Nanostructured Materials with Nonlinear Optical Properties (NANONLO)
Advances in optical communication technologies have created the need for materials with nonlinear optical (NLO) properties. Ideal materials for photonics applications should combine large nonlinear optical susceptibility coefficients with good optical quality and low optical loss. While ferroelectric crystalline materials are being used in this field, there is currently intensive research effort towards exploring less expensive materials, both inorganic and organic, which can exhibit sufficient and stable NLO properties.
Unlike crystalline materials, glasses may be easily prepared in the form of long fibers and optically homogeneous films by means of simple and inexpensive processes; this offers the opportunity for developing structures with NLO properties in integrated optical devices. However, homogeneous glasses do not exhibit even-order optical response or electro-optical effect of the first order because of their centrosymmetric nature. Nevertheless, second-order NLO properties may be observed in glasses as a result of post-synthesis treatments involving intensive laser irradiation, thermal poling or crystallization of phases with large optical nonlinearity.
Polymers may exhibit very efficient second-order NLO response, but the stability of materials and their related properties need to be improved substantially. Development of organic-inorganic hybrids appears a promising way of research for combining useful attributes of organic and inorganic materials in order to achieve an optimum balance of NLO properties with high mechanical and dimensional stability, low optical loss and good thermal stability.
Thermal poling-induced nonlinear optical response by ion migration in ionic glasses (left) and
dipole reorientation in organic-inorganic hybrid materials (right).
At TPCI we pursue an interdisciplinary research program to develop and evaluate materials with promising NLO properties for photonics applications. Materials belonging to the following classes are being currently considered in this field: