Cryogenic crystal bolometer plays a crucial role in searching for neutrinoless double-beta(0νββ)decay,which is a rare process that could determine the Majorana nature of neutrinos.The flagship bolometer experiment...Cryogenic crystal bolometer plays a crucial role in searching for neutrinoless double-beta(0νββ)decay,which is a rare process that could determine the Majorana nature of neutrinos.The flagship bolometer experiment—CUORE(Cryogenic Underground Observatory for Rare Events)—operating at the Gran Sasso underground laboratory[Laboratori Nazionali del Gran Sasso(LNGS)]as the world’s first ton-scale bolometric detector has achieved great success and well demonstrated advantages of the bolometric technology for the 0νββ study.The proposed upgrade of CUORE—the CUPID project—aims to achieve higher sensitivity with orders of magnitude background reduction by utilizing scintillating crystals and dual readout technology to exclude most of the background events dominated by alpha particles.Although CUPID has outstanding advantages over CUORE,further increasing the detection capability to fully explore the effective neutrino mass region for the inverted neutrino mass hierarchy and possibly to discover Majorana neutrinos remains a technical challenge ahead.In this prospective,we discuss strategies toward future technology development to further enhance the experimental sensitivity.展开更多
Waveguide-integrated mid-infrared(MIR)photodetectors are pivotal components for the development of molecular spectroscopy applications,leveraging mature photonic integrated circuit(PIC)technologies.Despite various str...Waveguide-integrated mid-infrared(MIR)photodetectors are pivotal components for the development of molecular spectroscopy applications,leveraging mature photonic integrated circuit(PIC)technologies.Despite various strategies,critical challenges still remain in achieving broadband photoresponse,cooling-free operation,and large-scale complementary-metal-oxide-semiconductor(CMOS)-compatible manufacturability.To leap beyond these limitations,the bolometric effect–a thermal detection mechanism–is introduced into the waveguide platform.More importantly,we pursue a free-carrier absorption(FCA)process in germanium(Ge)to create an efficient light-absorbing medium,providing a pragmatic solution for full coverage of the MIR spectrum without incorporating exotic materials into CMOS.Here,we present an uncooled waveguide-integrated photodetector based on a Ge-on-insulator(Ge-OI)PIC architecture,which exploits the bolometric effect combined with FCA.Notably,our device exhibits a broadband responsivity of 28.35%/mW across 4030–4360 nm(and potentially beyond),challenging the state of the art,while achieving a noise-equivalent power of 4.03×10^(−7) W/Hz^(0.5) at 4180 nm.We further demonstrate label-free sensing of gaseous carbon dioxide(CO_(2))using our integrated photodetector and sensing waveguide on a single chip.This approach to room-temperature waveguide-integrated MIR photodetection,harnessing bolometry with FCA in Ge,not only facilitates the realization of fully integrated lab-on-a-chip systems with wavelength flexibility but also provides a blueprint for MIR PICs with CMOS-foundry-compatibility.展开更多
Bolometers are considered to be a standard diagnostic for fusion experiments, mainly for measuring the total radiated power and spatial profiles of the local radiation power density. New design and the first result ar...Bolometers are considered to be a standard diagnostic for fusion experiments, mainly for measuring the total radiated power and spatial profiles of the local radiation power density. New design and the first result are presented from three AXUV arrays with high temporal resolution installed on the HL-2A tokamak. This high temporal resolution allows the study of transient radiative phenomena.展开更多
The main characteristics of millimeter-wave(MM-wave)image detector were simulated by means of accurate numerical modeling of thermophysical processes in a metamaterial MM-to-IR converter.The converter represents a mul...The main characteristics of millimeter-wave(MM-wave)image detector were simulated by means of accurate numerical modeling of thermophysical processes in a metamaterial MM-to-IR converter.The converter represents a multilayer structure consisting of an ultra thin resonant metamaterial absorber and a perfect emissive layer.The absorber consists of a dielectric self-supporting film that is metallized from both sides.A micropattern is fabricated from one side.Resonant absorption of the MM waves induces the converter heating that yields enhancement of IR emission from the emissive layer.IR emission is detected by IR camera.In this contribution an accurate numerical model for simulation of the thermal processes in the converter structure was created by using COMSOL Multiphysics software.The simulation results are in a good agreement with experimental results that validates the model.The simulation shows that the real-time operation is provided for the converter thickness less than 3µm and time response can be improved by decreasing of the converter thickness.The energy conversion efficiency of MM waves into IR radiation is over 80%.The converter temperature increase is a linear function of a MM-wave radiation power within three orders of the dynamic range.The blooming effect and ways of its reducing are also discussed.The model allows us to choose the ways of converter structure optimization and improvement of image detector parameters.展开更多
基金supported in part by the State Key Research Development Program in China under grant no.2022YFA1604702.
