David J. Richardson
YOU?
Author Swipe
View article: Quasi Instrumental Variable Methods for Stable Hidden Confounding and Binary Outcome
Quasi Instrumental Variable Methods for Stable Hidden Confounding and Binary Outcome Open
Instrumental variable (IV) methods are central to causal inference from observational data, particularly when a randomized experiment is not feasible. However, of the three conventional core IV identification conditions, only one, IV relev…
View article: Hollow-core fiber made of ultralow expansion glass: Toward the ultimate stability for room-temperature fiber optics
Hollow-core fiber made of ultralow expansion glass: Toward the ultimate stability for room-temperature fiber optics Open
Optical fibers have revolutionized many fields including communications, sensing, and manufacturing. Better performance and further applications are expected from emerging hollow-core fibers (HCFs) in which light propagates through a centr…
View article: Nanojoule-energy-level, polarization-maintaining, dissipative-soliton mode-locked thulium fiber laser at 1876 nm
Nanojoule-energy-level, polarization-maintaining, dissipative-soliton mode-locked thulium fiber laser at 1876 nm Open
We report an environmentally robust, dissipative-soliton, mode-locked Tm-doped fiber laser operating in the short-wavelength infrared region at 1876 nm, using all-polarization-maintaining (all-PM) fibers. Self-starting, mode-locked operati…
View article: Polarization-maintaining dissipative-soliton mode-locked thulium fiber laser with a nonlinear-amplifying-loop-mirror cavity operating at 1860 nm
Polarization-maintaining dissipative-soliton mode-locked thulium fiber laser with a nonlinear-amplifying-loop-mirror cavity operating at 1860 nm Open
We demonstrate a polarization-maintaining (PM), all-fiberized, mode-locked thulium-doped fiber laser, providing a dissipative soliton with nJ-level pulse energy. The laser has a figure-of-eight cavity with a nonlinear amplifying loop mirro…
View article: Chirp‐Managed, High‐Energy, Low‐Repetition Mamyshev Oscillator Based on Hollow Core Fiber
Chirp‐Managed, High‐Energy, Low‐Repetition Mamyshev Oscillator Based on Hollow Core Fiber Open
Mamyshev oscillator (MO) represents a powerful mode‐locking technique to produce high energy and ultrashort pulses from a fiber system. However, it is challenging to achieve low repetition rates directly from an oscillator while fully expl…
View article: Sub-nanosecond all-optically reconfigurable photonics in optical fibres
Sub-nanosecond all-optically reconfigurable photonics in optical fibres Open
We introduce a novel all-optical platform in multimode and multicore fibres. By using a low-power probe beam and a high-power counter-propagating control beam, we achieve advanced and dynamic control over light propagation within the fibre…
View article: Characterizing the SARS-CoV-2 antibody response and associations with patient factors: Serological profiling of participants enrolled in the GENCOV study
Characterizing the SARS-CoV-2 antibody response and associations with patient factors: Serological profiling of participants enrolled in the GENCOV study Open
Our findings highlight various patient factors, including vaccination, which contribute to robust, durable SARS-CoV-2 antibody responses. Overall, the findings presented here may inform future vaccine development and rollout plans.
