In certain materials, the linear electro-optic (Pockels) effect allows direct control of the refractive index with an applied electric field. In practice, material inhomogeneities and defects cause the field inside the material to drift over macroscopic time scales. Such phenomena degrade the reliability and stability of integrated electro-optic devices. Here, we combine systematic measurements of dc electro-optic response, electronic transport, and elemental composition to examine the microscopic origins of dc instability in nanofabricated thin-film lithium niobate (TFLN) devices. We identify two key sources of instability: the metal-LN contact interface where Schottky barriers impede charge injection, and the oxide-LN cladding interface where lithium diffusion occurs. Our work provides an electronic understanding of a long-standing photonics issue, advancing a potential pathway toward high-performance integrated electro-optic devices through materials-motivated design.

Electro-optics serves as the crucial bridge between electronics and photonics, unlocking a wide array of applications ranging from communications and computing to sensing and quantum information. Integrated electro-optics approaches in particular enable essential electronic high-speed control for photonics while offering substantial photonic parallelism for electronics. Recent strides in thin-film lithium niobate photonics have ushered revolutionary advancements in electro-optics. This technology not only offers the requisite strong electro-optic coupling but also boasts ultra-low optical loss and high microwave bandwidth. Further, its tight confinement and compatibility with nanofabrication allow for unprecedented reconfigurability and scalability, facilitating the creation of novel and intricate devices and systems that were once deemed nearly impossible in bulk systems. Building upon this platform, the field has witnessed the emergence of various groundbreaking electro-optic devices surpassing the current state of the art, and introducing functionalities that were previously non-existent. This technological leap forward provides a unique framework to explore various realms of physics as well, including photonic non-Hermitian synthetic dimensions, active topological physics, and quantum electro-optics. In this review, we present the fundamental principles of electro-optics, drawing connections between fundamental science and the forefront of technology. We discuss the accomplishments and future prospects of integrated electro-optics, enabled by thin-film lithium niobate platform.

Quantum science and technology promise the realization of a powerful computational resource that relies on a network of quantum processors connected with low loss and low noise communication channels capable of distributing entangled states [1,2]. While superconducting microwave qubits (3-8 GHz) operating in cryogenic environments have emerged as promising candidates for quantum processor nodes due to their strong Josephson nonlinearity and low loss [3], the information between spatially separated processor nodes will likely be carried at room temperature via telecommunication photons (200 THz) propagating in low loss optical fibers. Transduction of quantum information [4-10] between these disparate frequencies is therefore critical to leverage the advantages of each platform by interfacing quantum resources. Here, we demonstrate coherent optical control of a superconducting qubit. We achieve this by developing a microwave-optical quantum transducer that operates with up to 1.18% conversion efficiency (1.16% cooperativity) and demonstrate optically-driven Rabi oscillations (2.27 MHz) in a superconducting qubit without impacting qubit coherence times (800 ns). Finally, we discuss outlooks towards using the transducer to network quantum processor nodes.

We report on near-infrared thin-film lithium niobate devices for scaling up quantum nodes. We demonstrate integrated low-insertion loss couplers, frequency shifters, laser pulse generators, switches, and more.

We report on the controlled generation and annihilation of defects in photonic platforms using low-energy electron beams. We show how these defects impact propagation losses and EO-stability in LNOI, and how they can be rectified.

We describe coherent optical control of a superconducting qubit with an electro-optic transducer as a step towards enabling optical interconnects between superconducting processor nodes.

We demonstrate a technique allowing scalable integration of III-V lasers on thin-film lithium niobate platform. Our method relies on an unconventional growth of the III-V epitaxial layer such that the n-layer ends on the top.

We demonstrate efficient dispersion management in integrated lithium niobate on insulator. Using a chirped Bragg grating in an integrated electro-optic time lens, we generate femtosecond 545 fs pulses entirely on-chip.

