Lecture 13 – Nanophotonics in plasmonics EECS 598-002 Winter 2006 Nanophotonics and Nano-scale Fabrication P.C.Ku Schedule for the rest of the semester Introduction to light-matter interaction (1/26): How to determine ε(r)? The relationship to basic excitations. Basic excitations and measurement of ε(r). (1/31) Structure dependence of ε(r) overview (2/2) Surface effects (2/7): Surface EM wave Surface polaritons Size dependence Case studies (2/9 – 2/16): Quantum wells, wires, and dots Nanophotonics in microscopy Nanophotonics in plasmonics Dispersion engineering (2/21 – 3/7): Material dispersion Waveguide dispersion (photonic crystals) EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 2 Outline Today, we will discuss the applications of surface plasmon polaritons in the following areas. Sensing Nanoscale light guiding Nanolithography LED efficiency enhancement EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 3 Surface plasmon for sensing Ref: Prasad, Biophotonics, figures 9.23 and 9.24. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 4 Bio sensing Ref: Prasad, Biophotonics, figure 9.25. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 5 Surface plasmon polariton (SPP) confinement dielectric ~100nm ~10nm metal Most of the energy is confined in the dielectric side. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 6 Plasmonic planar waveguide L W λ=633 nm Ref: J. R. Krenn and J. C. Weeber, Phil. Trans. R. Soc. Lond. A 362 (2004) 739. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 7 Interference Ref: J. R. Krenn and J. C. Weeber, Phil. Trans. R. Soc. Lond. A 362 (2004) 739. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 8 Plasmonic nanoparticle waveguide λ=1.55µm. Propagation length = 50µm. Ref: S. Maier et al., Appl. Phys. Lett., 86 (2005) 071103. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 9 Plasmonic V-groove waveguide Ref: S. Bozhevolnyi et al., Phys. Rev. Lett., 95 (2005) 046802. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 10 Another example of coupler Ref: W. Nomura et al., Appl. Phys. Lett., 86 (2005) 181108. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 11 Plasmonic printing Ref: P. G. Kik et al., Proc. Of SPIE, 4810 (2002) 7. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 12 Ref: P. G. Kik et al., Proc. Of SPIE, 4810 (2002) 7. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 13 Line/space pattern Mask pitch 300nm 2mm Interference of SPP generates extra fringes Ref: X. Luo and T. Ishihara, Appl. Phys. Lett., 84 (2004) 4780. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 14 g-line (436 nm) The authors attributed the LER to the mask roughness. Ref: X. Luo and T. Ishihara, Appl. Phys. Lett., 84 (2004) 4780. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 15 Superlens version I-line (365 nm) Ref:N. Fang et al., Science, 308 (2005) 534. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 16 Negative resist ~ 120 nm thick before printing Ref:N. Fang et al., Science, 308 (2005) 534. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 17 Spontaneous emission enhancement Corrugated metal can couple SP to radiation. Ref: K. Okamoto et al., Appl. Phys. Lett., 87 (2005) 071102. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 18 Top-emitting organic LEDs Active layer Alq3 is pumped by a diode laser @ 410 nm from the bottom silica sub. Ref: S. Wedge et al., Appl. Phys. Lett., 85 (2004) 182. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 19 MDPC = metallic-dielectric photonic crystal L/S= 150/150 nm Active layer MEH-PPV is electrically pumped. Ref: C. Liu et al., Appl. Phys. Lett., 86 (2005) 143501. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 20 Radiative lifetime shortening in fluorescence process Reduce the risk of photochemical destruction when molecules are in excited states for long time. Enhance quantum yield w/o Ag: τ=280 µs τ=2 µs Ref: D. A. Weitz et al., Opt. Lett., 7 (1982) 89. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 21 Directional fluorescence Ref: J. R. Lakowicz et al., J. Phys. D, 36 (2003) R240. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 22 Recommended Readings Plasmonic biosensing P. N. Prasad, Biophotonics Plasmonic waveguide E. Ozbay, Science, 311 (2006) 189. Plasmonic printing P. G. Kik et al., Proc. Of SPIE, 4810 (2002) 7. EECS 598-002 Nanophotonics and Nanoscale Fabrication by P.C.Ku 23.