Integrated Optoelectronic Devices

We have an expertise in the fabrication and characterization of planar and channel waveguides. These structures are hybrid organic/inorganic materials produced by sol-gel method or polymeric. In particular, we have a setup for the insertion of light in waveguides and the determination of the optical losses. Some of these structures have been used for the fabrication of a hybrid integrated Mach-Zehnder modulator and for an integrated optical filter in the 1.5 um range.
The activities for electro-optical applications are aimed to achievement of a new generation of e-o modulators. e-o modulators are the key elements in fiber-optic telecommunication systems. Forecast for this type of modulator operating at 40 Gbps indicats an increase from 1.6 M$ (2004) to 74.4 M$ (2007) – source: ElectroniCast Corporation. Most of the presently used e-o modulators are based on Lithium Niobate technology. It has reached its intrinsic potentiality and good alternatives are under study

A substantial step ahead is envisaged with the introduction of hybrid e-o materials based on high hyperpolarizable chromophores embedded in polymers or sol-gel based matrix.

However e-o materials are based on second order nonlinear (NL) properties. In order to confer suitable characteristics, non-centrosymmetic geometry presents at molecular level must be preserved when chromophores are inserted into matrices (ordered doping). Nano-manipulation of chromophores can be obtained by electric field orientation of chromophores. The effectiveness of orientation and the evaluation of e-o performances of different systems, most of which synthesized in the framework of international collaborations and projects, are tested measuring their properties of Second Harmonic Generation. Studies about thermal- and photo- stability are performed by means of accelerated aging to orient the choice of better candidate to demonstrators and e-o modulator prototypes.