View article: VAIR: Visuo-Acoustic Implicit Representations for Low-Cost, Multi-Modal Transparent Surface Reconstruction in Indoor Scenes
VAIR: Visuo-Acoustic Implicit Representations for Low-Cost, Multi-Modal Transparent Surface Reconstruction in Indoor Scenes Open
Mobile robots operating indoors must be prepared to navigate challenging scenes that contain transparent surfaces. This paper proposes a novel method for the fusion of acoustic and visual sensing modalities through implicit neural represen…
View article: ‘It’s not just you come into the gym and do your weight training’: a narrative exploration of muscularity’s role as identity capital
‘It’s not just you come into the gym and do your weight training’: a narrative exploration of muscularity’s role as identity capital Open
The current study explored muscularity and weight training’s role as capital in people’s identities across various contexts. Eleven weight trainers from two gyms were interviewed (3 females, 8 males) about their desires for muscularity and…
View article: Sub-nanosecond all-optically reconfigurable photonics in optical fibres
Sub-nanosecond all-optically reconfigurable photonics in optical fibres Open
We introduce a novel all-optical platform in multimode and multicore fibres. By using a low-power probe beam and a high-power counter-propagating control beam, we achieve advanced and dynamic control over light propagation within the fibre…
View article: Transient gas-induced differential refractive index effects in as-drawn hollow core optical fibers
Transient gas-induced differential refractive index effects in as-drawn hollow core optical fibers Open
When a hollow core fiber is drawn, the core and cladding holes within the internal cane geometry are pressurized with an inert gas to enable precise control over the internal microstructure of the fiber and counteract surface tension force…
View article: Double-Clad Antiresonant Hollow-Core Fiber and Its Comparison with Other Fibers for Multiphoton Micro-Endoscopy
Double-Clad Antiresonant Hollow-Core Fiber and Its Comparison with Other Fibers for Multiphoton Micro-Endoscopy Open
Label-free and multiphoton micro-endoscopy can transform clinical histopathology by providing an in situ tool for diagnostic imaging and surgical treatment in diseases such as cancer. Key to a multiphoton imaging-based micro-endoscopic dev…
View article: Coherent O-band WDM transmission of DP-16QAM over a 50-km BDFA-amplified link
Coherent O-band WDM transmission of DP-16QAM over a 50-km BDFA-amplified link Open
We present wavelength-division multiplexed coherent transmission in an O-band amplified link enabled by bismuth-doped fiber amplifiers (BDFAs). Transmission of 4 × 25 GBd DP-16QAM (4 × 200 Gb/s) is demonstrated over a single span of 50-km …
View article: Hollow‐Core Fiber: Breaking the Nonlinearity Limits of Silica Fiber in Long‐Distance Green Laser Pulse Delivery
Hollow‐Core Fiber: Breaking the Nonlinearity Limits of Silica Fiber in Long‐Distance Green Laser Pulse Delivery Open
Hollow‐core fiber (HCF), in which >99.99% of the light is guided in a central air (or vacuum) filled core, is a radically new fiber technology offering the potential to overcome the nonlinear limits associated with the delivery of high‐bri…
View article: P709: Self reported vs genetic ancestry from the GENCOV COVID-19 genomic sequencing study
P709: Self reported vs genetic ancestry from the GENCOV COVID-19 genomic sequencing study Open
The GENCOV study is a research initiative on ostensibly healthy COVID-19 positive adults in Toronto. Genomes for 1281 participants were sequenced and analyzed, and clinical characteristics were collected. GENCOV participants were surveyed …
View article: P710: Phenome-wide association study (PheWAS) for the Canadian HostSeq Biobank
P710: Phenome-wide association study (PheWAS) for the Canadian HostSeq Biobank Open
The HostSeq database is a repository containing genome sequencing (GS) results and harmonized clinical data for ∼10,000 Canadians infected with SARS-CoV-2 over the COVID-19 pandemic. HostSeq is being used to facilitate research efforts in …
View article: ‘[Trails] and tribulations’: exploring wash-out in cycling coach education
‘[Trails] and tribulations’: exploring wash-out in cycling coach education Open
The mechanisms underlying occupational socialisation and wash-out following formal coach education are not well understood. This study explores eight cycling coaches (6 males, 2 females) navigating these challenges as they transition into …
View article: Mode attraction, rejection and control in nonlinear multimode optics
Mode attraction, rejection and control in nonlinear multimode optics Open
