The growth in the capacity of electric power system creates a demand for the protection of relaying systems. Optical current transducers—OCT that are mainly made up of single mode optical fibers which are subjected t...The growth in the capacity of electric power system creates a demand for the protection of relaying systems. Optical current transducers—OCT that are mainly made up of single mode optical fibers which are subjected to Faraday rotation are used as a replacement for electromagnetic transducers due to their immunity to electromagnetic interference. However, the principal parameter in this system, the sensitivity to magnetic fields or current, depends on the Verdet constant, which is low in the case of optical fibers. However, the optical path length can be increased to compensate for it by winding the fiber around a current carrying element a large number of turns. In this work, we study a current sensor, which is made up of a conductor coil with a fiber inside, thus increasing sensitivity. We study the effect of the inhomogeneity of the magnetic field induced by the current on the sensitivity of the optical fiber sensor.展开更多
The paper demonstrated the feasibility of Lorentz Force Velocimetry for flow rate measurements of weakly conducting electrolytes using experimental results on salt water flow exposed to a permanent magnet system.This ...The paper demonstrated the feasibility of Lorentz Force Velocimetry for flow rate measurements of weakly conducting electrolytes using experimental results on salt water flow exposed to a permanent magnet system.This innovative flow measurement technique allows the non-contact determination of flow rates and relies on the interaction between a magnetic field and a moving conducting fluid.When an electrically conducting fluid moves through the magnetic field a Lorentz force is generated and acts on the measurement system.The present report provides an overview about the experimental setups and the first measurement results.展开更多
In the aerospace field,for aerospace engines and other high-end manufacturing equipment working in extreme environments,like ultrahigh temperatures,high pressure,and high-speed airflow,in situ temperature measurement ...In the aerospace field,for aerospace engines and other high-end manufacturing equipment working in extreme environments,like ultrahigh temperatures,high pressure,and high-speed airflow,in situ temperature measurement is of great importance for improving the structure design and achieving the health monitoring and the fault diagnosis of critical parts.Optical fiber sensors have the advantages of small size,easy design,corrosion resistance,anti-electromagnetic interference,and the ability to achieve distributed or quasi-distributed sensing and have broad application prospects for temperature sensing in extreme environments.In this review,first,we introduce the current research status of fiber Bragg grating-type and Fabry–Perot interferometer-type high-temperature sensors.Then we review the optical fiber hightemperature sensor encapsulation techniques,including tubular encapsulation,substrate encapsulation,and metalembedded encapsulation,and discuss the extreme environmental adaptability of different encapsulation structures.Finally,the critical technological issues that need to be solved for the application of optical fiber sensors in extreme environments are discussed.展开更多
This paper describes a standing-wave interferometer with two laser sources of different wavelengths,diametrically opposed and emitting towards each other.The resulting standing wave has an intensity profile which is m...This paper describes a standing-wave interferometer with two laser sources of different wavelengths,diametrically opposed and emitting towards each other.The resulting standing wave has an intensity profile which is moving with a constant velocity,and is directly detected inside the laser beam by two thin and transparent photo sensors.The first sensor is at a fixed position,serving as a phase reference for the second one which is moved along the optical axis,resulting in a frequency shift,proportional to the velocity.The phase difference between both sensors is evaluated for the purpose of interferometric length measurements.展开更多
Since the first realization of two-photon direct laser writing(DLW)in Maruo et al.(Opt Lett 22:132-134,1997),the manufacturing using direct laser writing techniques spread out in many laboratories all over the world.P...Since the first realization of two-photon direct laser writing(DLW)in Maruo et al.(Opt Lett 22:132-134,1997),the manufacturing using direct laser writing techniques spread out in many laboratories all over the world.Photosensitive materials with different material properties open a new field for micro-and nanofabrication.The achievable structuring resolution using this technique is reported to be sub-100 nm(Paz et al.in J.Laser Appl.24:042004,2012),while a smallest linewidth of 25 nm could be shown in Tan et al.