Experimental and theoretical characterization of a lithium niobate photonic crystal

In this letter, we investigate the feasibility of tunable lithium niobate (LiNbO3) photonic crystals. The optical response through a LiNbO3 photonic structure is theoretically determined in order to obtain a photonic band gap with optimal tunability. We show by means of a finite difference time domain simulation that the optimal lattice parameters can provide a Δλ=7nm shift in the photonic band gap for a Δn=0.01 variation of the refractive index with an extinction ratio of −22.5dB. The fabrication process and the optical characterization of these novel photonic crystal structures are also reported. The extinction ratio of the measured photonic band gap is lower than −12dB.