The profiling of plasma cell-free DNA(cfDNA)is becoming a valuable tool rapidly for tumor diagnosis,monitoring and prognosis.Diverse plasma cfDNA technologies have been in routine or emerging use,including analyses of...The profiling of plasma cell-free DNA(cfDNA)is becoming a valuable tool rapidly for tumor diagnosis,monitoring and prognosis.Diverse plasma cfDNA technologies have been in routine or emerging use,including analyses of mutations,copy number alterations,gene fusions and DNA methylation.Recently,new technologies in cfDNA analysis have been developed in laboratories,and potentially reflect the status of epigenetic modification,the immune microenvironment and the microbiome in tumor tissues.In this review,the authors discuss the principles,methods and effects of the current cfDNA assays and provide an overview of studies that may inform clinical applications in the near future.展开更多
Gene expression patterns of tumor cells can be inferred from features of circulating cell-free DNA(cfDNA),such as histone modifications and fragmentation patterns at promoters.However,the direct relationship between c...Gene expression patterns of tumor cells can be inferred from features of circulating cell-free DNA(cfDNA),such as histone modifications and fragmentation patterns at promoters.However,the direct relationship between cfDNA patterns and tumor-specific chromatin accessibility has not yet been experimentally established,limiting its current application to cancer diagnosis alone.展开更多
High-speed polarization management is highly desirable for many applications,such as remote sensing,telecommunication,and medical diagnosis.However,most of the approaches for polarization management rely on bulky opti...High-speed polarization management is highly desirable for many applications,such as remote sensing,telecommunication,and medical diagnosis.However,most of the approaches for polarization management rely on bulky optical components that are slow to respond,cumbersome to use,and sometimes with high drive voltages.Here,we overcome these limitations by harnessing photonic integrated circuits based on thin-film lithium niobate platform.We successfully realize a portfolio of thin-film lithium niobate devices for essential polarization management functionalities,including arbitrary polarization generation,fast polarization measurement,polarization scrambling,and automatic polarization control.The present devices feature ultra-fast control speeds,low drive voltages,low optical losses and compact footprints.Using these devices,we achieve high fidelity polarization generation with a polarization extinction ratio up to 41.9 dB and fast polarization scrambling with a scrambling rate up to 65 Mrad s−1,both of which are best results in integrated optics.We also demonstrate the endless polarization state tracking operation in our devices.The demonstrated devices unlock a drastically new level of performance and scales in polarization management devices,leading to a paradigm shift in polarization management.展开更多
Integrated traveling-wave lithium niobate modulators need relatively large device lengths to achieve low drive voltage. To increase modulation efficiency within a compact footprint, we report an integrated Fabry–Pero...Integrated traveling-wave lithium niobate modulators need relatively large device lengths to achieve low drive voltage. To increase modulation efficiency within a compact footprint, we report an integrated Fabry–Perot-type electro-optic thin film lithium niobate on insulator modulator comprising a phase modulation region sandwiched between two distributed Bragg reflectors. The device exhibits low optical loss and a high tuning efficiency of 15.7 pm/V. We also confirm the modulator's high-speed modulation performance by non-return-to-zero modulation with a data rate up to 56 Gbit/s.展开更多
Optical modulators have been and will continue to be essential devices for energy-and cost-efficient optical communication networks.Heterogeneous silicon and lithium niobate modulators have demonstrated promising perf...Optical modulators have been and will continue to be essential devices for energy-and cost-efficient optical communication networks.Heterogeneous silicon and lithium niobate modulators have demonstrated promising performances of low optical loss,low drive voltage,and large modulation bandwidth.However,DC bias drift is a major drawback of optical modulators using lithium niobate as the active electro-optic material.Here,we demonstrate high-speed and bias-drift-free Mach–Zehnder modulators based on the heterogeneous silicon and lithium niobate platform.The devices combine stable thermo-optic DC biases in silicon and ultra-fast electro-optic modulation in lithium niobate,and exhibit a low insertion loss of 1.8 d B,a low half-wave voltage of 3 V,an electro-optic modulation bandwidth of at least 70 GHz,and modulation data rates up to 128 Gb/s.展开更多
A tunable optical delay line(ODL) featuring high switching speed and low optical loss is highly desirable in many fields. Here, based on the thin-film lithium niobate platform, we demonstrate a digitally tunable on-ch...A tunable optical delay line(ODL) featuring high switching speed and low optical loss is highly desirable in many fields. Here, based on the thin-film lithium niobate platform, we demonstrate a digitally tunable on-chip ODL that includes five Mach–Zehnder interferometer optical switches, four flip-chip photodetectors, and four delayline waveguides. The proposed optical switches can achieve a switching speed of 13 ns and an extinction ratio of34.9 dB. Using a modified Euler-bend-based spiral structure, the proposed delay-line waveguide can simultaneously achieve a small footprint and low optical propagation loss. The proposed ODL can provide a maximum delay time of 150 ps with a resolution of 10 ps and feature a maximum insertion loss of 3.4 dB.展开更多
基金supported by the Beijing Natural Science Foundation(No.Z190022)the National Natural Science Foundation of China(No.81972680,81773292 and 82072748)。
文摘The profiling of plasma cell-free DNA(cfDNA)is becoming a valuable tool rapidly for tumor diagnosis,monitoring and prognosis.Diverse plasma cfDNA technologies have been in routine or emerging use,including analyses of mutations,copy number alterations,gene fusions and DNA methylation.Recently,new technologies in cfDNA analysis have been developed in laboratories,and potentially reflect the status of epigenetic modification,the immune microenvironment and the microbiome in tumor tissues.In this review,the authors discuss the principles,methods and effects of the current cfDNA assays and provide an overview of studies that may inform clinical applications in the near future.
