Fabrication And Analysis Of Glass-based Ion Exchange Integrated Optical Splitter

Optical Splitter is one of the key component in the application of optical communication system, optical network terminal (ONT).passive optical network (PON), CATV system and optical local area network (LAN). It can be used as an optical signal splitter/combiner. In this dissertation, we conducted research on the fabrication and analysis of glass-based ion-exchange integrated optical splitters, which have many advantageous over other kind of optical splitter. The glass-based ion-exchange splitter has good performance, such as low loss, low uniformity, wide band, small size, low cost and good reliability.The glass composition for ion-exchange should fulfill these criteria: sufficient refractive index change upon ion-exchange; Formation of optical quality slabs; stability of the silver ion in the glass; chemical durability; refractive index close to that of the optical fiber. Based on the analysis of a large amount of experiments, we developed a special glass material for ion-exchange technology.The buried channel waveguide can be fabricated by field-assisted ion-exchange technology. The buried channel waveguide' s loss is lower by reduce the influence of the glass surface defect or dust. With the optimized field-assisted process, we obtained waveguides with propagation of 0.2dB/cm and very low mismatch coupling loss to SMF.Based on this ion-exchange process, we designed a novel Y-branch splitter. The fundamental idea underlying the new architecture is to use tilted Y-junctions recursively re-oriented in order to maximize the minimum of the curvature radius of the transitions preceding the considered division stage. It is always possible to design devices very compact but with transitions having a much smoother curvature than those of traditional layouts. The more outputs, the more remarkable of this advantageous. We have also designed a MMI 1×8 optical splitter, and the device's performance is good.With the optimized field-assisted process, we designed the novel Y-branch splitter (including 1×4, 1×8, 1×16, 1×32).Device's performance is good. Based on theBroadex Technologies Co.'s testing results, the insertion loss of the 1*8 device is lower than 11.054dB. uniformity is lower than 0.371dB; and the testing results conducted by ourself is insertion loss lower than 10.67dB, uniformity lower than 0.28dB. The device's uniformity is very low, PDL is 0.2dB, and has very low wavelength dependence (means wide band). The performance of the optical splitter has verified the effectiveness of the proposed Y-branch architecture and the successfulness of the field-assisted ion-exchange glass waveguide technique.