(Appl Phys Lett 90:071106,2007).In our approach,the combination of DLW with the nanopositioning and nanomeasuring machine NMM-1 offers an improvement of the technique from the engineering side regarding the ultra-precise positioning(Weidenfeller et al.in Adv Fabr Technol Micro/Nano Opt Photon Ⅺ 10544:105440E,2018).One big benefit besides the high positioning resolution of 0.1 nm is offered by the positioning range of 25 mm×25 mm×5 mm(Jager et al.in Technisches Messen 67:319-323,2000;Manske et al.in Meas Sci Technol 18:520-527,2007).Thus,a trans-scale fabrication without any stitching or combination of different positioning systems is necessary.The immense synergy between the highly precise positioning and the DLW is demonstrated by the realization of resist lines and trenches whose center-to-center distance undergoes the modified diffraction limit for two-photon processes.The precise positioning accuracy enables a defined distance between illuminated lines.Hence,with a comparable huge width of the trenches of 1.655|im due to a low effective numerical aperture of 0.16,a resist line of 30 nm between two written trenches could be achieved.Although the interrelationships for achieving such narrow trenches have not yet been clarified,much smaller resist lines and trench widths are possible with this approach in the near future.展开更多
The majority of nanopositioning and nanomeasuring machines(NPMMs)are based on three independent linear movements in a Cartesian coordinate system.This in combination with the specific nature of sensors and tools limit...The majority of nanopositioning and nanomeasuring machines(NPMMs)are based on three independent linear movements in a Cartesian coordinate system.This in combination with the specific nature of sensors and tools limits the addressable part geometries.An enhancement of an NPMM is introduced by the implementation of rotational movements while keeping the precision in the nanometer range.For this purpose,a parameter-based dynamic evaluation system with quantifiable technological parameters has been set up and employed to identify and assess general solution concepts and adequate substructures.Evaluations taken show high potential for three linear movements of the object in combination with two angular movements of the tool.The influence of the additional rotation systems on the existing structure of NPMMs has been investigated further on.Test series on the repeatability of an NPMM enhanced by a chosen combination of a rotary stage and a goniometer setup are realized.As a result of these test series,the necessity of in situ position determination of the tool became very clear.The tool position is measured in situ in relation to a hemispherical reference mirror by three Fabry-Perot interferometers.FEA optimization has been used to enhance the overall system structure with regard to reproducibility and long-term stability.Results have been experimentally investigated by use of a retroreflector as a tool and the various laser interferometers of the NPMM.The knowledge gained has been formed into general rules for the verification and optimization of design solutions for multiaxial nanopositioning machines.展开更多
The field of optical lithography is subject to intense research and has gained enormous improvement.However,the effort necessary for creating structures at the size of 20 nm and below is considerable using conventiona...The field of optical lithography is subject to intense research and has gained enormous improvement.However,the effort necessary for creating structures at the size of 20 nm and below is considerable using conventional technologies.This effort and the resulting financial requirements can only be tackled by few global companies and thus a paradigm change for the semiconductor industry is conceivable:custom design and solutions for specific applications will dominate future development(Fritze in:Panning EM,Liddle JA(eds)Novel patterning technologies.International society for optics and photonics.SPIE,Bellingham,2021.https://doi.org/10.1117/12.2593229).For this reason,new aspects arise for future lithography,which is why enormous effort has been directed to the development of alternative fabrication technologies.Yet,the technologies emerging from this process,which are promising for coping with the current resolution and accuracy challenges,are only demonstrated as a proof-of-concept on a lab scale of several square micrometers.Such scale is not adequate for the requirements of modern lithography;therefore,there is the need for new and alternative cross-scale solutions to further advance the possibilities of unconventional nanotechnologies.Similar challenges arise because of the technical progress in various other fields,realizing new and unique functionalities based on nanoscale effects,e.g.,in nanophotonics,quantum computing,energy harvesting,and life sciences.Experimental platforms for basic research in the field of scale-spanning nanomeasuring and nanofabrication are necessary for these tasks,which are available at the Technische Universitiit Ilmenau in the form of nanopositioning and nanomeasuring(NPM)machines.With this equipment,the limits of technical structurability are explored for high-performance tip-based and laser-based processes for enabling real 3D nanofabrication with the highest precision in an adequate working range of several thousand cubic millimeters.展开更多
