Synthesis and Characterizationof Band-Pass Filter Fabricated with Ion-Beam Sputtered Ta₂O₅ and SiO₂ Coatings for Optical Communication

A novel type of high-performance band pass filter, comprising 12 Fabry-Perot (F-P) resonator cavities and fabricated from Ta₂O₅ and SiO₂ layers synthesized by ion beam sputtering, was developed for optical communication.The influence of the deposition conditions, particularly the layer thickness, on the characteristics of the newly-developed band pass filter was investigated.The results show that the precision control of layer-thickness has a major impact.To be specific, the combination of optical and deposition time control-schemes was capable of precisely controlling the thickness of coupling layers, grown under the optimized conditions.The properties of the newly-designed stable band pass filter included:an insertion-loss of below 0.2 dB in 1479 ~1504 nm range and a transmission-isolation of above 40 dB in 1470~1521 nm and 1578~1651 nm ranges, satisfying well the stringent requirements of optical communication.