Novel fundamental notions helping in the interpretation of the complex dynamics of nonlinear systems are essential to our understanding and ability to exploit them. In this work we predict and demonstrate experimentally a fundamental prope…
View article: High power Raman second stokes generation in a methane filled hollow core fiber
High power Raman second stokes generation in a methane filled hollow core fiber Open
We demonstrate a multi-watt, picosecond pulse duration laser source by exploiting a cascaded Raman process to the second Stokes signal at a wavelength of 2.58 μ m in a methane-filled Nested Anti-Resonant Nodeless fiber from a 1 μ m disk la…
View article: Double Clad Antiresonant Hollow Core Fiber and Its Comparison with other Fibres for Multiphoton Micro-Endoscopy
Double Clad Antiresonant Hollow Core Fiber and Its Comparison with other Fibres for Multiphoton Micro-Endoscopy Open
In this work, we study a new hollow-core (air-filled) double-clad anti-resonant fiber (DC-ARF) as a potent candidate for multiphoton micro-endoscopy. We compare the fiber characteristics with a single-clad anti-resonant fiber (SC-ARF) and …
View article: Direct VCSEL interconnection with a hollow core fiber
Direct VCSEL interconnection with a hollow core fiber Open
The direct interconnection of a hollow-core fiber (HCF) to a laser diode or photodiode is essential to full exploitation of the unique characteristics of HCFs. In this paper, we investigate two specific methods for HCF interconnection (i.e…
View article: Mode attraction, rejection and control in nonlinear multimode optics
Mode attraction, rejection and control in nonlinear multimode optics Open
Novel fundamental notions helping in the interpretation of the complex dynamics of nonlinear systems are essential to our understanding and ability to exploit them. In this work we predict and demonstrate experimentally a fundamental prope…
View article: Fiber-delivered heterodyne spectroscopy with a mid-infrared frequency comb
Fiber-delivered heterodyne spectroscopy with a mid-infrared frequency comb Open
By exploiting the excellent short-term phase stability between consecutive pulses from a free-running optical parametric oscillator frequency comb, we report the first example of hollow-core fiber-delivered heterodyne spectroscopy in the 3…
View article: Characterizing Risk Factors for Hospitalization and Clinical Characteristics in a Cohort of COVID-19 Patients Enrolled in the GENCOV Study
Characterizing Risk Factors for Hospitalization and Clinical Characteristics in a Cohort of COVID-19 Patients Enrolled in the GENCOV Study Open
The GENCOV study aims to identify patient factors which affect COVID-19 severity and outcomes. Here, we aimed to evaluate patient characteristics, acute symptoms and their persistence, and associations with hospitalization. Participants we…
View article: All-fiberized 1840-nm femtosecond thulium fiber laser for label-free nonlinear microscopy
All-fiberized 1840-nm femtosecond thulium fiber laser for label-free nonlinear microscopy Open
We report an all-fiberized 1840-nm thulium-fiber-laser source, comprising a dissipative-soliton mode-locked seed laser and a chirped-pulse-amplification system for label-free biological imaging through nonlinear microscopy. The mode-locked…
View article: Correction to “Temperature Insensitive Delay-Line Fiber Interferometer Operating at Room Temperature” [Aug 22 5716-5721]
Correction to “Temperature Insensitive Delay-Line Fiber Interferometer Operating at Room Temperature” [Aug 22 5716-5721] Open
Unfortunately, we have made a mistake on the name of co-author and missed the DOI of our dataset. It would have no influence on any of our results, and the correct name and DOI are given here.
View article: Low-latency wavelength-switched clock-synchronized intra-data center interconnects enabled by hollow core fiber
Low-latency wavelength-switched clock-synchronized intra-data center interconnects enabled by hollow core fiber Open
Fast (nanoseconds) optical wavelength switching is emerging as a viable solution to scaling the size and capacity of intra-data center interconnection. A key enabling technology for such systems is low-jitter optical clock synchronization,…
View article: 15-µJ picosecond hollow-core-fiber-feedback optical parametric oscillator
15-µJ picosecond hollow-core-fiber-feedback optical parametric oscillator Open
We report a high-energy, picosecond, mid-infrared (MIR) optical parametric oscillator (OPO), in which a length of hollow-core-fiber (HCF) is employed to enable operation at 1-MHz repetition rate in a compact cavity format. The OPO is synch…