Nanomeasuring machines developed at the Technische Universitat Ilmenau enable three-dimensional measurements and manufacturing processes with the lowest uncertainties.Due to the requirements for these processes,a high...Nanomeasuring machines developed at the Technische Universitat Ilmenau enable three-dimensional measurements and manufacturing processes with the lowest uncertainties.Due to the requirements for these processes,a highly reproducible and long-term stable tool changing system is needed.For this purpose,kinematically determined couplings are widely used.The state-of-the-art investigations on those are not sufficient for the highest demands on the reproducibility required for this application.A theoretical determination of the reproducibility based on analytical or numerical methods is possible,however not in the desired nanometer range.Due to this,a measurement setup for the determination of the reproducibility in five degrees of freedom with nanometer uncertainty was developed.First,potential measuring devices are systematically examined and measurement principles were developed out of this.A three-dimensional vector-based uncertainty analysis is performed to prove the feasibility of the measurement principle and provides a basis for further design.As a result,a transla-tory measurement uncertainty of 10 nm and a rotatory uncertainty of 11 nrad can be reached.Afterwards,the measurement setup is designed,focusing on the metrological frame and the lift-off device.The developed setup exceeds the uncertainties of the measurement setups presented in the state-of-the-art by an order of magnitude,allowing new in-depth investigations of the reproducibility of kinematic couplings.展开更多
文摘The growth in the capacity of electric power system creates a demand for the protection of relaying systems. Optical current transducers—OCT that are mainly made up of single mode optical fibers which are subjected to Faraday rotation are used as a replacement for electromagnetic transducers due to their immunity to electromagnetic interference. However, the principal parameter in this system, the sensitivity to magnetic fields or current, depends on the Verdet constant, which is low in the case of optical fibers. However, the optical path length can be increased to compensate for it by winding the fiber around a current carrying element a large number of turns. In this work, we study a current sensor, which is made up of a conductor coil with a fiber inside, thus increasing sensitivity. We study the effect of the inhomogeneity of the magnetic field induced by the current on the sensitivity of the optical fiber sensor.
基金Item Sponsored by German Science Foundation (Deutsche Forschungsgemeinschaft) in the framework of theResearch Training Group (Graduiertenkolleg) "Lorentz Force Velocimetry and Lorentz Force Eddy Current Testing"(GRK 1567/1)at Ilmenau University of Technology
文摘The paper demonstrated the feasibility of Lorentz Force Velocimetry for flow rate measurements of weakly conducting electrolytes using experimental results on salt water flow exposed to a permanent magnet system.This innovative flow measurement technique allows the non-contact determination of flow rates and relies on the interaction between a magnetic field and a moving conducting fluid.When an electrically conducting fluid moves through the magnetic field a Lorentz force is generated and acts on the measurement system.The present report provides an overview about the experimental setups and the first measurement results.
基金supported by the National Natural Science Foundation of China(No.62275269)National Key Research and Development Program of China(No.2022YFF0706005)+3 种基金China Guangdong Guangxi Joint Science Key Foundation(No.2021GXNSFDA076001)Guangxi Major Projects of ScienceandTechnology(No.2020AA21077007)Interdisciplinary Scientific Research Foundation of Guangxi University(No.2022JCC014)China Scholarship Council(No.201903170207)。
文摘In the aerospace field,for aerospace engines and other high-end manufacturing equipment working in extreme environments,like ultrahigh temperatures,high pressure,and high-speed airflow,in situ temperature measurement is of great importance for improving the structure design and achieving the health monitoring and the fault diagnosis of critical parts.Optical fiber sensors have the advantages of small size,easy design,corrosion resistance,anti-electromagnetic interference,and the ability to achieve distributed or quasi-distributed sensing and have broad application prospects for temperature sensing in extreme environments.In this review,first,we introduce the current research status of fiber Bragg grating-type and Fabry–Perot interferometer-type high-temperature sensors.Then we review the optical fiber hightemperature sensor encapsulation techniques,including tubular encapsulation,substrate encapsulation,and metalembedded encapsulation,and discuss the extreme environmental adaptability of different encapsulation structures.Finally,the critical technological issues that need to be solved for the application of optical fiber sensors in extreme environments are discussed.
