Ryan K. W. Lau

Silicon-Chip Mid-Infrared Frequency Comb Generation

We report the first on-chip integrated mid-infrared frequency comb using a silicon optical parametric oscillator ring resonator. We demonstrate a 750-nm-wide comb centered at 2.6 um.

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.

Broadband parametric frequency comb generation with a 1-μm pump source.

We report the first experimental demonstration of broadband frequency comb generation from a single-frequency pump laser at 1-μm using parametric oscillation in a high-Q silicon-nitride ring resonator. The resonator dispersion is engineered to have a broad anomalous group velocity dispersion region near the pump wavelength for efficient parametric four-wave mixing. The comb spans 55 THz with a 230-GHz free spectral range. These results demonstrate the powerful advantage of dispersion engineering in chip-based devices for producing combs with a wide range of pump wavelengths.

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.

Optical nonlinearities in high-confinement silicon carbide waveguides.

We demonstrate strong nonlinearities of n2=8.6±1.1×10(-15)  cm2 W(-1) in single-crystal silicon carbide (SiC) at a wavelength of 2360 nm. We use a high-confinement SiC waveguide fabricated based on a high-temperature smart-cut process.

Mid-infrared supercontinuum generation in silicon waveguides

We demonstrate supercontinuum generation (SCG) spanning from telecom to mid-infrared wavelengths beyond 3.6 μηι, using a silicon-on-insulator wire waveguide, which represents the first octave-spanning SCG from a silicon chip.

Optical nonlinearities in high confinement SiC waveguides

We demonstrate strong nonlinearities of n₂ = 8 × 10^-15 cm² W^-1 in single crystal silicon carbide at a wavelength of 2360nm. We use a high confinement SiC waveguide fabricated using a modified smart-cut process.

Four-wave mixing in Si 3 N 4 -clad silicon-on-insulator waveguides for the mid-infrared region

We introduce novel SOI waveguides with a Si3N4 top cladding for nonlinear photonics in the mid-infrared wavelength region. We demonstrate continuous-wave frequency conversion via four-wave mixing and obtain a conversion bandwidth of over 300 nm.

A broadband 1850-nm 40-Gb/s receiver based on four-wave mixing in silicon waveguides

We experimentally demonstrate a FWM-based receiver operating at long wavelengths. The scheme successfully demultiplexes a 1866-nm 40-Gb/s NRZ signal into 10-Gb/s tributaries while simultaneously wavelength-converting it to 1320 nm for photodetection.