To achieve radar and infrared stealth, an infrared stealth layer is usually added to the radar absorbing material（RAM） of stealth aircraft. By analyzing the millimeter-wave（MMW） emissivities of three stealth mater...To achieve radar and infrared stealth, an infrared stealth layer is usually added to the radar absorbing material（RAM） of stealth aircraft. By analyzing the millimeter-wave（MMW） emissivities of three stealth materials, this Letter investigates the impact of the added infrared stealth layer on the originally ＂hot＂ MMW emission of RAM. The theoretical and measured results indicate that, compared with the monolayer RAM, the MMW emission of the bilayer material is still strong and its emissivity is reduced by 0.1–0.2 at almost every incident angle.The results partially demonstrate the feasibility of detecting stealth aircraft coated with this bilayer stealth material.展开更多
A magnetic field sensor with a magnetic fluid(MF)-coated intermodal interferometer is proposed and experimentally demonstrated. The interferometer is formed by sandwiching a segment of single mode fiber(SMF) between a...A magnetic field sensor with a magnetic fluid(MF)-coated intermodal interferometer is proposed and experimentally demonstrated. The interferometer is formed by sandwiching a segment of single mode fiber(SMF) between a segment of multi-mode fiber(MMF) and a spherical structure. It can be considered as a cascade of the traditional SMF-MMF-SMF structure and MMF-SMF-sphere structure. The transmission spectral characteristics change with the variation of applied magnetic field. The experimental results exhibit that the magnetic field sensitivities for wavelength and transmission loss are 0.047 nm/m T and 0.215 d B/m T for the interference dip around 1 535.36 nm. For the interference dip around 1548.41 nm,the sensitivities are 0.077 nm/m T and 0.243 d B/m T. Simultaneous measurement can be realized according to the different spectral responses.展开更多
A novel magnetic field sensor based on optical fiber Mach-Zehnder interferometer(MZI) coated by magnetic fluid(MF) is proposed. The MZI consists of two spherical structures formed on standard single mode fiber(SMF). T...A novel magnetic field sensor based on optical fiber Mach-Zehnder interferometer(MZI) coated by magnetic fluid(MF) is proposed. The MZI consists of two spherical structures formed on standard single mode fiber(SMF). The interference wavelength and the power of the sensing structure are sensitive to the external refractive index(RI). Since RI of the MF is sensitive to the magnetic field, the magnetic field measurement can be realized by detecting the variation of the interference spectrum. Experimental results show that the wavelength and the power of interference dip both increase with the increase of magnetic field intensity.展开更多
基金supported partially by the Shanghai Spaceflight Technology Renovation Fund(No.SAST2015088)the Fundamental Research Fund for the Central Universities(No.HUST2015QN093)
文摘To achieve radar and infrared stealth, an infrared stealth layer is usually added to the radar absorbing material（RAM） of stealth aircraft. By analyzing the millimeter-wave（MMW） emissivities of three stealth materials, this Letter investigates the impact of the added infrared stealth layer on the originally ＂hot＂ MMW emission of RAM. The theoretical and measured results indicate that, compared with the monolayer RAM, the MMW emission of the bilayer material is still strong and its emissivity is reduced by 0.1–0.2 at almost every incident angle.The results partially demonstrate the feasibility of detecting stealth aircraft coated with this bilayer stealth material.
基金supported by the National Natural Science Foundation of China(No.61475118)the National High-Tech Research and Development Program of China(863 Program)(No.2013AA014201)the Opened Fund of the State Key Laboratory on Integrated Optoelectronics(No.IOSKL2015KF06)
文摘A magnetic field sensor with a magnetic fluid(MF)-coated intermodal interferometer is proposed and experimentally demonstrated. The interferometer is formed by sandwiching a segment of single mode fiber(SMF) between a segment of multi-mode fiber(MMF) and a spherical structure. It can be considered as a cascade of the traditional SMF-MMF-SMF structure and MMF-SMF-sphere structure. The transmission spectral characteristics change with the variation of applied magnetic field. The experimental results exhibit that the magnetic field sensitivities for wavelength and transmission loss are 0.047 nm/m T and 0.215 d B/m T for the interference dip around 1 535.36 nm. For the interference dip around 1548.41 nm,the sensitivities are 0.077 nm/m T and 0.243 d B/m T. Simultaneous measurement can be realized according to the different spectral responses.
基金supported by the National Training Programs of Innovation and Entrepreneurship for Undergraduates of China(No.201310060015)Education Program(No.YB11-32)
文摘A novel magnetic field sensor based on optical fiber Mach-Zehnder interferometer(MZI) coated by magnetic fluid(MF) is proposed. The MZI consists of two spherical structures formed on standard single mode fiber(SMF). The interference wavelength and the power of the sensing structure are sensitive to the external refractive index(RI). Since RI of the MF is sensitive to the magnetic field, the magnetic field measurement can be realized by detecting the variation of the interference spectrum. Experimental results show that the wavelength and the power of interference dip both increase with the increase of magnetic field intensity.
