27 research outputs found
8x8 Reconfigurable quantum photonic processor based on silicon nitride waveguides
The development of large-scale optical quantum information processing
circuits ground on the stability and reconfigurability enabled by integrated
photonics. We demonstrate a reconfigurable 8x8 integrated linear optical
network based on silicon nitride waveguides for quantum information processing.
Our processor implements a novel optical architecture enabling any arbitrary
linear transformation and constitutes the largest programmable circuit reported
so far on this platform. We validate a variety of photonic quantum information
processing primitives, in the form of Hong-Ou-Mandel interference, bosonic
coalescence/anticoalescence and high-dimensional single-photon quantum gates.
We achieve fidelities that clearly demonstrate the promising future for
large-scale photonic quantum information processing using low-loss silicon
nitride.Comment: Added supplementary materials, extended introduction, new figures,
results unchange
28 GBd PAM-8 transmission over a 100 nm range using an InP-Si3N4 based integrated dual tunable laser module
This paper describes the detailed characterization of a novel InP-Si3N4 dual laser module with results revealing relative intensity noise (RIN) as low as -165 dB/Hz and wide wavelength tunability (100 nm). The hybrid coupled laser is deployed in an unamplified 28 GBd 8 level pulse amplitude modulation (PAM) short-reach data center (DC) transmission system. System performance, which is experimentally evaluated in terms of received signal bit error ratio (BER), demonstrates the ability of the proposed laser module to support PAM-8 transmission across a 100 nm tuning range with less than 1 dB variance in receiver sensitivity over the operating wavelength range. Comparative performance studies not only indicate that the proposed source can outperform a commercial external cavity laser (ECL) in an intensity modulation/direct detection (IM/DD) link but also highlight the critical impact of RIN in the design of advanced modulation short-reach systems.Science Foundation Ireland (12/RC/2276_P2, 13/RC/2077_P2, 16/RI/3698, 18/EPSRC/3591, 18/SIRG/5579)
Ultra-narrow linewidth hybrid integrated semiconductor laser
We demonstrate a hybrid integrated and widely tunable diode laser with an
intrinsic linewidth as narrow as 40 Hz, achieved with a single roundtrip
through a low-loss feedback circuit that extends the cavity length to 0.5 meter
on a chip. Employing solely dielectrics for single-roundtrip, single-mode
resolved feedback filtering enables linewidth narrowing with increasing laser
power, without limitations through nonlinear loss. We achieve single-frequency
oscillation with up to 23 mW fiber coupled output power, 70-nm wide spectral
coverage in the 1.55 m wavelength range with 3 mW output, and obtain more
than 60 dB side mode suppression. Such properties and options for further
linewidth narrowing render the approach of high interest for direct integration
in photonic circuits serving microwave photonics, coherent communications,
sensing and metrology with highest resolution.Comment: 13 pages, and 11 figure
High-purity microwave generation using a dual-frequency hybrid integrated semiconductor-dielectric waveguide laser
We present an integrated semiconductor-dielectric hybrid dual-frequency laser
operating in the 1.5 m wavelength range for microwave and terahertz (THz)
generation. Generating a microwave beat frequency near 11 GHz, we observe a
record-narrow intrinsic linewidth as low as about 2 kHz. This is realized by
hybrid integration of a single diode amplifier based on indium phosphide (InP)
with a long, low-loss silicon nitride (SiN) feedback circuit to extend
the cavity photon lifetime, resulting in a cavity optical roundtrip length of
about 30 cm on a chip. Simultaneous lasing at two frequencies is enabled by
introducing an external control parameter for balancing the feedback from two
tunable, frequency-selective Vernier mirrors on the SiN chip. Each
frequency can be tuned with a wavelength coverage of about 80 nm, potentially
allowing for the generation of a broad range of frequencies in the microwave
range up to the THz range
Narrow linewidth hybrid InP-TriPleX photonic integrated tunable laser based on silicon nitride micro-ring resonators
Detailed characterization of a hybrid integrated tunable laser based on micro-ring resonators shows a tuning range of 50 nm with ~40 kHz linewidth. The device demonstrates performance comparable with commercial external cavity lasers in 16QAM coherent system
Design and performance estimation of a photonic integrated beamforming receiver for scan-on-receive synthetic aperture radar
Synthetic aperture radar is a remote sensing technology finding applications in a wide range of fields, especially related to Earth observation. It enables a fine imaging that is crucial in critical activities, like environmental monitoring for natural resource management or disasters prevention. In this picture, the scan-on-receive paradigm allows for enhanced imaging capabilities thanks to wide swath observations at finer azimuthal resolution achieved by beamforming of multiple simultaneous antenna beams. Recently, solutions based on microwave photonics techniques demonstrated the possibility of an efficient implementation of beamforming, overcoming some limitations posed by purely electronic solutions, offering unprecedented flexibility and precision to RF systems. Moreover, photonics-assisted RF beamformers can nowadays be realized as integrated circuits, with reduced size and power consumption with respect to digital beamforming approaches. This paper presents the design analysis and the challenges of the development of a hybrid photonic-integrated circuit as the core element of an X-band scan-on-receive spaceborne synthetic aperture radar. The proposed photonic-integrated circuit synthetizes three simultaneous scanning beams on the received signal, and performs the frequency down-conversion, guaranteeing a compact 15 cm2-form factor, less than 6 W power consumption, and 55 dB of dynamic range. The whole photonics-assisted system is designed for space compliance and meets the target application requirements, representing a step forward toward a deeper penetration of photonics in microwave applications for challenging scenarios, like the observation of the Earth from space
