We report our recent progress on high-throughput 16×16 silicon non-blocking optical switches based on Mach- Zehnder interferometers (MZIs) and dual-ring assisted MZIs (DR-MZIs). TiN microheaters and p-i-n diodes are both integrated in each switch element for thermo-optic phase error correction and GHz-speed electro-optic switching, respectively. The MZI switch exhibits a broad optical bandwidth and low crosstalk. The DR-MZI switch exhibits low electrical switching power but with a narrower optical bandwidth. The two types of switches are designed to have a chip size of 12.1 mm × 4.6 mm mainly restricted by the chip package requirement. The DR-MZI chip can potentially have a smaller footprint due to its much more compact switch element, suitable for high-density on-chip optical data exchange.
We report our recent progress on reconfigurable optical true time delay lines (RTTDL) and optical switches. The
RTTDL is composed of 8 stages of MZIs connected by 7 waveguide pairs with an incremental length difference.
Variable optical attenuators are inserted in the delay waveguides to suppress crosstalk caused by the residual signals
from noise paths. Transmission of a 25 Gbps PRBS signal confirms the signal fidelity after a maximum of 1.27 ns
delay. The optical switch is based on a Benes architecture with Mach-Zehnder interferometers (MZI) as the
switching elements. Both p-i-n diodes and silicon resistive micro-heaters are integrated in the MZI arms for
electrical tuning and phase correction, respectively. The measured on-chip insertion loss of the 4×4 switch is < 8 dB.
Transmission of a 50 Gb/s quadrature phase shift keying (QPSK) optical signal verifies its switching functionality.
We present our recent work on integrated silicon photonic devices for optical filter and delay applications. A microdisk
resonator integrated with interleaved p-n junctions is demonstrated. The resonance can be both blue- and red-shifted by applying a forward current or a negative voltage, respectively. A MZI-nested microring resonator is shown capable of
coupling tuning, enabled by a p-i-p junction based thermal heater across the waveguide. We also investigate cascaded
self-coupled optical waveguide (SCOW) resonators. Electromagnetically-induced transparency (EIT)-like resonances are
generated featuring a narrow lineshape and a high group delay. Finally, we present an athermal lattice filter made up of 10 cascaded Mach-Zehnder interferometer (MZI) units and show that the temperature sensitivity can be considerably