Multi-Band Operated and Low Power Consumption TO VOA on Silica Platform

Silica based planar lightwave circuit (PLC) technology is wide commercialized for passive device but suffers from high power consumption. In this letter, a multi-band operated thermo-optic (TO) variable optical attenuator (VOA) with a low power consumption is demonstrated experimentally on silica-based PLC platform. To achieve multi-band and low loss property, Bezier multimode interferometer is utilized for the Mach–Zehnder interferometer based VOA. With folded modulation arms introducing, the power consumption for $\pi $ shift is reduced to 134/156 mW at 1310/1550 nm. The insertion losses/excess losses in O band and C+L band are lower than 4.4/0.9 dB and 4.7/0.7 dB, respectively. The attenuations are larger than 10.1 dB in O band and 16.0 dB in C+L band. The maximum attenuations are 14.8/28.2 dB at 1320.21/1594.40 nm. At 1310/1550 nm, the rise (10%–90%) and fall time (90%–10%) of the optical signal in VOA are 0.94/0.56 ms and 1.13/1.32 ms, respectively. The proposed structure is potential for optical switch, tunable filter, and other TO devices with broadband and power efficient property.