基金supported by Beijing Natural Science Foundation(Z190022)the National Natural Science Foundation of China(81972680,82141102,52271254,82072748,82141102,and 82072748)+3 种基金a start-up fund from Tsinghua University-Peking University Joined Center for Life Science,Guangxi One Thousand Young and Middle-Aged College and University Backone Teachers Cultivation Program,the CAMS Innovation Fund for Medical Sciences(2021-12M-1-002 and 2023-12M-2-002)the National High Level Hospital Clinical Research Funding(2022-PUMCH-D-001,2022-PUMCH-A-082)the National Key Research and Development Program of China(2020YFA0803702)the Science Foundation of Peking University Cancer Hospital(PY202330).
文摘Gene expression patterns of tumor cells can be inferred from features of circulating cell-free DNA(cfDNA),such as histone modifications and fragmentation patterns at promoters.However,the direct relationship between cfDNA patterns and tumor-specific chromatin accessibility has not yet been experimentally established,limiting its current application to cancer diagnosis alone.
基金supported by the National Key Research and Development Program of China(2019YFB1803900 and 2019YFA0705000)National Natural Science Foundation of China(11690031 and 11761131001)+2 种基金Key R&D Program of Guangdong Province(2018B030329001)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01X121)Key-Area Research and Development Program of Guangdong Province(2019B121204003).
文摘High-speed polarization management is highly desirable for many applications,such as remote sensing,telecommunication,and medical diagnosis.However,most of the approaches for polarization management rely on bulky optical components that are slow to respond,cumbersome to use,and sometimes with high drive voltages.Here,we overcome these limitations by harnessing photonic integrated circuits based on thin-film lithium niobate platform.We successfully realize a portfolio of thin-film lithium niobate devices for essential polarization management functionalities,including arbitrary polarization generation,fast polarization measurement,polarization scrambling,and automatic polarization control.The present devices feature ultra-fast control speeds,low drive voltages,low optical losses and compact footprints.Using these devices,we achieve high fidelity polarization generation with a polarization extinction ratio up to 41.9 dB and fast polarization scrambling with a scrambling rate up to 65 Mrad s−1,both of which are best results in integrated optics.We also demonstrate the endless polarization state tracking operation in our devices.The demonstrated devices unlock a drastically new level of performance and scales in polarization management devices,leading to a paradigm shift in polarization management.
基金partially supported by the National Key R&D Program of China(Nos.2019YFA0705000 and 2019YFB1803900)the National Natural Science Foundation of China(Nos.11690031 and 11761131001)+3 种基金the Key R&D Program of Guangdong Province(No.2018B030329001)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01X121)the Innovation Fund of WNLO(No.2018WNLOKF010)the Project of Key Laboratory of Radar Imaging and Microwave Photonics,Ministry of Education(No.RIMP2019003)。
文摘Integrated traveling-wave lithium niobate modulators need relatively large device lengths to achieve low drive voltage. To increase modulation efficiency within a compact footprint, we report an integrated Fabry–Perot-type electro-optic thin film lithium niobate on insulator modulator comprising a phase modulation region sandwiched between two distributed Bragg reflectors. The device exhibits low optical loss and a high tuning efficiency of 15.7 pm/V. We also confirm the modulator's high-speed modulation performance by non-return-to-zero modulation with a data rate up to 56 Gbit/s.
基金National Key Research and Development Program of China(2019YFB1803900)National Natural Science Foundation of China(11690031,11761131001)+6 种基金Guangzhou Science and Technology Program(201707010096)Key RD Program of Guangdong Province(2018B030329001)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01X121)Innovation Fund of WNLO(2018WNLOKF010)Key-Area Research and Development Program of Guangdong Province(2019B121204003)Project of Key Laboratory of Radar Imaging and Microwave Photonics,Ministry of Education(RIMP2019003)Opening funds from State Key Laboratory of Optoelectronic Materials and Technologies of China,Sun Yat-sen University(OEMT-2018-KF-04)。
文摘Optical modulators have been and will continue to be essential devices for energy-and cost-efficient optical communication networks.Heterogeneous silicon and lithium niobate modulators have demonstrated promising performances of low optical loss,low drive voltage,and large modulation bandwidth.However,DC bias drift is a major drawback of optical modulators using lithium niobate as the active electro-optic material.Here,we demonstrate high-speed and bias-drift-free Mach–Zehnder modulators based on the heterogeneous silicon and lithium niobate platform.The devices combine stable thermo-optic DC biases in silicon and ultra-fast electro-optic modulation in lithium niobate,and exhibit a low insertion loss of 1.8 d B,a low half-wave voltage of 3 V,an electro-optic modulation bandwidth of at least 70 GHz,and modulation data rates up to 128 Gb/s.
基金National Key Research and Development Program of China(2019YFA0705004,2019YFB1803901)Key R&D Program of Guangdong Province(2018B03032900)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01X121)。
文摘A tunable optical delay line(ODL) featuring high switching speed and low optical loss is highly desirable in many fields. Here, based on the thin-film lithium niobate platform, we demonstrate a digitally tunable on-chip ODL that includes five Mach–Zehnder interferometer optical switches, four flip-chip photodetectors, and four delayline waveguides. The proposed optical switches can achieve a switching speed of 13 ns and an extinction ratio of34.9 dB. Using a modified Euler-bend-based spiral structure, the proposed delay-line waveguide can simultaneously achieve a small footprint and low optical propagation loss. The proposed ODL can provide a maximum delay time of 150 ps with a resolution of 10 ps and feature a maximum insertion loss of 3.4 dB.