文摘Cryogenic crystal bolometer plays a crucial role in searching for neutrinoless double-beta(0νββ)decay,which is a rare process that could determine the Majorana nature of neutrinos.The flagship bolometer experiment—CUORE(Cryogenic Underground Observatory for Rare Events)—operating at the Gran Sasso underground laboratory[Laboratori Nazionali del Gran Sasso(LNGS)]as the world’s first ton-scale bolometric detector has achieved great success and well demonstrated advantages of the bolometric technology for the 0νββ study.The proposed upgrade of CUORE—the CUPID project—aims to achieve higher sensitivity with orders of magnitude background reduction by utilizing scintillating crystals and dual readout technology to exclude most of the background events dominated by alpha particles.Although CUPID has outstanding advantages over CUORE,further increasing the detection capability to fully explore the effective neutrino mass region for the inverted neutrino mass hierarchy and possibly to discover Majorana neutrinos remains a technical challenge ahead.In this prospective,we discuss strategies toward future technology development to further enhance the experimental sensitivity.
基金supported by the National Research Foundation of Korea(NRF)(2023R1A2C2002777,RS-2024-00407767)the KIST Institutional Program(2E33052)the BK21 FOUR.
文摘Waveguide-integrated mid-infrared(MIR)photodetectors are pivotal components for the development of molecular spectroscopy applications,leveraging mature photonic integrated circuit(PIC)technologies.Despite various strategies,critical challenges still remain in achieving broadband photoresponse,cooling-free operation,and large-scale complementary-metal-oxide-semiconductor(CMOS)-compatible manufacturability.To leap beyond these limitations,the bolometric effect–a thermal detection mechanism–is introduced into the waveguide platform.More importantly,we pursue a free-carrier absorption(FCA)process in germanium(Ge)to create an efficient light-absorbing medium,providing a pragmatic solution for full coverage of the MIR spectrum without incorporating exotic materials into CMOS.Here,we present an uncooled waveguide-integrated photodetector based on a Ge-on-insulator(Ge-OI)PIC architecture,which exploits the bolometric effect combined with FCA.Notably,our device exhibits a broadband responsivity of 28.35%/mW across 4030–4360 nm(and potentially beyond),challenging the state of the art,while achieving a noise-equivalent power of 4.03×10^(−7) W/Hz^(0.5) at 4180 nm.We further demonstrate label-free sensing of gaseous carbon dioxide(CO_(2))using our integrated photodetector and sensing waveguide on a single chip.This approach to room-temperature waveguide-integrated MIR photodetection,harnessing bolometry with FCA in Ge,not only facilitates the realization of fully integrated lab-on-a-chip systems with wavelength flexibility but also provides a blueprint for MIR PICs with CMOS-foundry-compatibility.
文摘Bolometers are considered to be a standard diagnostic for fusion experiments, mainly for measuring the total radiated power and spatial profiles of the local radiation power density. New design and the first result are presented from three AXUV arrays with high temporal resolution installed on the HL-2A tokamak. This high temporal resolution allows the study of transient radiative phenomena.
文摘The main characteristics of millimeter-wave(MM-wave)image detector were simulated by means of accurate numerical modeling of thermophysical processes in a metamaterial MM-to-IR converter.The converter represents a multilayer structure consisting of an ultra thin resonant metamaterial absorber and a perfect emissive layer.The absorber consists of a dielectric self-supporting film that is metallized from both sides.A micropattern is fabricated from one side.Resonant absorption of the MM waves induces the converter heating that yields enhancement of IR emission from the emissive layer.IR emission is detected by IR camera.In this contribution an accurate numerical model for simulation of the thermal processes in the converter structure was created by using COMSOL Multiphysics software.The simulation results are in a good agreement with experimental results that validates the model.The simulation shows that the real-time operation is provided for the converter thickness less than 3µm and time response can be improved by decreasing of the converter thickness.The energy conversion efficiency of MM waves into IR radiation is over 80%.The converter temperature increase is a linear function of a MM-wave radiation power within three orders of the dynamic range.The blooming effect and ways of its reducing are also discussed.The model allows us to choose the ways of converter structure optimization and improvement of image detector parameters.
