In this thesis, we propose and demonstrate microresonator-based electro-optical tunable switches and optical delay lines for on-chip optical interconnects....[ Read more ]

In this thesis, we propose and demonstrate microresonator-based electro-optical tunable switches and optical delay lines for on-chip optical interconnects.

On the matrix switch front, we analyze the design of the microring resonator-based switch element to meet the bandwidth and low power consumption requirements. For proof-of-principle, we demonstrate the electro-optical tunable cross-connect microring resonator-based optical switch element, showing nanosecond switching speed and submilliwatt DC power consumption. We also demonstrate a 2 × 2 matrix switch, showing 5-Gbit/s data routing as desired between multiple signal inputs and outputs without significant distortion.

On the optical delay lines front, we show the electro-optical tunable time delay and advance using two different microring resonator-based configurations. In one configuration using microring-resonator based notch filter, we demonstrate the time delay and advance tunability by controlling the coupling condition from over-coupling to under-coupling regimes. The demonstrated maximum time delay and advance are ~ 95 ps with bandwidth of ~ 3.0 GHz, showing the time-bandwidth product of ~ 0.3. In another configuration using feedback waveguide-coupled microring resonator, we demonstrated time delay and advance tunability by controlling the feedback waveguide phase change. The demonstrated time delay and advance are ~ 100 ps with bandwidth of ~ 3.5 GHz, showing a time-bandwidth of ~ 0.35. We also show wavelength-tunable time delay and advance using this configuration.

We propose and demonstrate coupled-resonator optical waveguide (CROW) delay lines using microspiral and double-notch-shaped microdisk resonators. The merit of our proposed CROW is the gapless inter-cavity coupling with only ~ 0.11-0.24 dB/disk insertion loss. We demonstrate such CROWs with up to 101 cascaded microdisks, showing pronounced high-order filter response with larger than 20 GHz bandwidth and high side-mode suppression ratio. The demonstrated maximum time delay is ~ 70 ps and ~110 ps in a ~20 GHz transmission band center and band edge, suggesting an enhanced time-bandwidth product of ~1.4.