Analysis of the generation of amplitude-squeezed light with Gaussian-beam degenerate optical parametric amplifiers

Cataloged from PDF version of article.We investigate the generation of amplitude-squeezed states with degenerate optical parametric amplifiers that are pumped by focused Gaussian beams. We present a model that facilitates the calculation of the squeezing level for an experimentally realistic cofiguration in which there is a Gaussian input signal beam that has the same confocal parameter and waist location as the Gaussian pump beam, with no restriction on the interaction length-to-confocal parameter ratio. We show that the 3-dB squeezing limit that was thought to be imposed by the Gaussian pump profile can be exceeded in the (previously uninvestigated) tight-focusing regime. We find the maximum possible amplitude squeezing in this regime to be 4.65 dB. However, it is possible to increase the squeezing level further by spatially filtering the tails of the output signal beam, resulting in squeezing levels in excess of 10 dB. (C) 2001 Optical Society of America

Phase matched self-doubling optical parametric oscillator

Cataloged from PDF version of article.We report a synchronously pumped intracavity frequency-doubled optical parametric oscillator that employs a single KTiOPO4 crystal for both parametric generation and frequency doubling. Both nonlinear processes are phase matched for the same direction of propagation in the crystal. The parametric oscillator, pumped by a femtosecond Ti:sapphire laser at a wavelength of 745 nm, generates a green output beam at 540 nm with a 29% power conversion efficiency. Angle tuning in conjunction with pump wavelength tuning provides output tunability in the 530–585-nm range. 1997 Optical Society of Americ

Single-crystal sum-frequency-generating optical parametric oscillator

Cataloged from PDF version of article.We report a synchronously pumped optical parametric oscillator that generates the sum frequency of the pump and the signal wavelengths. A single KTiOPO4 (KTP) crystal is used for both parametric generation and sum-frequency generation in which these two processes are simultaneously phase matched for the same direction of propagation. The parametric oscillator, pumped by a femtosecond Ti:sapphire laser at a wavelength of 827 nm, generates a blue output beam at 487 nm with 43% power-conversion efficiency. The polarization geometry of simultaneous phase matching requires rotation of the pump polarization before the cavity. Adjusting the group delay between the two orthogonally polarized pump components to compensate for the group-velocity mismatch in the KTP crystal increases the photon-conversion efficiency more than threefold. Angle tuning in conjunction with pump wavelength tuning provides output: tunability in the 484-512-nm range. A planewave model that takes group-velocity mismatch into account is in good agreement with our experimental results. (C) 1999 Optical Society of America [S0740-3224(99)01309-0]

Single-crystal sum-frequency generating optical parametric oscillator

A sum-frequency generating optical parametric oscillator (OPO), where a single crystal is employed for both parametric oscillation and sum frequency generation, is presented. The OPO is based on a KTiOPO4 crystal that is pumped by a Ti:sapphire laser operating at a wavelength of 828 nm. The two-step conversion is efficient, since both nonlinear conversion processes are phase matched in the same crystal

Phase-matched self-doubling optical parametric oscillator

A new self-doubling optical parametric oscillator (OPO) uses a single nonlinear crystal for both parametric generation and frequency doubling. It is based on a KTiOPO4 (KTP) crystal pumped by a Ti:Sapphire laser operating at a wavelength of 739 nm. The crystal is cut such that the signal wavelength of the OPO is at 1064 nm, corresponding to an idler wavelength of 2420 nm. The OPO cavity resonates only the signal wavelength. The signal beam is also phase-matched for second harmonic generation (SHG) at the same crystal orientation. With proper polarization rotation, an output beam at a wavelength of 532 nm can be obtained

Advances in femtosecond single-crystal sum-frequency generating optical parametric oscillators

The effect of compensating the group velocity mismatch between the orthogonal pump components on the conversion efficiency of the optical parametric oscillators (OPOs) was investigated. A femtosecond single-crystal sum-frequency generating optical parametric oscillators (OPO) based on a Ti:sapphire laser pumped KTiOPO4 crystal was used. presented. The crystal was phase matched for a specific signal wavelength corresponding to the operational wavelength of the laser. The crystal was also phase-matched for the sum-frequency generations (SFG) of the pump and the signal beams yielded a blue output beam. The conversion efficiency of the OPOs increased by compensating the group velocity mismatch

Synergistic insights into human health from aptamer- and antibody-based proteomic profiling

