.
[36]
M. Deubel, Three-dimensional photonic crystals via direct laser writing: fabrication and characterization [Doctoral thesis], Universitat Karlsruhe, 2006.
[37]
M. Deubel, M. Wegener, S. Linden, and G. Von Freymann, “Angle-resolved transmission spectroscopy of three-dimensional photonic crystals fabricated by direct laser writing,” Applied Physics Letters, vol. 87, no. 22, Article ID 221104, pp. 1–3, 2005.