Lecture 13 Nanophotonics in plasmonics. EECS Winter 2006 Nanophotonics and Nano-scale Fabrication P.C.Ku

Transcription

1 Lecture 13 Nanophotonics in plasmonics EECS Winter 2006 Nanophotonics and Nano-scale Fabrication P.C.Ku

2 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) 2

3 Outline Today, we will discuss the applications of surface plasmon polaritons in the following areas. Sensing Nanoscale light guiding Nanolithography LED efficiency enhancement 3

4 Surface plasmon for sensing Ref: Prasad, Biophotonics, figures 9.23 and

5 Bio sensing Ref: Prasad, Biophotonics, figure

6 Surface plasmon polariton (SPP) confinement ~100nm ~10nm dielectric metal Most of the energy is confined in the dielectric side. 6

7 Plasmonic planar waveguide L W λ=633 nm Ref: J. R. Krenn and J. C. Weeber, Phil. Trans. R. Soc. Lond. A 362 (2004)

8 Interference Ref: J. R. Krenn and J. C. Weeber, Phil. Trans. R. Soc. Lond. A 362 (2004)

9 Plasmonic nanoparticle waveguide λ=1.55µm. Propagation length = 50µm. Ref: S. Maier et al., Appl. Phys. Lett., 86 (2005)

10 Plasmonic V-groove waveguide Ref: S. Bozhevolnyi et al., Phys. Rev. Lett., 95 (2005)

11 Another example of coupler Ref: W. Nomura et al., Appl. Phys. Lett., 86 (2005)

12 Plasmonic printing Ref: P. G. Kik et al., Proc. Of SPIE, 4810 (2002) 7. 12

13 Ref: P. G. Kik et al., Proc. Of SPIE, 4810 (2002) 7. 13

14 Line/space pattern 2mm Mask pitch 300nm Interference of SPP generates extra fringes Ref: X. Luo and T. Ishihara, Appl. Phys. Lett., 84 (2004)

15 g-line (436 nm) The authors attributed the LER to the mask roughness. Ref: X. Luo and T. Ishihara, Appl. Phys. Lett., 84 (2004)

16 Superlens version I-line (365 nm) Ref:N. Fang et al., Science, 308 (2005)

17 Negative resist ~ 120 nm thick before printing Ref:N. Fang et al., Science, 308 (2005)

18 Spontaneous emission enhancement Corrugated metal can couple SP to radiation. Ref: K. Okamoto et al., Appl. Phys. Lett., 87 (2005)

19 Top-emitting organic LEDs Active layer Alq3 is pumped by a diode 410 nm from the bottom silica sub. Ref: S. Wedge et al., Appl. Phys. Lett., 85 (2004)

20 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)

21 Radiative lifetime shortening in fluorescence process Reduce the risk of photochemical destruction when molecules are in excited states for long time. Enhance quantum yield τ=2 µs w/o Ag: τ=280 µs Ref: D. A. Weitz et al., Opt. Lett., 7 (1982)

22 Directional fluorescence Ref: J. R. Lakowicz et al., J. Phys. D, 36 (2003) R

23 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. 23