An automatic system for marine meiobenthos separation was developed by using laser-induced fluorescence tech- nology. Rose Bengal was used as organism dye and the spectrums of Rose Bengal were measured. Laser-induced ...An automatic system for marine meiobenthos separation was developed by using laser-induced fluorescence tech- nology. Rose Bengal was used as organism dye and the spectrums of Rose Bengal were measured. Laser-induced fluorescence system was established to detect marine meiobenthos in sediments. Data obtained from experiments were analyzed by using a mathematical model. The results showed that laser-induced fluorescence technology worked well in the system. The system could select the meiobenthos efficiently and precisely.展开更多
A photoelectric equipment for inspecting artillery bore is composed of digital display grating sensor and data processing with computer.It can replace the traditional mechanical measurer and realize the automatic insp...A photoelectric equipment for inspecting artillery bore is composed of digital display grating sensor and data processing with computer.It can replace the traditional mechanical measurer and realize the automatic inspection of artillery bore.Introduced are briefly the working principles and analysis of this device.展开更多
Today, automated robot welding of components with low tolerances in series production is state-of-the-art. But turning to small batch production particularly of parts with high tolerances, engineering and construction...Today, automated robot welding of components with low tolerances in series production is state-of-the-art. But turning to small batch production particularly of parts with high tolerances, engineering and construction of automated solutions is just at the beginning of providing economic efficiency. While weld seam tracking is well established for the described problem, geometric recognition of weldments is not yet solved satisfactorily. This paper will present an optimisation approach of a laser sensor guided and programmed robot welding system which was developed within the project ROPROF at the TU Dortmund. With this development, a working prototype of a robot weld system was built by a steel construction company as well as additional demonstration software showing the potential and transferability of adjusted geometric location of weldments for industrial applications.展开更多
The distributed sensor is proven to be a powerful tool for civil structural and material process monitoring. Brillouin scattering in fiber can be used as point sensors or distributed sensors for measurement of tempera...The distributed sensor is proven to be a powerful tool for civil structural and material process monitoring. Brillouin scattering in fiber can be used as point sensors or distributed sensors for measurement of temperature, strain, birefringence and vibration over centimeters （Brillouin grating length） for point sensor or the pulse length for the distributed sensor. Simultaneous strain and temperature measurement with a spatial resolution of 20 cm is demonstrated in a Panda fiber using Brillouin grating technique with the temperature accuracy and strain accuracy of 0.4 ℃ and 9 με. This technique can also be used for distributed birefringence measurement. For Brillouin optical time domain analysis （BOTDA）, we have developed a new technique to measure differential Brillouin gain instead of Brillouin gain itself. This technique allows high precision temperature and strain measurement over long sensing length with sub-meter spatial resolution： 50-cm spatial resolution for 50-km length, using return-to-zero coded optical pulses of BOTDA with the temperature resolution of 0.7 ℃, which is equivalent to strain accuracy of 12 με. For over 50-km sensing length, we proposed and demonstrated frequency-division-multiplexing （FDM） and time-division-multiplexing （TDM） based BOTDA technique for 75-km and 100-km sensing length without inline amplification within the sensing length. The spatial resolution of 2m （100km） and Brillouin frequency shift accuracy of 1.5 MHz have been obtained for TDM based BOTDA and 1-m resolution （75 km） with Brillouin frequency shift accuracy of 1 MHz using FDM based BOTDA. The civil structural health monitoring with BOTDA technique has been demonstrated.展开更多
A new class of all-fiber beam shaping devices has been realized by inverse etching the end face of single mode and multimode fibers to form a concave cone tip. Concave tip fiber can convert a Gaussian beam profile to ...A new class of all-fiber beam shaping devices has been realized by inverse etching the end face of single mode and multimode fibers to form a concave cone tip. Concave tip fiber can convert a Gaussian beam profile to a flat top beam profile with a uniform intensity distribution. A flat top beam with intensity variation of approx. 5% and flat top diameter to spot diameter ratio of 67% has been achieved. This device can also change the beam shape from a Gaussian to a donut by moving the observation plane. A flat top multimode fiber beam delivery is attractive for applications which require high power and uniform intensity distribution. In single mode fiber, concave tips could be used to reduce the beam spot size diameter, enabling efficient light coupling from a single mode fiber to an integrated optical waveguide.展开更多
In this work the authors first summarily describe the main topics that were the subject of their post-graduate activity in fiber sensing at the Applied Optics Group of University of Kent in the late 1980s and early 19...In this work the authors first summarily describe the main topics that were the subject of their post-graduate activity in fiber sensing at the Applied Optics Group of University of Kent in the late 1980s and early 1990s. After their return to Porto, Portugal, the know-how acquired during their stay at Kent and the collaboration paths that followed between the University of Porto and University of Kent were instrumental in the start-up and progress of optical fiber sensing activity in Portugal. The main topics addressed in this field, the description of some of the relevant developments achieved in recent years, the present situation and the guidelines for the future research and development activity in Portugal in fiber sensing will be the core of this work.展开更多
In this paper I describe research activities in the field of optical fiber sensing undertaken by me after leaving the Applied Optics Group at the University of Kent. The main topics covered are long period gratings, n...In this paper I describe research activities in the field of optical fiber sensing undertaken by me after leaving the Applied Optics Group at the University of Kent. The main topics covered are long period gratings, neural network based signal processing, plasmonic sensors, and polymer fiber gratings. Ⅰ also give a summary of my two periods of research at the University of Kent, covering 1985-1988 and 1991-2001.展开更多
This paper summarizes research activities at University of Kent over the period from September 1981 through November 1984. Subsequent researches undertaken in the US Naval Research Laboratory and two start-up companie...This paper summarizes research activities at University of Kent over the period from September 1981 through November 1984. Subsequent researches undertaken in the US Naval Research Laboratory and two start-up companies are also described.展开更多
A review is presented of several technical solutions developed by the Applied Optics Group （AOG） in the field of low coherence interferometry applied to optical fiber sensors （OFS） that subsequently allowed AOG to...A review is presented of several technical solutions developed by the Applied Optics Group （AOG） in the field of low coherence interferometry applied to optical fiber sensors （OFS） that subsequently allowed AOG to quickly progress in the field of optical coherence tomography （OCT）.展开更多
基金Project (Grant No. DY105-03-01-15) supported by "Tenth FiveYear Plan of R & D of International Deep-Sea" of National OceanMineral Resources R & D Association, China
文摘An automatic system for marine meiobenthos separation was developed by using laser-induced fluorescence tech- nology. Rose Bengal was used as organism dye and the spectrums of Rose Bengal were measured. Laser-induced fluorescence system was established to detect marine meiobenthos in sediments. Data obtained from experiments were analyzed by using a mathematical model. The results showed that laser-induced fluorescence technology worked well in the system. The system could select the meiobenthos efficiently and precisely.