基金funded by the German Federal Ministry of Education and Research under contract 03V0235.
文摘This paper describes a standing-wave interferometer with two laser sources of different wavelengths,diametrically opposed and emitting towards each other.The resulting standing wave has an intensity profile which is moving with a constant velocity,and is directly detected inside the laser beam by two thin and transparent photo sensors.The first sensor is at a fixed position,serving as a phase reference for the second one which is moved along the optical axis,resulting in a frequency shift,proportional to the velocity.The phase difference between both sensors is evaluated for the purpose of interferometric length measurements.
基金the support by the Deutsche Forschungsgemeinschaft(DFG)in the framework of Research Training Group Tip-and laser-based 3D-Nanofcibrication in extended macroscopic working areas(GRK 2182)at the Technische Universitat Ilmenau,Germanyfinancial support from the DFG from the grant RE3012/4-1.
文摘Since the first realization of two-photon direct laser writing(DLW)in Maruo et al.(Opt Lett 22:132-134,1997),the manufacturing using direct laser writing techniques spread out in many laboratories all over the world.Photosensitive materials with different material properties open a new field for micro-and nanofabrication.The achievable structuring resolution using this technique is reported to be sub-100 nm(Paz et al.in J.Laser Appl.24:042004,2012),while a smallest linewidth of 25 nm could be shown in Tan et al.(Appl Phys Lett 90:071106,2007).In our approach,the combination of DLW with the nanopositioning and nanomeasuring machine NMM-1 offers an improvement of the technique from the engineering side regarding the ultra-precise positioning(Weidenfeller et al.in Adv Fabr Technol Micro/Nano Opt Photon Ⅺ 10544:105440E,2018).One big benefit besides the high positioning resolution of 0.1 nm is offered by the positioning range of 25 mm×25 mm×5 mm(Jager et al.in Technisches Messen 67:319-323,2000;Manske et al.in Meas Sci Technol 18:520-527,2007).Thus,a trans-scale fabrication without any stitching or combination of different positioning systems is necessary.The immense synergy between the highly precise positioning and the DLW is demonstrated by the realization of resist lines and trenches whose center-to-center distance undergoes the modified diffraction limit for two-photon processes.The precise positioning accuracy enables a defined distance between illuminated lines.Hence,with a comparable huge width of the trenches of 1.655|im due to a low effective numerical aperture of 0.16,a resist line of 30 nm between two written trenches could be achieved.Although the interrelationships for achieving such narrow trenches have not yet been clarified,much smaller resist lines and trench widths are possible with this approach in the near future.
基金the support of the Deutsche Forschungsgemeinschaft(DFG)in the framework of Research Training Group“Tip-and laser-based 3D-nanofabrication in extended macroscopic working areas”(GRK 2182)at the Technische Universitat Ilmenau,Germany。
文摘The majority of nanopositioning and nanomeasuring machines(NPMMs)are based on three independent linear movements in a Cartesian coordinate system.This in combination with the specific nature of sensors and tools limits the addressable part geometries.An enhancement of an NPMM is introduced by the implementation of rotational movements while keeping the precision in the nanometer range.For this purpose,a parameter-based dynamic evaluation system with quantifiable technological parameters has been set up and employed to identify and assess general solution concepts and adequate substructures.Evaluations taken show high potential for three linear movements of the object in combination with two angular movements of the tool.The influence of the additional rotation systems on the existing structure of NPMMs has been investigated further on.Test series on the repeatability of an NPMM enhanced by a chosen combination of a rotary stage and a goniometer setup are realized.As a result of these test series,the necessity of in situ position determination of the tool became very clear.The tool position is measured in situ in relation to a hemispherical reference mirror by three Fabry-Perot interferometers.FEA optimization has been used to enhance the overall system structure with regard to reproducibility and long-term stability.Results have been experimentally investigated by use of a retroreflector as a tool and the various laser interferometers of the NPMM.The knowledge gained has been formed into general rules for the verification and optimization of design solutions for multiaxial nanopositioning machines.