Affinity-based proteomics has enabled scalable quantification of thousands of protein targets in blood enhancing biomarker discovery, understanding of disease mechanisms, and genetic evaluation of drug targets in humans through protein quantitative trait loci (pQTLs). Here, we integrate two partly complementary techniques-the aptamer-based SomaScan® v4 assay and the antibody-based Olink assays-to systematically assess phenotypic consequences of hundreds of pQTLs discovered for 871 protein targets across both platforms. We create a genetically anchored cross-platform proteome-phenome network comprising 547 protein-phenotype connections, 36.3% of which were only seen with one of the two platforms suggesting that both techniques capture distinct aspects of protein biology. We further highlight discordance of genetically predicted effect directions between assays, such as for PILRA and Alzheimer's disease. Our results showcase the synergistic nature of these technologies to better understand and identify disease mechanisms and provide a benchmark for future cross-platform discoveries

Synergistic insights into human health from aptamer- and antibody-based proteomic profiling.

Funder: Wellcome TrustAffinity-based proteomics has enabled scalable quantification of thousands of protein targets in blood enhancing biomarker discovery, understanding of disease mechanisms, and genetic evaluation of drug targets in humans through protein quantitative trait loci (pQTLs). Here, we integrate two partly complementary techniques-the aptamer-based SomaScan® v4 assay and the antibody-based Olink assays-to systematically assess phenotypic consequences of hundreds of pQTLs discovered for 871 protein targets across both platforms. We create a genetically anchored cross-platform proteome-phenome network comprising 547 protein-phenotype connections, 36.3% of which were only seen with one of the two platforms suggesting that both techniques capture distinct aspects of protein biology. We further highlight discordance of genetically predicted effect directions between assays, such as for PILRA and Alzheimer's disease. Our results showcase the synergistic nature of these technologies to better understand and identify disease mechanisms and provide a benchmark for future cross-platform discoveries.The Fenland Study (10.22025/2017.10.101.00001) is funded by the Medical Research Council (MC_UU_12015/1). We are grateful to all the volunteers and to the General Practitioners and practice staff for assistance with recruitment. We thank the Fenland Study Investigators, Fenland Study Co-ordination team and the Epidemiology Field, Data and Laboratory teams. We further acknowledge support for genomics from the Medical Research Council (MC_PC_13046). Proteomic measurements were supported and governed by a collaboration agreement between the University of Cambridge and Somalogic. JCZ is supported by a 4-year Wellcome Trust PhD Studentship and the Cambridge Trust, CL, EW, and NJW are funded by the Medical Research Council (MC_UU_12015/1). NJW is a NIHR Senior Investigator. ADH is an NIHR Senior Investigator and supported by the UCL Hospitals NIHR Biomedical Research Centre and the UCL BHF Research Accelerator (AA/18/6/34223). We thank Philippa Pettingill, Ida Grundberg, Klev Diamanti, and Andrea Ballagi for advice and comments on an earlier draft of this manuscript. We thank Vladimir Saudek for generating a 3D-model of variant GDF-15 protein

GIGYF1 loss of function is associated with clonal mosaicism and adverse metabolic health.

Funder: Department of HealthMosaic loss of chromosome Y (LOY) in leukocytes is the most common form of clonal mosaicism, caused by dysregulation in cell-cycle and DNA damage response pathways. Previous genetic studies have focussed on identifying common variants associated with LOY, which we now extend to rarer, protein-coding variation using exome sequences from 82,277 male UK Biobank participants. We find that loss of function of two genes-CHEK2 and GIGYF1-reach exome-wide significance. Rare alleles in GIGYF1 have not previously been implicated in any complex trait, but here loss-of-function carriers exhibit six-fold higher susceptibility to LOY (OR = 5.99 [3.04-11.81], p = 1.3 × 10-10). These same alleles are also associated with adverse metabolic health, including higher susceptibility to Type 2 Diabetes (OR = 6.10 [3.51-10.61], p = 1.8 × 10-12), 4 kg higher fat mass (p = 1.3 × 10-4), 2.32 nmol/L lower serum IGF1 levels (p = 1.5 × 10-4) and 4.5 kg lower handgrip strength (p = 4.7 × 10-7) consistent with proposed GIGYF1 enhancement of insulin and IGF-1 receptor signalling. These associations are mirrored by a common variant nearby associated with the expression of GIGYF1. Our observations highlight a potential direct connection between clonal mosaicism and metabolic health