Abstract This article reports findings from a study that sought to identify barriers to music and music education in the UK. Emerging from empirical research involving n = 723 participants and clarified by an evidence base of over 10,000 research participants, the key findings presented in this paper relate to pupil and participant voice and involvement, location as a sub-theme of diversity and inclusion, collaboration and transition points. The research is contextualised by twenty years of policy initiatives seeking to address barriers to music learning. The article provides an overview of the research study before presenting the rich data that emerged within each theme reported. Research participant voice is used as much as possible to enable the reader to consider, reflect and interpret the data in a way that is meaningful for their own context. The paper concludes by asking why after 20 years of policy initiatives, research and evaluation the same barriers still exist and, as we emerge from the pandemic, suggests that this research provides a compelling case that now is the time for change.

Dynamically reconfigurable metasurfaces promise compact and lightweight spatial light modulation for many applications, including LiDAR, AR/VR, and LiFi systems. Here, we design and computationally investigate high-quality-factor silicon-on-lithium niobate metasurfaces with electrically driven, independent control of its constituent nanobars for full phase tunability with high tuning efficiency. Free-space light couples to guided modes within each nanobar via periodic perturbations, generating quality factors exceeding 30,000 while maintaining a bar spacing of <λ/1.5. We achieve nearly 2π phase variation with an applied bias not exceeding ±25 V, maintaining a reflection efficiency above 91%. Using full-field simulations, we demonstrate a high-angle (51°) switchable beamsplitter with a diffracted efficiency of 93% and an angle-tunable beamsteerer, spanning 18-31°, with up to 86% efficiency, all using the same metasurface device. Our platform provides a foundation for highly efficient wavefront-shaping devices with a wide dynamic tuning range capable of generating nearly any transfer function.

Integrated femtosecond pulse and frequency comb sources are critical components for a wide range of applications. The leading approaches for on-chip pulse generation rely on mode locking inside microresonator with either third-order nonlinearity or with semiconductor gain. These approaches, however, are limited in noise performance, wavelength tunability and repetition rates. Alternatively, sub-picosecond pulses can be synthesized without mode-locking, by modulating a continuous-wave (CW) single-frequency laser using a cascade of electro-optic (EO) modulators. This method is particularly attractive due to its simplicity, robustness, and frequency-agility but has been realized only on a tabletop using multiple discrete EO modulators and requiring optical amplifiers (to overcome large insertion losses), microwave amplifiers, and phase shifters. Here we demonstrate a chip-scale femtosecond pulse source implemented on an integrated lithium niobate (LN) photonic platform18, using cascaded low-loss electro-optic amplitude and phase modulators and chirped Bragg grating, forming a time-lens system. The device is driven by a CW distributed feedback (DFB) chip laser and controlled by a single CW microwave source without the need for any stabilization or locking. We measure femtosecond pulse trains (520 fs duration) with a 30-GHz repetition rate, flat-top optical spectra with a 10-dB optical bandwidth of 12.6 nm, individual comb-line powers above 0.1 milliwatt, and pulse energies of 0.54 picojoule. Our results represent a tunable, robust and low-cost integrated pulsed light source with CW-to-pulse conversion efficiencies an order of magnitude higher than achieved with previous integrated sources. Our pulse generator can find applications from ultrafast optical measurement to networks of distributed quantum computers.

Here we present high quality factor (high-Q) metasurfaces as a new platform for continuous, electro-optical reconfigurability. Using full-field simulations, we show how applying a voltage across individual nanoantenna shifts the spectral position of the high-Q resonance, modifying the antenna phase and amplitude, and achieving a full 2 pi phase variation with reflectance above 93%. We next computationally design a modulatable beam steerer; without bias light is directly reflected from the metasurface, whereas with applied biases of +9.2, 0, and -9.2 V across three constituent antennas the light is diffracted to 30 deg with 65% efficiency. Biases of 13, 2, -2, and -13 V across 4 constituent antennas diffract to 22 deg. Our presentation will discuss not only the design but also fabrication and characterization en route to a versatile metasurface platform that can reconfigurably achieve a variety of transfer functions.

