1. Negative Index/Refraction & Fabrication + Application EE235 2 nd presentation May 4 th, 2009 Jun Rho

2. Cloaking & Invisible Man

3. Refraction & Snell’s law Snell’s law Total Internal Reflection

4.           metals, ionic crystals most dielectrics no natural materials negative  materials Refractive Index S k RHM LHM S k RHM Snell’s Law (p = -1 for LHM) n1n1 n2n2 n2n2 n1n1 “Practical Applications” SuperLens HyperLens Cloaking Negative Index Metamaterials

5. Superlens: Principle X. Zhang et al, Vol. 308, pp 435-441, Nature Materials, 2008 Diffraction limit w/o superlens Diffraction limit w superlens

6. Superlens: Experiment N. Fang et al, Vol. 308, pp1534-5376, Science, 2005 Resolution achieved about 60-90nm At wavelength = 365nm

7. Superlens: Fabrication N. Fang et al, Vol. 308, pp1534-5376, Science, 2005 1.Cr deposition on a quartz substrate 2.Focused Ion Beam (FIB) patterning 3.Planarization 4. PMMA spacer layer deposition 5.Ag layer deposition 6.Near field photolithography

8. Images after hyperlens Diffraction limit w/o hyperlens 22 pairs (R1: 400nm, R2: 1940nm) 0.04 |H| 0 0.02 45pairs 10nmAg/10nm Ta2O5(R1:100nm,R2:1000nm) Object: 50nm separation, 20nm opening Wavelength: 405nm Hyperlens: Principle Diffraction limit w/ hyperlens At wavelength = 365nm Theoretically, diffraction limit is overcame. (120m < 150nm) Experimental resolution limit?

9. Hyperlens: Experiment 130nm J. Liu et all, Vol. 315, p 1686, Science, 2007

10. Hyperlens: Fabrication 1. Cr deposition on the quartz surface 2. Focused Ion Beam (FIB) patterning. 3. HF (BOE) wet etching 4. Remove mask layer 5. Multilayer deposition of Ag and Al 2 O 3 by E-beam evaporator. Finally, the last Cr layer deposition is followed

11. Superlens & Hyperlens X. Zhang et al, Vol. 308, pp 435-441, Nature Materials, 2008 Conventional lens Superlens (Near field) Superlens (Far field) Hyperlens

12. Metamaterials: Principle & Fab. RLC Circuit Negative Permeability (µ) Negative Permittivity (ε) Negative Index (LHM) Wire Grid Polarizer k H E k H E S. Zhang, PRL, 2005 S. Zhang, Opt. Exp., 2005 J. Valentine et al, Nature, 2008

13. Cloaking: Fab. & Experiment J. Valentine et al, pp 1-5, Nature, 2008

14. Superlens More applications Hyperlens Overcoming diffraction limit in visible wavelength Application to Bio-Engineering Cloaking Bulk-metamaterials characteristics Manufacturing Issues Future steps

15. Questions?