基金supported by the Deutsche Forschungsgemeinschaft(DFG)in the framework of the Research Training Group Tip-and Laser-based 3D-Nanofabrication in extended macroscopic working areas(GRK 2182)at the Technische Universitat Ilmenau,Germany.
文摘The field of optical lithography is subject to intense research and has gained enormous improvement.However,the effort necessary for creating structures at the size of 20 nm and below is considerable using conventional technologies.This effort and the resulting financial requirements can only be tackled by few global companies and thus a paradigm change for the semiconductor industry is conceivable:custom design and solutions for specific applications will dominate future development(Fritze in:Panning EM,Liddle JA(eds)Novel patterning technologies.International society for optics and photonics.SPIE,Bellingham,2021.https://doi.org/10.1117/12.2593229).For this reason,new aspects arise for future lithography,which is why enormous effort has been directed to the development of alternative fabrication technologies.Yet,the technologies emerging from this process,which are promising for coping with the current resolution and accuracy challenges,are only demonstrated as a proof-of-concept on a lab scale of several square micrometers.Such scale is not adequate for the requirements of modern lithography;therefore,there is the need for new and alternative cross-scale solutions to further advance the possibilities of unconventional nanotechnologies.Similar challenges arise because of the technical progress in various other fields,realizing new and unique functionalities based on nanoscale effects,e.g.,in nanophotonics,quantum computing,energy harvesting,and life sciences.Experimental platforms for basic research in the field of scale-spanning nanomeasuring and nanofabrication are necessary for these tasks,which are available at the Technische Universitiit Ilmenau in the form of nanopositioning and nanomeasuring(NPM)machines.With this equipment,the limits of technical structurability are explored for high-performance tip-based and laser-based processes for enabling real 3D nanofabrication with the highest precision in an adequate working range of several thousand cubic millimeters.
基金the support by the Deutsche Forschungsgemeinschaft(DFG)in the framework of Research Training Group"Tip-and laser-based 3D-Nanofabrication inextended macroscopic working areas"(GRK 2182)at the Technische Universiat Ilmenau,Germany.
文摘Nanomeasuring machines developed at the Technische Universitat Ilmenau enable three-dimensional measurements and manufacturing processes with the lowest uncertainties.Due to the requirements for these processes,a highly reproducible and long-term stable tool changing system is needed.For this purpose,kinematically determined couplings are widely used.The state-of-the-art investigations on those are not sufficient for the highest demands on the reproducibility required for this application.A theoretical determination of the reproducibility based on analytical or numerical methods is possible,however not in the desired nanometer range.Due to this,a measurement setup for the determination of the reproducibility in five degrees of freedom with nanometer uncertainty was developed.First,potential measuring devices are systematically examined and measurement principles were developed out of this.A three-dimensional vector-based uncertainty analysis is performed to prove the feasibility of the measurement principle and provides a basis for further design.As a result,a transla-tory measurement uncertainty of 10 nm and a rotatory uncertainty of 11 nrad can be reached.Afterwards,the measurement setup is designed,focusing on the metrological frame and the lift-off device.The developed setup exceeds the uncertainties of the measurement setups presented in the state-of-the-art by an order of magnitude,allowing new in-depth investigations of the reproducibility of kinematic couplings.
