Silica-based waveguide devices for photonic networks

Silica-based waveguide devices as represented by planar lightwave circuits (PLCs) are key devices for constructing photonic networks with huge data transmission capacity and flexibility. As a result of recent progress on optical communication networks, dynamically controlled silica-based optical devices have become both significant and practical. The thermo-optic (TO) effect is employed to control optical signals. The devices that have been developed include TO switches, variable optical attenuators (VOAs), and devices in which they are integrated. The silica-based waveguide phase shifters that employ the TO effect in these devices are compact, highly reliable, and suitable for large-scale integration. This paper reviews the large scale matrix switches including an 8 × 8 TO switch and a 32 × 32 TO switch. And a 40-ch VOA integrated AWG multiplexer with tap couplers, micromirrors, and monitor photodiodes is also demonstrated.