PhoXonic Crystals in Lithium Niobate

The objective of this project funded by the french National Research Agency (ANR) is to demonstrate the remarkable potential lying behind the integration of periodic nano- structures into active integrated photonic devices made of lithium niobate, an appealing material owing to its particularly high acousto-optic, electro-optic, piezoelectric, and optically nonlinear properties.

This work will address the combination of the effects induced by the periodic nano-structuration of the crystal with two of its intrinsic properties: the electro-optic and the acousto-optic effects.

First, highly efficient electro-optical intensity modulators based on lithium niobate photonic crystals will be designed, fabricated and tested. The idea here is to take advantage of slow-light phenomena linked to the periodicity of the nano-structure to obtain ultra-compact (a few tens of micron long), large bandwidth (over 10 GHz) modulators with low driving voltages (below 2V).

The second part of the planned activities, more fundamental and exploratory, will be devoted to the study of acousto-optical interactions in periodic nano-structured crystals. Conventional modulation configurations, where the electromagnetic wave propagation properties are affected by an elastic wave through the elasto-optic effect, will first be looked into. The objective here is to demonstrate an acousto-optical counterpart of the intensity electro-optical modulator. Acousto-optical modulators based on a collinear configuration will also be studied in order to demonstrate slow light or slow sound based polarization couplers.

Eventually, periodic nanostructures exhibiting both photonic and phononic band gaps will be designed and investigated. The main added-value of these “deaf and blind” materials, that we call “phoxonic crystals”, comes from the simultaneous confinement and slowing down of light and sound in sub micron size structures. This opens the path to a novel generation of highly efficient acousto-optical devices.

This research project 'phoXcry' is funded by the french National Research Agency (ANR) for 3 years (2009-2012) under the programme P3N

FEMTO-ST Institute Coordinator

IEMN

LPMC - Université Nice

Thales Research and Technology