Hybrid integrated semiconductor lasers with silicon nitride feedback circuits
Hybrid integrated semiconductor laser sources offering extremely narrow
spectral linewidth as well as compatibility for embedding into integrated
photonic circuits are of high importance for a wide range of applications. We
present an overview on our recently developed hybrid-integrated diode lasers
with feedback from low-loss silicon nitride (Si3N4 in SiO2) circuits, to
provide sub-100-Hz-level intrinsic linewidths, up to 120 nm spectral coverage
around 1.55 um wavelength, and an output power above 100 mW. We show
dual-wavelength operation, dual-gain operation, laser frequency comb
generation, and present work towards realizing a visible-light hybrid
integrated diode laser.Comment: 25 pages, 16 figure
Nationwide comprehensive gastro-intestinal cancer cohorts: the 3P initiative
Background: The increasing sub-classification of cancer patients due to more detailed molecular classification of tumors, and limitations of current trial designs, require innovative research designs. We present the design, governance and current standing of three comprehensive nationwide cohorts including pancreatic, esophageal/gastric, and colorectal cancer patients (NCT02070146). Multidisciplinary collection of clinical data, tumor tissue, blood samples, and patient-reported outcome (PRO) measures with a nationwide coverage, provides the infrastructure for future and novel trial designs and facilitates research to improve outcomes of gastrointestinal cancer patients. Material and methods: All patients aged ≥18 years with pancreatic, esophageal/gastric or colorectal cancer are eligible. Patients provide informed consent for: (1) reuse of clinical data; (2) biobanking of primary tumor tissue; (3) collection of blood samples; (4) to be informed about relevant newly identified genomic aberrations; (5) collection of longitudinal PROs; and (6) to receive information on new interventional studies and possible participation in cohort multiple randomized controlled trials (cmRCT) in the future. Results: In 2015, clinical data of 21,758 newly diagnosed patients were collected in the Netherlands Cancer Registry. Additional clinical data on the surgical procedures were registered in surgical audits for 13,845 patients. Within the first two years, tumor tissue and blood samples were obtained from 1507 patients; during this period, 1180 patients were included in the PRO registry. Response rate for PROs was 90%. The consent rate to receive information on new interventional studies and possible participation in cmRCTs in the future was >85%. The number of hospitals participating in the cohorts is steadily increasing. Conclusion: A comprehensive nationwide multidisciplinary gastrointestinal cancer cohort is feasible and surpasses the limitations of classical study designs. With this initiative, novel and innovative studies can be performed in an efficient, safe, and comprehensive setting
Nationwide comprehensive gastro-intestinal cancer cohorts: the 3P initiative
Background: The increasing sub-classification of cancer patients due to more detailed molecular classification of tumors, and limitations of current trial designs, require innovative research designs. We present the design, governance and current standing of three comprehensive nationwide cohorts including pancreatic, esophageal/gastric, and colorectal cancer patients (NCT02070146). Multidisciplinary collection of clinical data, tumor tissue, blood samples, and patient-reported outcome (PRO) measures with a nationwide coverage, provides the infrastructure for future and novel trial designs and facilitates research to improve outcomes of gastrointestinal cancer patients. Material and methods: All patients aged ≥18 years with pancreatic, esophageal/gastric or colorectal cancer are eligible. Patients provide informed consent for: (1) reuse of clinical data; (2) biobanking of primary tumor tissue; (3) collection of blood samples; (4) to be informed about relevant newly identified genomic aberrations; (5) collection of longitudinal PROs; and (6) to receive information on new interventional studies and possible participation in cohort multiple randomized controlled trials (cmRCT) in the future. Results: In 2015, clinical data of 21,758 newly diagnosed patients were collected in the Netherlands Cancer Registry. Additional clinical data on the surgical procedures were registered in surgical audits for 13,845 patients. Within the first two years, tumor tissue and blood samples were obtained from 1507 patients; during this period, 1180 patients were included in the PRO registry. Response rate for PROs was 90%. The consent rate to receive information on new interventional studies and possible participation in cmRCTs in the future was >85%. The number of hospitals participating in the cohorts is steadily increasing. Conclusion: A comprehensive nationwide multidisciplinary gastrointestinal cancer cohort is feasible and surpasses the limitations of classical study designs. With this initiative, novel and innovative studies can be performed in an efficient, safe, and comprehensive setting
Self-mode-locking in a high-power hybrid silicon nitride integrated laser
Integrated mode-locked lasers are useful tools in microwave photonic applications as a local oscillator. In particular, hybrid integrated lasers could easily be integrated with passive processing circuits. In this Letter, we report on the self-mode-locking of a hybrid integrated laser comprising two indium phosphide gain sections and a silicon nitride feedback circuit that filters light using two ring resonators. The hybrid laser is shown to mode-lock and to have a mostly frequency-modulated field in the cavity using a stepped-heterodyne optical complex spectrum analysis. A mostly frequency modulated field output is good for high powers per line due to a more continuous emission, compared with mode-locked lasers using a saturable absorber; additionally, the filter limits the bandwidth of the comb, condensing the power to the fewer comb lines