Recent Progresses on the Study of Ultrafast Optical Switching: Materials and Devices

Optical Kerr effect(OKE) and optical bistability(OB) are the important basis for optical switching. Nitrobenzene is an organic OKE material, however, it is not convenient to handle because of its liquid form and its toxicity. Other inorganic crystals such as tantalum potassium niobate and barium titanate are good candidates to replace nitrobenzene, but they have the problem of high price. On the other hand, optical bistability with low input power and slow temporal response in organic polymer waveguide was observed by us recently from push-pull aromatic azobenzene materials1 and optical bistabilities realized in a planar quasi waveguide and a hybrid waveguide made with a polydiacetylene film have also been reported in literature2. Meanwhile, much efforts have continuously been devoted to the search for such better organic materials in thin film form: metallo phthalocyanine is one among them. However, to our knowledge, study of ultrafast optical bistability in organic polymer waveguides has not yet been reported before us. In this paper, we are going to report our recent progresses on the study of the ultrafast optical switch properties of a novel vanadium phthalocyanine, the picosecond response OKE and OB observed from its Langmuir-Blodegett film or from a planar optical waveguide. In addition, the relationship between the chemical structure and the property of ultrafast responses will also be discussed.