Second Harmonic Generation (SHG) — Phase Matching in Nonlinear Crystals

Crystal length L: 1.0 Phase mismatch Δk: 0.00 χ² coupling: 0.5 Toggle Wave Anim Reset

Second harmonic generation: fundamental beam at ω drives second harmonic at 2ω in a χ² nonlinear crystal. Phase matching (Δk=k₂ω−2kω=0) is critical: when matched, SHG grows as sin²(χ²L); when mismatched, it oscillates with coherence length L_c=π/|Δk|. Efficiency ~sinc²(ΔkL/2).