A reconfigurable microwave photonic filter (MPF) based on an integrated Kerr comb source was proposed and
demonstrated. By employing an on-chip micro-ring resonator (MRR), a broadband Kerr comb with a large number of
comb lines was generated and used as a high-quality multi-wavelength source for the MPF, which greatly reduced the size
and cost. The enhanced performance of the MPF was theoretically analysed and systematically characterized. Due to the
large channel number and high reconfigurability of the scheme, the MPF features an improved Q factor and wideband
tunability. The experimental results matches well with theory, verifying the feasibility of our approach as a solution towards
implementing highly reconfigurable MPFs with reduced system complexity.
An arbitrary-order intensity differentiator for high-order microwave signal differentiation is proposed and experimentally demonstrated on a versatile transversal microwave photonic signal processing platform based on integrated Kerr combs. With a CMOS-compatible nonlinear micro-ring resonator, high quality Kerr combs with broad bandwidth and large frequency spacings are generated, enabling a larger number of taps and an increased Nyquist zone. By programming and shaping individual comb lines’ power, calculated tap weights are realized, thus achieving a versatile microwave photonic signal processing platform. Arbitrary-order intensity differentiation is demonstrated on the platform. The RF responses are experimentally characterized, and systems demonstrations for Gaussian input signals are also performed.
Photonic integrated circuits that exploit nonlinear optics in order to generate and process signals all-optically have achieved performance far superior to that possible electronically - particularly with respect to speed. We review the recent achievements based in new CMOS-compatible platforms that are better suited than SOI for nonlinear optics, focusing on radio frequency (RF) and microwave based applications that exploit micro-resonator based frequency combs. We highlight their potential as well as the challenges to achieving practical solutions for many key applications. These material systems have opened up many new capabilities such as on-chip optical frequency comb generation and ultrafast optical pulse generation and measurement. We review recent work on a photonic RF Hilbert transformer for broadband microwave in-phase and quadrature-phase generation based on an integrated frequency optical comb. The comb is generated using a nonlinear microring resonator based on a CMOS compatible, high-index contrast, doped-silica glass platform. The high quality and large frequency spacing of the comb enables filters with up to 20 taps, allowing us to demonstrate a quadrature filter with more than a 5-octave (3 dB) bandwidth and an almost uniform phase response.
We present a new approach to planar photonic interconnects based on spatial adiabatic passage between thin ridge silicon waveguides. Our approach provides robust coupling between arbitrary pairs of well-separated waveguides across a single chip, potentially bypassing intermediate waveguides and structures. This new technique presents opportunities for waveguide routing and device topologies that cannot be achieved using traditional evanescent coupling, while remaining compatible with conventional CMOS fabrication techniques.
This paper reports on the conceptual design and simulation of a new hybrid coupled plasmon/dielectric waveguide
device which may present opportunities for biosensing. The operation of the device is based on the phase matching
of wave propagation in the dielectric waveguide with that of the surface plasmons. Finite element method (FEM)
and eigenmode expansion (EME) methods have been utilised to analyse the characteristics of propagation of
these waves. A suitable periodic grating structure has been implemented to provide wavelength dependent phase
matching between the dielectric and plasmon modes. The selectivity of plasmon coupling makes it an ideal
technology to be utilised for sensing. Such a device may be fabricated as a low cost, highly sensitive, integratable
sensor allowing the detection of finite environmental changes including the presence of single layers of molecules.
We report on the design and simulation of a novel Silicon-On-Insulator waveguide structures which when excited with
TM guided light, emit TE polarized radiation with controlled radiation characteristics. The structures utilize parallel
leaky waveguides of specific separations. The structures are simulated using a full-vector mode-matching approach
which allows visualisation of the evolution of the propagating and radiating fields over the length of the waveguide
structure. It is shown that radiation can be resonantly enhanced or suppressed in different directions depending on the
choice of the phase of the excitation of the waveguide components. Steps toward practical demonstration are identified.
This paper demonstrates the structural optimization using Evolutionary Algorithms in a chalcogenide glass
waveguide. Four features are taken into consideration while optimizing the waveguide structure, they include:
single-mode, low dispersion, high nonlinearity and low loss. A set of waveguide structures which meet the
design criteria are shown in the paper. The best structure enhances the nonlinear coefficient to 26000 /W/km
at telecom wavelength. In this work, we demonstrate the methodology used to optimize waveguide as well as
the procedure of conducting the experiment.