Figure 1: The multifunction nonlinear photonic crystals.
From: On-chip steering of entangled photons in nonlinear photonic crystals
(a) In the single-focusing experiment, the engineered nonlinear photonic crystal serves as the entangled photon source and lens. (b) In the dual-focusing experiment, the engineered nonlinear photonic crystal serves as the entangled photon source, lens and beam splitter (BS).
