Hugo L. R. Lira

Broadband hitless silicon electro-optic switch for on-chip optical networks

We report on the demonstration of a broadband (60 GHz), spectrally hitless, compact (20 microm x 40 microm), fast (7 ns) electro-optical switch. The device is composed of two coupled resonant cavities, each with an independently addressable PIN diode. This topology enables operation of the switch without perturbing adjacent channels in a wavelength division multiplexing (WDM) system.

Wide-bandwidth continuously tunable optical delay line using silicon microring resonators

We demonstrate a distortion free tunable optical delay as long as 135 ps with a 10 GHz bandwidth using thermally tuned silicon microring resonators in the novel balanced configuration. The device is simple, easy to control and compact measuring only 30 µm wide by 250 µm long.

Broadband Silicon Photonic Electrooptic Switch for Photonic Interconnection Networks

We present a silicon photonic microring resonator electrooptic switch, demonstrate error-free switching of single-channel data rates up to 40 Gb/s, and characterize the device using bit-error-rate and power penalty metrics. We experimentally verify penalty-free switching of single-channel data rates up to 10 Gb/s, and low-penalty switching up to 40 Gb/s, firmly establishing the feasibility of this switch for high-performance photonic networks-on-chip.

40-Gb/s DPSK Data Transmission Through a Silicon Microring Switch

We experimentally demonstrate switching of a 40-Gb/s differential-phase-shift-keyed (DPSK) signal through a coupled silicon photonic microring switch. By simultaneously electro-optically biasing both microring cavities, we achieve 14-dB extinction ratio for signals egressing from both output ports of the switch. Packetized transmission of the 40-Gb/s DPSK signal is achieved with power penalties of 0.6 and 2.4 dB for through port and drop port signals, respectively. The effects of a coupled silicon microring are investigated, showing a broad bandwidth and a linear phase response for the drop port are necessary characteristics for routing 40-Gb/s data through the switch for photonic interconnection networks.

A hybrid optical packet and wavelength selective switching platform for high-performance data center networks

We propose and experimentally demonstrate for the first time a hybrid optical packet and wavelength selective switching platform for high-performance data center networks. This architecture based on cascaded silicon microrings and semiconductor optical amplifiers (SOAs) supports wavelength reconfigurable packet and circuit switching, and is highly scalable, energy efficient and potentially integratable. By combining the wavelength-selective behavior of the microring and the broadband behavior of the SOA switch, we are able to achieve fast switching transitions, high extinction ratios, and low driving voltages, which are all requirements for future optical high-performance data center networks. Routing correctness and error-free operation (<10(-12)) are verified for both 10-Gb/s and 40-Gb/s packets and streaming data with format transparency.

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We demonstrate simultaneous switching of wavelength-division-multiplexed (WDM) data consisting of four 44-Gb/s channels (176 Gb/s total) through an electro-optically active second-order microring switch with a 0.7-ns rise and a 3.4-ns fall time. The higher order microring device allows fast simultaneous switching of multiple high data rate WDM channels. We verify the correct active switching operation and low resultant power penalties on both switch output ports. The ability to switch multiple high data rate channels simultaneously at high speed with low power consumption makes higher order ring switches attractive components for silicon photonic switching fabrics.

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We design, fabricate and characterize a CMOS-compatible, Mach-Zehnder-coupled, second-order-microring-resonator filter with large Free Spectral Range and demonstrate non-blocking thermo-optical filter reconfiguration. The device consists of 10-μm radius silicon microring resonators, with an FSR equivalent to that of a structure consisting of 5-μm radii microrings. The structure is reconfigurable over an 8.5 nm range without blocking other channels in the network.

44 Gb/s Packet-Level Switching in a Second-Order Microring Switch

We experimentally demonstrate for the first time switching of differential-phase-shift-keyed (DPSK) signals through a silicon photonic electrooptic microring switch. DPSK format has been shown to be robust to nonlinear effects, and has 3-dB improved receiver sensitivity with balanced detection compared to the on-off-keyed format. Moreover, an extension to multilevel phase-shift-keyed (PSK) format enables higher data bandwidth. Packetized transmissions of single- and multichannel 10-Gb/s DPSK signals are demonstrated. Error-free transmission and power penalties of less than 1.7 dB are achieved for all the examined wavelength channels, confirming format transparency of the microring switch for PSK format, and validating the use of DPSK signaling for photonic interconnection networks.

CMOS compatible reconfigurable filter for high bandwidth non-blocking operation.

Error-free switching of up to 40-Gb/s data using a silicon photonic microring resonator electro-optic switch is demonstrated for the first time, with bit-error-rate and power penalty characterizations firmly establishing its feasibility for high-performance photonic networks-on-chip.

DPSK Transmission Through Silicon Microring Switch for Photonic Interconnection Networks

We present a broadband packet-switching node that utilizes silicon photonic technology. The node design uses a silicon microring for switching functionality, leverages in-flight header processing for arbitration, and has a tunable driving circuit for thermal-effect mitigation. Moreover, these integrated microring switches are capable of scaling to tremendously high port counts in a compact area, which are attractive for data-center networks. We experimentally characterize the extinction ratio of the switch for varying packet durations, interarrival times, and driving voltages and demonstrate an error-free routing of 10-Gb/s wavelength-striped packets with lengths of up to 1536 ns. We further study the resonance thermal drifting for long- hold-time packet switching through carrier injection and show thermal-effect mitigation using a pre-emphasized gating signal.