BACKGROUND:Vesicoureteral reflux (VUR) is a common, familial genitourinary disorder, and a major cause of pediatric urinary tract infection (UTI) and kidney failure. The genetic basis of VUR is not well understood. METHODS:A diagnostic analysis sought rare, pathogenic copy number variant (CNV) disorders among 1737 patients with VUR. A GWAS was performed in 1395 patients and 5366 controls, of European ancestry. RESULTS:Altogether, 3% of VUR patients harbored an undiagnosed rare CNV disorder, such as the 1q21.1, 16p11.2, 22q11.21, and triple X syndromes ((OR, 3.12; 95% CI, 2.10 to 4.54; P=6.35×10-8) The GWAS identified three study-wide significant and five suggestive loci with large effects (ORs, 1.41-6.9), containing canonical developmental genes expressed in the developing urinary tract (WDPCP, OTX1, BMP5, VANGL1, and WNT5A). In particular, 3.3% of VUR patients were homozygous for an intronic variant in WDPCP (rs13013890; OR, 3.65; 95% CI, 2.39 to 5.56; P=1.86×10-9). This locus was associated with multiple genitourinary phenotypes in the UK Biobank and eMERGE studies. Analysis of Wnt5a mutant mice confirmed the role of Wnt5a signaling in bladder and ureteric morphogenesis. CONCLUSIONS:These data demonstrate the genetic heterogeneity of VUR. Altogether, 6% of patients with VUR harbored a rare CNV or a common variant genotype conferring an OR >3. Identification of these genetic risk factors has multiple implications for clinical care and for analysis of outcomes in VUR.

Cystic fibrosis (CF) is the most common life-limiting autosomal recessive disease in the Republic of Ireland (ROI), with a previously quoted incidence of 1 in 1353 and carrier rate of 1 in 19. The National Newborn Screening (NBS) for CF was incorporated in July 2011 in the ROI. A cut-off point of the top 1% Immunoreactive Trypsinogen (IRT) was taken as an indication for 38 CFTR variant panel to maximise identification of affected CF cases and to minimise detection of carriers. All neonates from July 2011 to Dec 2017 with an elevated IRT on NBS were tested with 38 CFTR mutation panel and included. Clinical and laboratory database were analysed. In the first 6.5 years a total of 5,053 newborns (1.16% of total births) were screened with 38 CFTR panel. 170 CF affected cases, 320 unaffected carriers, 32 CF Screening Positive Inconclusive Diagnosis (CFSPID) were identified. There was one missed diagnosis. The most common disease-causing variant was c.1521_1523delCTT (p.(Phe508del)) followed by c.1652G>A (p.(Gly551Asp)). 95 out of 170 (55%) affected newborns were homozygous for c.1521_1523delCTT (p.(Phe08del)) and 25 (15%) carried at least one copy of c.1652G>A (p.(Gly551Asp)). Hence, 70% of affected newborns were eligible for CFTR modulator treatment. The NBS programme has identified almost triple the number of affected newborn with c.1652G>A (p.(Gly551Asp)) than previously quoted figures and identified less than 50% of carriers than predicted. The revised incidence and carrier frequency of CF in the ROI is 1 in 2570 and 1 in 25, respectively.

Densely interconnected, nonlinear, and reconfigurable optical networks represent a route to highperformance optical computing, communications, and sensing technologies. Dielectric nanoantennas are promising building blocks for such architectures since they can precisely control optical diffraction. However, they are traditionally limited in their nonlinear and reconfigurable responses owing to their relatively low-quality factor (Q-factor). Here, we highlight new and emerging design strategies to increase the Q-factor while maintaining control of optical diffraction, enabling unprecedented spatial and temporal control of light. We describe how multipolar modes and bound states in the continuum increase Q and show how these high-Q nanoantennas can be cascaded to create almost limitless resonant optical transfer functions. With high-Q nanoantennas, new paradigms in reconfigurable wavefront-shaping, low-noise, multiplexed biosensors and quantum transduction are possible.

