Study On Sensing Properties Of Photonic Crystal Fiber Filled With Materials

Optical fiber sensing technology is based on optical fiber as the carrier of light.When the external environment changes,the properties parameters of the light wave will be mod-ulated and the objective of sensing measurement of external physical quantity is realized.Because of its high sensitivity,corrosion resistance,anti-interference,small interference in the measurement,and repeatable cross use,the research of optical fiber sensors has attracted more and more attention.Photonic crystal fiber(PCF)has excellent performances,such as highly adjustable dispersion,no cut-off single mode transmission,high birefringence and flexible nonlinear control,which are not found in traditional optical fibers.By filling opto-electronic functional materials in the pores of the PCF can further improve the transmission performance of the optical fiber,it is hopeful to make further use of material filled PCF to develop a more sensitive optical fiber sensor.Firstly,the research background of PCF and the research on the sensing characteristic-s of material filled PCF are introduced in detail.The theoretical basis and main research methods of the characteristics of PCF are summarized.Secondly,we design a refractive index sensor based on gold wire selective filling PCF.The fiber core is filled with high refractive index analysis solution,which makes it a refractive index guided fiber and high refractive index measurement.The large hole is filled with gold wire,so the surface plasmon mode is only coupled to the x polarization of the core mode.The refractive index sensing properties of the PCF are studied by the principle of total reflection and the resonance of the surface plasmon.Thirdly,a Sagnac interferometric temperature sensor based on absolute ethanol filled PCF is designed.The cladding air holes are arranged in the hexagon with the same aperture and same hole spacing.Removing the air holes on both sides of the core makes the PCF with high birefringence.The fiber is fully filled with ethanol.The interferometric principle is applied to study the temperature sensing characteristics of PCF.The temperature range and temperature sensitivity of the intercept PCF will be different when the length of the PCF is different.Compared with the transmission and sensing properties of three kinds of PCF filled with different air holes,the full filling can make the temperature sensing measurement of the PCF reach a higher sensitivity and a wider range of temperature than the selective filling.Finally,the experimental measurement on the temperature sensing of the self-made PCF in the laboratory is carried out by building an experimental platform.The pore structure of fiber is filled with anhydrous ethanol or castor oil.The transmission spectrum of optical PCF is measured by broadband source.An intensity type PCF temperature sensor is realized.It is found that the sensitivity and linearity of the optical fiber sensor after filling with absolute ethanol is high.The sensitivity can reach 153.12 counts/? and linearity is up to 0.999.