Bart Kuyken

Mid-infrared to telecom-band supercontinuum generation in highly nonlinear silicon-on-insulator wire waveguides

We demonstrate the generation of a supercontinuum in a 2 cm long silicon wire by pumping the wire with mid-infrared picosecond pulses in the anomalous dispersion regime. The supercontinuum extends from 1535 nm up to 2525 nm for a coupled peak power of 12.7 W. It is shown that the supercontinuum originates primarily from the amplification of background noise. A detailed analysis of the spectral components which are generated through phase-matched processes is applied to extract the group velocity dispersion and fourth-order dispersion coefficient of the silicon wire waveguide.

Nonlinear properties of and nonlinear processing in hydrogenated amorphous silicon waveguides

We propose hydrogenated amorphous silicon nanowires as a platform for nonlinear optics in the telecommunication wavelength range. Extraction of the nonlinear parameter of these photonic nanowires reveals a figure of merit larger than 2. It is observed that the nonlinear optical properties of these waveguides degrade with time, but that this degradation can be reversed by annealing the samples. A four wave mixing conversion efficiency of + 12 dB is demonstrated in a 320 Gbit/s serial optical waveform data sampling experiment in a 4 mm long photonic nanowire.

Interaction between light and highly confined hypersound in a silicon photonic nanowire

The authors experimentally and theoretically demonstrate stimulated Brillouin scattering in a silicon nanowire supported by a pillar, which results from the tight confinement of both photons and phonons.

On-chip parametric amplification with 26.5 dB gain at telecommunication wavelengths using CMOS-compatible hydrogenated amorphous silicon waveguides

We present what we believe to be the first study of parametric amplification in hydrogenated amorphous silicon waveguides. Broadband on/off amplification up to 26.5 dB at telecom wavelength is reported. Measured nonlinear parameter is 770 W(-) m(-1), nonlinear absorption 28 W(-1)  m(-1), bandgap 1.61 eV.

An octave-spanning mid-infrared frequency comb generated in a silicon nanophotonic wire waveguide

Laser frequency combs, sources with a spectrum consisting of hundred thousands evenly spaced narrow lines, have an exhilarating potential for new approaches to molecular spectroscopy and sensing in the mid-infrared region. The generation of such broadband coherent sources is presently under active exploration. Technical challenges have slowed down such developments. Identifying a versatile highly nonlinear medium for significantly broadening a mid-infrared comb spectrum remains challenging. Here we take a different approach to spectral broadening of mid-infrared frequency combs and investigate CMOS-compatible highly nonlinear dispersion-engineered silicon nanophotonic waveguides on a silicon-on-insulator chip. We record octave-spanning (1,500–3,300 nm) spectra with a coupled input pulse energy as low as 16 pJ. We demonstrate phase-coherent comb spectra broadened on a room-temperature-operating CMOS-compatible chip.

Bridging the mid-infrared-to-telecom gap with silicon nanophotonic spectral translation

Efficient four-wave-mixing process in silicon nanophotonic wires facilitates spectral translation of a signal at 2,440 nm to the telecommunications band at 1,620 nm across a span of 62 THz. This approach helps eliminate cooling requirements for the narrow-bandgap semiconductors traditionally used to detect mid-infrared photons.

Silicon-Based Photonic Integration Beyond the Telecommunication Wavelength Range

In this paper we discuss silicon-based photonic integrated circuit technology for applications beyond the telecommunication wavelength range. Silicon-on-insulator and germanium-on-silicon passive waveguide circuits are described, as well as the integration of III-V semiconductors, IV-VI colloidal nanoparticles and GeSn alloys on these circuits for increasing the functionality. The strong nonlinearity of silicon combined with the low nonlinear absorption in the mid-infrared is exploited to generate picosecond pulse based supercontinuum sources, optical parametric oscillators and wavelength translators connecting the telecommunication wavelength range and the mid-infrared.

Demonstration of silicon-on-insulator mid-infrared spectrometers operating at 3.8 um

The design and characterization of silicon-on-insulator mid-infrared spectrometers operating at 3.8 μm is reported. The devices are fabricated on 200 mm SOI wafers in a CMOS pilot line. Both arrayed waveguide grating structures and planar concave grating structures were designed and tested. Low insertion loss (1.5-2.5 dB) and good crosstalk characteristics (15-20 dB) are demonstrated, together with waveguide propagation losses in the range of 3 to 6 dB/cm.

50 dB parametric on-chip gain in silicon photonic wires

A pulsed mid-infrared pump at λ=2173 nm is used to demonstrate wideband optical parametric gain in a low-loss 2 cm long silicon photonic wire. Using dispersion engineering to obtain negative second-order (β2) and positive fourth-order (β4) dispersion, we generate broadband modulation instability and parametric fluorescence extending from 1911 nm-2486 nm. Using a cw probe signal to interrogate the modulation instability spectrum, we demonstrate parametric amplification >40 dB with an on-chip gain bandwidth wider than 580 nm, as well as narrowband Raman-assisted peak gain >50 dB.

Silicon-based heterogeneous photonic integrated circuits for the mid-infrared

In this paper we present our recent work on mid-infrared photonic integrated circuits for spectroscopic sensing applications. We discuss the use of silicon-based photonic integrated circuits for this purpose and detail how a variety of optical functions in the mid-infrared besides passive waveguiding and filtering can be realized, either relying on nonlinear optics or on the integration of other materials such as GaSb-based compound semiconductors, GeSn epitaxy and PbS colloidal nanoparticles.