2019 CLEO
We demonstrate the first phased array operating at blue wavelengths. We show wide-angle beam steering over a 50o field-of-view with a beam width of less than 0.17o using a high confinement silicon nitride waveguide platform.
We demonstrate miniature silicon nitride (SiN) pure phase modulators in the visible that are robust to fabrication variations. They offer a one-order-of-magnitude reduction in device footprint and power consumption compared to SiN waveguide phase shifters.
We demonstrate a platform for low-power solid-state beam steering in 2D using a single wavelength. This platform, based on a metalens and a switchable emitter array, enables steering of 12.4o×26.8o using less than 83 mW.
We demonstrate high-confinement Si3N4 resonators with intrinsic quality factor more than 1 million using standard PECVD process. We show that by addressing scattering, the loss at 1.6 μm can be as low as 0.4 dB/cm.
We demonstrate that silicon metamaterial waveguides have a high tolerance to large fabrication variations. We measured only a 5% drop in the Quality factor of a resonator with a metamaterial segment compared to a 40% drop for a wire waveguide segment, with a 50 nm discontinuity.
We demonstrate passive PT symmetry breaking between the spatial modes within a single SOI waveguide with metal deposited directly on top. By leveraging this effect, we show low propagation loss of< 1 dB for a 100 μm long, 10 μm wide waveguide partially covered with 100 nm thick metal.
We demonstrate robust mode conversion up to the 12th higher order mode in silicon waveguides by using an optimized adiabatic directional coupler and using subwavelength waveguides. The conversion efficiency is better than -1.5 dB over a 75 nm bandwidth and tolerating ±30 nm fabrication variations.
We demonstrate phase modulation in the near IR by electrostatically doping 2D semiconductor monolayers integrated on SiN waveguides. We show a VπL of 1.4 Vcm and 0.8 Vcm for MoS2 and WS2, respectively.
We report the long-term stabilization of a soliton micro-comb over 9 days of continuous operation. Using an integrated heater, the original pump-cavity detuning is maintained with a simple active feedback method.
We demonstrate continuous scanning of a single soliton micro-comb over 88 GHz with an instantaneous linewidth of 60 kHz. We show such a system can acquire spectra of HCN with a high spectral-resolution.
We demonstrate on-chip coupling between degenerate parametric oscillators (OPO’s) in two different silicon nitride microresonators. The system offers potential towards creating a network of OPO’s for the realization of a photonic coherent Ising machine.
We experimentally demonstrate soliton mode-locked Kerr comb generation at near-visible wavelengths in a silicon nitride microresonator. We achieve the shortest wavelength to-date for mode-locked Kerr combs through dispersion engineering of a higher-order mode.
We demonstrate that large pure optical phase modulation is possible in resonators operated in the strongly over-coupling regime, which suggests efficient phase modulators with high-speed operation, small footprint, low insertion loss, and low power consumption.
We experimentally demonstrate sub-harmonic synchronization of separated soliton-modelocked Kerr frequency combs. Through passive optical coupling between microresonators, we demonstrate entrainments between combs with mode spacings related by integer factors of 2 and 3.
Continuous time (CT) Electro Optic Phase Locked Loops (EOPLLs) can significantly reduce the differential delay required in a Mach-Zehnder Interferometer (MZI) which is used to detect the chirp slope, thereby reducing the MZI area and associated loss. However, CT-EOPLLs produce inter-modulation tone at (fref+fbeat) which creates spurs at offsets of ±(fref+fbeat),±2 (fref+fbeat),±3 (fref+fbeat)… from the expected beat tone at the ranging output. In this work, we present a CT-EO-PLL which not only breaks the fundamental trade-off between chirp bandwidth and MZI delay, but also completely eliminates spurs from the PLL and laser output by using IQ single-sideband (SSB) and harmonic reject (HR) mixing. This EO-PLL, integrated in CMOS technology, suppresses the spurs at beat note by> 25dB, enabling us to detect an object at a maximum range of >3.3m, with a precision of 558µm at 2m distance.
Using a single silicon-nitride waveguide, we demonstrate an f-2f interferometer for carrier-envelope-offset frequency (fCEO) detection by simultaneous supercontinuum generation and second-harmonic generation. We measure a fCEO beatnote with a 27-dB SNR with 62-pJ pulse energies.
We combine microfluidic technology with microresonator-based mid-infrared dual-comb spectroscopy. We measure flow dynamics of acetone with a spectral acquisition rate of 200-kHz over 90 cm-1 span and <150 fL sample volume over a 100-ms period.
