16×16 Silicon Optical Switch Based On Thermo-optic Mach-Zehnder Interferometer

According to the forecast of Cisco,the IP traffic will grow at a compound annual growth rate of 23 percent from 2014 to 2019 and the annual IP traffic will surpass the two zettabytes threshold in 2019.The continuous demand for higher data transmission bandwidth requires energy-efficient switching to support the ever-growing intelligent and programmable optical networks.And optical switches are highly demanded for the construction of data centers and high-performance computers optical interconnection networks for increasing the speed of data exchange and reducing power consumption.Silicon-integrated optical switches,together with other silicon photonics devices based on siliconon-insulator(SOI)substrates and complementary metal–oxide–semiconductor(CMOS)-compatible process technologies,are widely regarded as the most promising devices for applications in data communications and telecommunications.They are compact,have a low power consumption and low cost,and are fit for large-scale monolithic integration.Hence,silicon large-port-count integrated optical switch chips have important academic value and extensive applications in optoelectronics.It has become a research hotspot in recent years.This dissertation focuses on the large-port-count integrated optical switch.We give the working principle and key characteristics of silicon optical switch.We have designed and experimentally demonstrated a compact,low loss and low crosstalk 16×16 reconfigurably non-blocking optical switch.The switch chip is based on a Benes structure and consists of 56 2×2 MZIs,with each arm integrated with a waveguide micro-heater.The switch chip is built on the SOI platform using the CMOS-compatible process with a footprint of only 7 mm×3.6 mm.The on-chip insertion loss is 5.2 dB at 1560 nm and the worst crosstalk is better than-30 dB over a 10-nm bandwidth.The switching power for each switch element to change the state is about 22 mW.The total power consumption is 515 mW at the all-cross state and 1428 mW at the all-bar state.The power consumption could be reduced if TO tuning is performed on both arms.The switching time is around 22 ?s.Optical signal transmission experiments using a 40 Gb/s QPSK signal confirms the signal fidelity after passing through the switch chip.At last,we summarize the research work in this dissertation and give our foresight for the silicon large-port-count optical switch chip.