文摘A photoelectric equipment for inspecting artillery bore is composed of digital display grating sensor and data processing with computer.It can replace the traditional mechanical measurer and realize the automatic inspection of artillery bore.Introduced are briefly the working principles and analysis of this device.
文摘Today, automated robot welding of components with low tolerances in series production is state-of-the-art. But turning to small batch production particularly of parts with high tolerances, engineering and construction of automated solutions is just at the beginning of providing economic efficiency. While weld seam tracking is well established for the described problem, geometric recognition of weldments is not yet solved satisfactorily. This paper will present an optimisation approach of a laser sensor guided and programmed robot welding system which was developed within the project ROPROF at the TU Dortmund. With this development, a working prototype of a robot weld system was built by a steel construction company as well as additional demonstration software showing the potential and transferability of adjusted geometric location of weldments for industrial applications.
文摘The distributed sensor is proven to be a powerful tool for civil structural and material process monitoring. Brillouin scattering in fiber can be used as point sensors or distributed sensors for measurement of temperature, strain, birefringence and vibration over centimeters （Brillouin grating length） for point sensor or the pulse length for the distributed sensor. Simultaneous strain and temperature measurement with a spatial resolution of 20 cm is demonstrated in a Panda fiber using Brillouin grating technique with the temperature accuracy and strain accuracy of 0.4 ℃ and 9 με. This technique can also be used for distributed birefringence measurement. For Brillouin optical time domain analysis （BOTDA）, we have developed a new technique to measure differential Brillouin gain instead of Brillouin gain itself. This technique allows high precision temperature and strain measurement over long sensing length with sub-meter spatial resolution： 50-cm spatial resolution for 50-km length, using return-to-zero coded optical pulses of BOTDA with the temperature resolution of 0.7 ℃, which is equivalent to strain accuracy of 12 με. For over 50-km sensing length, we proposed and demonstrated frequency-division-multiplexing （FDM） and time-division-multiplexing （TDM） based BOTDA technique for 75-km and 100-km sensing length without inline amplification within the sensing length. The spatial resolution of 2m （100km） and Brillouin frequency shift accuracy of 1.5 MHz have been obtained for TDM based BOTDA and 1-m resolution （75 km） with Brillouin frequency shift accuracy of 1 MHz using FDM based BOTDA. The civil structural health monitoring with BOTDA technique has been demonstrated.
文摘A new class of all-fiber beam shaping devices has been realized by inverse etching the end face of single mode and multimode fibers to form a concave cone tip. Concave tip fiber can convert a Gaussian beam profile to a flat top beam profile with a uniform intensity distribution. A flat top beam with intensity variation of approx. 5% and flat top diameter to spot diameter ratio of 67% has been achieved. This device can also change the beam shape from a Gaussian to a donut by moving the observation plane. A flat top multimode fiber beam delivery is attractive for applications which require high power and uniform intensity distribution. In single mode fiber, concave tips could be used to reduce the beam spot size diameter, enabling efficient light coupling from a single mode fiber to an integrated optical waveguide.
文摘In this work the authors first summarily describe the main topics that were the subject of their post-graduate activity in fiber sensing at the Applied Optics Group of University of Kent in the late 1980s and early 1990s. After their return to Porto, Portugal, the know-how acquired during their stay at Kent and the collaboration paths that followed between the University of Porto and University of Kent were instrumental in the start-up and progress of optical fiber sensing activity in Portugal. The main topics addressed in this field, the description of some of the relevant developments achieved in recent years, the present situation and the guidelines for the future research and development activity in Portugal in fiber sensing will be the core of this work.
文摘In this paper I describe research activities in the field of optical fiber sensing undertaken by me after leaving the Applied Optics Group at the University of Kent. The main topics covered are long period gratings, neural network based signal processing, plasmonic sensors, and polymer fiber gratings. Ⅰ also give a summary of my two periods of research at the University of Kent, covering 1985-1988 and 1991-2001.
文摘This paper summarizes research activities at University of Kent over the period from September 1981 through November 1984. Subsequent researches undertaken in the US Naval Research Laboratory and two start-up companies are also described.
文摘A review is presented of several technical solutions developed by the Applied Optics Group （AOG） in the field of low coherence interferometry applied to optical fiber sensors （OFS） that subsequently allowed AOG to quickly progress in the field of optical coherence tomography （OCT）.