In the version of this article initially published, affiliation 38 incorrectly read “ICNU-Nephrology and Urology Department, Barcelona, Spain”; “Renal Division, Hospital Clinic, IDIBAPS, University of Barcelona, Barcelona, Spain” is the correct affiliation. The error has been corrected in the HTML and PDF versions of the article.

Background Cystic Fibrosis (CF) is the most common life threatening autosomal recessive multisystem disease in the Republic of Ireland (ROI); with a previously quoted incidence of 1 in 1353 and carrier rate of 1 in 19. Screening for CF was incorporated in the National new born screening (NBS) programme in July 2011 in the ROI. The benefit of early diagnosis is well documented. The purpose of the screening is to identify classic CF cases to allow early diagnosis and intervention and improve prognosis. A cut off point of the top 1% Immunoreactive Trypsinogen (IRT) was taken as an indication for 38 mutation panel molecular screening in the ROI National screening programme to maximise identification of affected typical CF cases and to minimise detection of carriers. Methods All neonates from July 2011 to Dec 2017 who had an elevated IRT on NBS were tested with 38 CFTR gene mutation panel and included in this study. Data from clinical and laboratory database were analysed and cross-referenced with patient charts. The Non-NBS database was used to track down cascade relatives. Results In the first 6 and a half years a total of 5,094 newborns (1.16% of total births in the period) were screened for CFTR mutation. During this period, 170 CF affected cases, 22 CFSPID (CF screening positive, Inconclusive diagnosis) and 325 healthy carriers were identified. Phe508del was the most common mutation (75%) followed by Gly551Asp (9.4%). 95 (56%) were homozygous for Phe508del, 17 (10%) were compound heterozygous for Phe508del and Gly551Asp and 22 (13%) were compound heterozygous for Gly551Asp. Hence, 69% of identified as an affected new-borns are eligible to use orphan drugs. There was one missed diagnosis. Conclusion The National new-born screening programme has been successful with only 1 missed diagnosis and less than 50% of carriers identified than predicted. We identified twice the number of affected new-born carrying the Gly551Asp mutation than previously quoted figures from elsewhere in Western Europe. As these are eligible for new orphan drugs this is important for drug reimbursement nationally. The revised incidence of CF in the ROI is less than previous reports (likely due to net immigration). We estimate the new revised incidence to be 1 in 2570 and the carrier frequency is 1 in 25.

Multi-gene testing is useful in genetically heterogeneous conditions, including inherited cardiac pathologies. Increasing the number of genes analysed increases diagnostic yield of variants of certain, likely, or uncertain pathogenicity. Concerns exist regarding management of variants of uncertain/likely pathogenicity in conditions of oligogenic inheritance or variable expressivity. We surveyed a sample of colleagues across different specialties and departments internationally to compare management of patients with class 3 or class 4 variants in genes associated with non-syndromic cardiomyopathy or arrhythmia. An electronic survey regarding clinical management of variants ( www.surveymonkey.com/r/cardiacvariants ) was designed and distributed to colleagues internationally via professional bodies and direct email. 150 respondents (88 centres, 27 countries) completed the survey, most of whom were Clinical Geneticists or Genetic Counsellors. Most respondents offer pre-symptomatic testing to asymptomatic relatives of an individual with class 4 or class 5 variants. A minority of respondents offer pre-symptomatic testing for class 3 variants. Considering class 4 variants, 22 (15%) are fully reassuring that the patient with a negative predictive test would not develop the familial phenotype, while 123 (82%) counselled patients about the possibility of variant reclassification. Variability existed between and within centres and specialties. Multiple "free text" comments were provided. Recurring themes including need for multidisciplinary input, technical concerns, and concern regarding duty to review variants of uncertain significance. This study demonstrates that variability in management of likely pathogenic/uncertain variants exists. Close multi-disciplinary input is essential. The development of disorder or gene-specific evidence-based guidelines might ameliorate uncertainty in management.