Photonic and Phononic Band Gap Properties of Lithium Niobate

Abstract

The photonic and phononic band gap properties of lithium niobate are investigated both theoretically and experimentally. The computed photonic band structures are used to discuss the appearance of band gaps and of slow light modes. Actual lithium niobate photonic crystals are presented and a striking phenomenon of enhanced electro-optic coefficient for slow light is emphasized. Phononic crystals fabricated in lithium niobate are then discussed theoretically and experimentally, with an emphasis on phononic band gap properties for surface acoustic waves, i.e. for phonons that are confined close to the surface. Some perspectives for future work are given, including the development of thin layer devices and of phoXonic crystals, artificial crystals that possess simultaneous photonic and phononic band gaps.