Development of Low Loss Ultra-High Δ ZrO2-SiO2 PLC for Next Generation Compact and High-Density Integrated Devices

For next generation planar lightwave circuit (PLC) devices, high function and high-density integration are required as well as downsizing and cost reduction. To realize these needs, high refractive index difference between a core and a clad (∆) is required. To use PLC for practical applications, silica-based PLC is one of the most attractive candidate. However, degradation of the optical properties and productivity occur when ∆ of the core becomes high. Thus, ∆ of most of the conventional PLC with GeO2-SiO2 core is designed less than 2.5%. In this paper, we report a silica-based ultra-high ∆ PLC with ZrO2-SiO2 core. 5.5%-∆ ZrO2-SiO2 PLC has been realized with low propagation loss and basic characteristics has been confirmed. Potential of chip size reduction of the ZrO2-SiO2 PLC is shown. key words: integrated optics, MMI coupler, optical communication, optical device, planar lightwave circuit