An air-silica microstructure optical fiber based on the anti-resonant reflecting optical waveguide （ARROW） principle was used to develop a spectral absorption gas sensor. The ARROW fiber has an air core and an air c...An air-silica microstructure optical fiber based on the anti-resonant reflecting optical waveguide （ARROW） principle was used to develop a spectral absorption gas sensor. The ARROW fiber has an air core and an air cladding layer. An ARROW fiber with a length of 725mm was used to construct a sensing system to detect acetylene gas. The gas was injected into the fiber from one end of the fiber. The transmission spectra were collected using an optical spectrum analyzer. The results indicate that the system can detect the gas of different concentrations and has the good system linearity. The response time of the system is about 200 s.展开更多
A five-band metamaterial absorber(MMA) based on a simple planar structure is proposed.It utilizes different areas of a single unit cell to match impedance,and produces different absorptive frequencies.Numerical calcul...A five-band metamaterial absorber(MMA) based on a simple planar structure is proposed.It utilizes different areas of a single unit cell to match impedance,and produces different absorptive frequencies.Numerical calculation shows that the MMA has five different absorption peaks at 3.78 GHz,7.66 GHz,10.9 GHz,14.5 GHz and 16.7 GHz,and their absorption rates reach 95.5%,98.6%,95.7%,96.6%and 99.8%,respectively.The proposed structure is polarization insensitive for transverse electric(TE) and transverse magnetic(TM) incident waves.Also,the absorptive characteristics over large incident angles are examined.In addition,we analyze the absorption mechanism by the surface current density and power flow density distributions.This simple structure provides a way to design multi-band MMA,and also saves the cost of fabrication.展开更多
基金This work was supported by the Major Program of the National Natural Science Foundation of China （Grant No. 61290311）.
文摘An air-silica microstructure optical fiber based on the anti-resonant reflecting optical waveguide （ARROW） principle was used to develop a spectral absorption gas sensor. The ARROW fiber has an air core and an air cladding layer. An ARROW fiber with a length of 725mm was used to construct a sensing system to detect acetylene gas. The gas was injected into the fiber from one end of the fiber. The transmission spectra were collected using an optical spectrum analyzer. The results indicate that the system can detect the gas of different concentrations and has the good system linearity. The response time of the system is about 200 s.
基金supported by the National Natural Science Foundation of China(No.61475079)the Ningbo Optoelectronic Materials and Devices Creative Team(No.2009B21007)+3 种基金the Educational Committee of Zhejiang Province(No.Y201430863)the Ningbo Natural Science Foundation(No.2014A610144)the Scientific Research Foundation of Graduate School of Ningbo University(No.G15056)the K.C.Wong Magna Fund in Ningbo University
文摘A five-band metamaterial absorber(MMA) based on a simple planar structure is proposed.It utilizes different areas of a single unit cell to match impedance,and produces different absorptive frequencies.Numerical calculation shows that the MMA has five different absorption peaks at 3.78 GHz,7.66 GHz,10.9 GHz,14.5 GHz and 16.7 GHz,and their absorption rates reach 95.5%,98.6%,95.7%,96.6%and 99.8%,respectively.The proposed structure is polarization insensitive for transverse electric(TE) and transverse magnetic(TM) incident waves.Also,the absorptive characteristics over large incident angles are examined.In addition,we analyze the absorption mechanism by the surface current density and power flow density distributions.This simple structure provides a way to design multi-band MMA,and also saves the cost of fabrication.
