Feasibility of Non-Collinear TeO₂ Acoustic-Optic Tunable Filters Used in the Optical Communication

The characteristics and the structure of TeO₂ acoustic-optic tunable filter used in communication are discussed briefly based on the acoustic-optic theory and it is shown that a large optical incident angle and a long interaction length are suitable for the optical add/drop multiplexer based on the TeO₂ acoustic-optic tunable filter. The distribution of acoustic energy flow in the device supports
the large optical incident angle. The long interaction length depends on the change of the device structure to some degree. The measured results of the samples show that the diffraction efficiency reaches at 96% in the tuning range larger than 100nm and the bandwidth is about 2nm. It can be found that there is a good consistency with the basic theoretical mode. The optimized design result shows that the diffraction efficiency can arrive at 100%, and the bandwidth can be less than 0.4nm. Thus, the non-collinear TeO₂ acoustic-optic tunable filter can play an important role in the coming general optical network.