Michael Menard

Continuous-wave mid-infrared frequency conversion in silicon nanowaveguides

We report continuous-wave wavelength conversion from the telecom band to the mid-infrared via four-wave mixing in silicon nanowaveguides. We convert a 1636-nm signal to produce a 2384-nm idler, demonstrating a parametric bandwidth of 748 nm.

First Demonstration of a 10-Gb/s RZ End-to-End Four-Wave-Mixing Based Link at 1884 nm Using Silicon Nanowaveguides

We demonstrate a double-stage four-wave mixing (FWM) scheme in silicon nanowaveguides which allows effective optical time-division-multiplexed data generation and reception in the 2-μm region. The scheme is based on a first mixing stage which unicasts a high-speed return-to-zero stream from the C-band to 1884-nm, followed by a second mixing stage which wavelength converts the data from 1884-nm down to the O-band for detection. The 10-Gb/s data traverses an aggregate record distance of 909 nm in the cascaded wavelength-conversion and unicast stages, with a power penalty of 2.5 dB. This scheme effectively overcomes the lack of commercially-available high-performance sources and receivers at 2 μm by relying on telecommunication band components along with ultrabroad FWM silicon devices.

Wavelength conversion and unicast of 10-Gb/s data spanning up to 700 nm using a silicon nanowaveguide.

We report extremely large probe-idler separation wavelength conversion (545 nm) and unicast (700 nm) of 10-Gb/s data signals using a dispersion-engineered silicon nanowaveguide. Dispersion-engineered phase matching in the device provides a continuous four-wave-mixing efficiency 3-dB bandwidth exceeding 800 nm. We report the first data validation of wavelength conversion (data modulated probe) and unicast (data modulated pump) of 10-Gb/s data with probe-idler separations spanning 60 nm up to 700 nm accompanied with sensitivity gain in a single device. These demonstrations further validate the silicon platform as a highly broadband flexible platform for nonlinear all-optical data manipulation.

Simultaneous wavelength conversion of ASK and DPSK signals based on four-wave-mixing in dispersion engineered silicon waveguides.

We experimentally demonstrate four-wave-mixing (FWM)-based continuous wavelength conversion of optical differential-phase-shift-keyed (DPSK) signals with large wavelength conversion ranges as well as simultaneous wavelength conversion of dual-wavelength channels with mixed modulation formats in 1.1-cm-long dispersion-engineered silicon waveguides. We first validate up to 100-nm wavelength conversion range for 10-Gb/s DPSK signals, showcasing the capability to perform phase-preserving operations at high bit rates in chip-scale devices over wide conversion ranges. We further validate the wavelength conversion of dual-wavelength channels modulated with 10-Gb/s packetized phase-shift-keyed (PSK) and amplitude-shift-keyed (ASK) signals; demonstrate simultaneous operation on multiple channels with mixed formats in chip-scale devices. For both configurations, we measure the spectral and temporal responses and evaluate the performances using bit-error-rate (BER) measurements.

Rotational MEMS mirror with latching arm for silicon photonics

We present an innovative rotational MEMS mirror that can control the direction of propagation of light beams inside of planar waveguides implemented in silicon photonics. Potential applications include but are not limited to optical telecommunications, medical imaging, scan and spectrometry. The mirror has a half-cylinder shape with a radius of 300 μm that provides low and constant optical losses over the full angular displacement range. A circular comb drive structure is anchored such that it allows free or latched rotation experimentally demonstrated over 8.5° (X-Y planar rotational movement) using 290V electrostatic actuation. The entire MEMS structure was implemented using the MEMSCAP SOIMUMPs process. The center of the anchor beam is designed to be the approximate rotation point of the circular comb drive to counter the rotation offset of the mirror displacement. A mechanical characterization of the MEMS mirror is presented. The latching mechanism provides up to 20 different angular locking positions allowing the mirror to counter any resonance or vibration effects and it is actuated with an electrostatic linear comb drive. An innovative gap closing structure was designed to reduce optical propagation losses due to beam divergence in the interstitial space between the mirror and the planar waveguide. The gap closing structure is also electrostatically actuated and includes two side stoppers to prevent stiction.

Integrated Fabry-Perot Comb Filters for Optical Space Switching

The first implementation of an integrated filter for optical space switching based on coupled Fabry-Perot cavities built in a planar waveguide and working at oblique incidence is presented in this paper. Parabolic mirrors are used to collimate and direct light into a filter defined by deep etching in a GaAs waveguide and formed of four high-order cavities that provide a 200 GHz comb response. The filter has a theoretical passband bandwidth of more than 50 GHz and allows the switch to work over an entire wavelength band. It was possible to contain 50 channels of the International Telecommunication Union 100 GHz grid within the filter response. Bit error rate tests at 10 Gb/s were performed to evaluate the switch power penalty. To assess the scalability of this switch design, crossbar and shuffle Benes¿ layout for devices with 2-16 ports were optimized. The dominating factor that limits the minimization of a switch fabric area is the beam waist required to avoid distortion by the filters.

An integrated silicon-on-insulator continually tunable optical delay line for optical coherence tomography

We describe a new integrated rapidly tunable optical delay line optimized for optical coherence tomography (OCT) systems. The integrated system uses a planar waveguide and echelle gratings combined with a specially designed micro-electromechanical system (MEMS) mirror. These components are all fabricated on the same die, thus enabling a very compact and cost effective device. The delay line system has a simulated scanning speed of more than 10 kHz and can provide a continuously tunable variable delay difference of 6.7 ps. The whole system fits on a chip of 12 mm by 8 mm.

Two-period contra-directional grating assisted coupler.

We present the design, analysis, and experimental characterization of a novel integrated add-drop filter capable of filtering simultaneously two independent channels that is based on a contra-directional grating assisted coupler with two different periods. The device performance is explained using Fourier analysis and confirmed with numerical simulations using the eigenmode expansion method. The devices were fabricated using electron-beam lithography on a silicon-on-insulator wafer with a 220 nm thick device layer. The Fourier analysis, simulations and experimental results are in agreement and show that the drop port response of the two-period configuration is the superposition of the drop port responses of two single-period gratings. Therefore, the output channels at drop port can be designed independently and can have different bandwidths.

Chip-scale broadband optical isolation via Bragg scattering four-wave mixing

We report the first demonstration of a broadband optical isolation using a Silicon nanowaveguide via Bragg scattering four-wave mixing. We achieve an isolation ratio of 4 dB over a bandwidth of 8 nm.

Waveguide-based single-shot temporal cross-correlator

We describe a novel technique for performing a single-shot optical cross-correlation in nanowaveguides. Our scheme is based on four-wave mixing (FWM) between two orthogonally polarized input signals propagating with different velocities due to polarization mode dispersion. The cross-correlation is determined by measuring the spectrum of the idler wave generated by the FWM process.