Metamaterial Optics

Physics: Metamaterials have engineered ε and μ from subwavelength structures. Split-ring resonator (SRR, Pendry 1999): LC circuit with inductance L (ring) and capacitance C (gap); resonance ω_m = 1/√LC; effective μ(ω) = 1 − Fω²/(ω²−ω_m²+iΓω) → μ < 0 near ω_m. Thin wire array: ε < 0 below plasma frequency ω_p. Simultaneously ε < 0 and μ < 0 → n = √(εμ) < 0 (Veselago 1968). Pendry perfect lens (2000): n = −1 slab amplifies evanescent waves → sub-diffraction imaging. Transformation optics (Pendry/Leonhardt 2006): Maxwell's equations form-invariant under coordinate transforms → cloaking and perfect lenses.