2. + - Energy (eV) ‏ Extinction (a.u.) ‏ D=130nm d 1 =200nm d 2 =150nm Subradianceenhance thesharpening ofthe linewidth! Max: 91 Max: 23Max: 112 Max:18Max: 120 J. Aizpurua et al PRL 90, 057401 (2003) Fabricated in IMEC F. Hao et al PRB 76, 245417 (2007)

3. Extinction (a.u.)‏ Plasmon Energy (eV)‏ d 1 =200nm d 2 =180nm H=50nm D=100nm D=130nm D=150nm D=160nm D=170nm

4. Wavelength (nm)‏ Extinction (a.u.)‏ d 1 =200nm d 2 =150nm D=90nm H=50nm d 1 =200nm d 2 =150nm D=120nm H=50nm d 1 =200nm d 2 =180nm D=150nm H=50nm d 1 =200nm d 2 =180nm D=150nm H=25nm d 1 =600nm d 2 =540nm D=450nm H=75nm

5. Max: 110 Max: 11 k E θ Max: 102 Max: 41 Max: 36 θ =90° Max: 119 Max: 38 Max: 24 Max: 21 θ=45° Wavelength (nm)‏ Extinction (a.u.)‏ θ=0° Wavelength (nm)‏ A common substrate for both SERS and SEIRA !

6. Wavelength (nm)‏ Extinction (a.u.)‏ λ=1398 nm λ=2666 nm λ=1398 nm λ=2726 nm λ=2801 nm λ=1469 nm Wavelength (nm)‏ k E

7. + - Plasmon Energy (eV)‏ Extinction (a.u.)‏ k E k E

8. + - Wavelength (nm)‏ |α| (a.u.)‏ λ=1398nmλ=1583nm λ=2726nm |α| from FDTD |α| fitted by Fano model Individual resonances in Fano model Fano model:

9. k 1, γ 1 k 2, γ 2 Γ F1F1 F2F2 C.L. Garrido Alzar et al Am. J. Phys. 70 (1), 37-41 (2002) Bright mode Dark mode

10. λ=2726nm λ=768nm λ=1417nm λ=937nm + - θ=90° θ=45° θ=0° Wavelength (nm)‏ Extinction (a.u.)‏ k E θ θ=15° θ=30° θ=60°

11. + - θ=90° θ=45° θ=0° k E θ ` θ=15° θ=30° θ=60°