1,146 research outputs found
All-integrated universal RF photonic spectral shaper
We demonstrate a microwave photonic spectral shaper in a silicon chip enabling distinct phase and amplitude modulation transformation. We show unprecedented RF filtering through monolithic integration of the spectral shaper with tunable ring resonators
Photonic RF and microwave reconfigurable filters and true time delays based on an integrated optical Kerr frequency comb source
We demonstrate advanced transversal radio frequency (RF) and microwave
functions based on a Kerr optical comb source generated by an integrated
micro-ring resonator. We achieve extremely high performance for an optical true
time delay aimed at tunable phased array antenna applications, as well as
reconfigurable microwave photonic filters. Our results agree well with theory.
We show that our true time delay would yield a phased array antenna with
features that include high angular resolution and a wide range of beam steering
angles, while the microwave photonic filters feature high Q factors, wideband
tunability, and highly reconfigurable filtering shapes. These results show that
our approach is a competitive solution to implementing reconfigurable, high
performance and potentially low cost RF and microwaveComment: 15 pages, 11 Figures, 60 Reference
High performance photonic microwave filters based on a 50GHz optical soliton crystal Kerr micro-comb
We demonstrate a photonic radio frequency (RF) transversal filter based on an
integrated optical micro-comb source featuring a record low free spectral range
of 49 GHz yielding 80 micro-comb lines across the C-band. This record-high
number of taps, or wavelengths for the transversal filter results in
significantly increased performance including a QRF factor more than four times
higher than previous results. Further, by employing both positive and negative
taps, an improved out-of-band rejection of up to 48.9 dB is demonstrated using
Gaussian apodization, together with a tunable centre frequency covering the RF
spectra range, with a widely tunable 3-dB bandwidth and versatile dynamically
adjustable filter shapes. Our experimental results match well with theory,
showing that our transversal filter is a competitive solution to implement
advanced adaptive RF filters with broad operational bandwidths, high frequency
selectivity, high reconfigurability, and potentially reduced cost and
footprint. This approach is promising for applications in modern radar and
communications systems.Comment: 19 pages, 12 figures, 107 reference
Emerging applications of integrated optical microcombs for analogue RF and microwave photonic signal processing
We review new applications of integrated microcombs in RF and microwave
photonic systems. We demonstrate a wide range of powerful functions including a
photonic intensity high order and fractional differentiators, optical true time
delays, advanced filters, RF channelizer and other functions, based on a Kerr
optical comb generated by a compact integrated microring resonator, or
microcomb. The microcomb is CMOS compatible and contains a large number of comb
lines, which can serve as a high performance multiwavelength source for the
transversal filter, thus greatly reduce the cost, size, and complexity of the
system. The operation principle of these functions is theoretically analyzed,
and experimental demonstrations are presented.Comment: 16 pages, 8 figures, 136 References. Photonics West 2018 invited
paper, expanded version. arXiv admin note: substantial text overlap with
arXiv:1710.00678, arXiv:1710.0861
Low-error and broadband microwave frequency measurement in a silicon chip
Instantaneous frequency measurement (IFM) of microwave signals is a
fundamental functionality for applications ranging from electronic warfare to
biomedical technology. Photonic techniques, and nonlinear optical interactions
in particular, have the potential to broaden the frequency measurement range
beyond the limits of electronic IFM systems. The key lies in efficiently
harnessing optical mixing in an integrated nonlinear platform, with low losses.
In this work, we exploit the low loss of a 35 cm long, thick silicon waveguide,
to efficiently harness Kerr nonlinearity, and demonstrate the first on-chip
four-wave mixing (FWM) based IFM system. We achieve a large 40 GHz measurement
bandwidth and record-low measurement error. Finally, we discuss the future
prospect of integrating the whole IFM system on a silicon chip to enable the
first reconfigurable, broadband IFM receiver with low-latency.Comment: 13 pages, 7 figure
Harnessing optical micro-combs for microwave photonics
In the past decade, optical frequency combs generated by high-Q
micro-resonators, or micro-combs, which feature compact device footprints, high
energy efficiency, and high-repetition-rates in broad optical bandwidths, have
led to a revolution in a wide range of fields including metrology, mode-locked
lasers, telecommunications, RF photonics, spectroscopy, sensing, and quantum
optics. Among these, an application that has attracted great interest is the
use of micro-combs for RF photonics, where they offer enhanced functionalities
as well as reduced size and power consumption over other approaches. This
article reviews the recent advances in this emerging field. We provide an
overview of the main achievements that have been obtained to date, and
highlight the strong potential of micro-combs for RF photonics applications. We
also discuss some of the open challenges and limitations that need to be met
for practical applications.Comment: 32 Pages, 13 Figures, 172 Reference
Multifunctional photonic integrated circuit for diverse microwave signal generation, transmission and processing
Microwave photonics (MWP) studies the interaction between microwave and
optical waves for the generation, transmission and processing of microwave
signals (i.e., three key domains), taking advantages of broad bandwidth and low
loss offered by modern photonics. Integrated MWP using photonic integrated
circuits (PICs) can reach a compact, reliable and green implementation. Most
PICs, however, are recently developed to perform one or more functions
restricted inside a single domain. In this paper, as highly desired, a
multifunctional PIC is proposed to cover the three key domains. The PIC is
fabricated on InP platform by monolithically integrating four laser diodes and
two modulators. Using the multifunctional PIC, seven fundamental functions
across microwave signal generation, transmission and processing are
demonstrated experimentally. Outdoor field trials for electromagnetic
environment surveillance along an in-service high-speed railway are also
performed. The success to such a PIC marks a key step forward for practical and
massive MWP implementations.Comment: 17 page
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