Plasma resonance refractive index sensor of D-type photonic crystal fiber based on hole cutting type

Abstract

The invention discloses a plasma resonance refractive index sensor of a D-type photonic crystal fiber based on a hole cutting type, and belongs to the technical field of photonic crystal fiber sensing. The plasma resonance refractive index sensor comprises: a D-type photonic crystal fiber; the D-type photonic crystal fiber comprises a fiber core and a wrapping layer wrapping the fiber core; the wrapping layer is provided with a circular arc curved surface and a polishing surface, and the polishing surface is covered with a metal layer; a plurality of through air holes are formed in the wrapping layer along the axial direction of the fiber core; the air holes comprise two D-shaped holes which are symmetrically arranged on the left side and the right side of the fiber core and circular hole arrays which are arranged on the peripheries of the D-shaped holes. The cut hole type D-type structure further improves the excitation efficiency of SPR, enhances the interaction between an analyte and the fiber core, and can realize high-sensitivity sensing with a refractive index sensing interval of 1.35-1.45. And within the refractive index interval of 1.35-1.45, the maximum spectral sensitivity of the sensing performance reaches 10450nm / RIU, which is far higher than that of a traditional optical fiber sensor.

Description

technical field [0001] The invention relates to the technical field of photonic crystal fiber sensing, in particular to a plasma resonance refraction index sensor based on a hole-cut D-type photonic crystal fiber. Background technique [0002] Surface Plasmon Resonance (SPR) describes a phenomenon that occurs at the interface between a metal and a medium, and the incident light excites conduction electrons in the metal, causing them to collectively oscillate. Because the SPR effect is extremely sensitive to the detection of refractive index changes, SPR sensors have been widely used in the research of biochemical detection. [0003] In the prior art, the traditional prism-type SPR sensor is difficult to miniaturize and the system is complex and difficult to package and implement. It can only be used in the laboratory, and has limitations in the detection of the external environment and long-distance detection. The optical fiber structures of miniaturized SPR sensors cannot ...

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Problems solved by technology

[0007] Patent CN110376161A discloses a D-type photonic crystal fiber refractive index sensor using dual loss peak detection. The two loss peaks of the sensor are respectively located in two different bands of long and short wavelengths, which provides a good choice of observation spectrometer for practical applications Compatibility and substitution; however, the analytical range of the refractive index of the analyte liquid to be tested by the sensor is 1.377-1.385, and the detection range of the sensing parameter is narrow

Patent CN112098339A discloses a multi-parameter sensor of D-type photonic crystal fiber surface plasmon resonance, which can realize multi-parameter simultaneous detection of temperature, magnetic field strength and refractive index, but its fiber structure is relatively complicated, and the light field distribution is relatively scattered

Patent CN109596573A discloses a new D-type structure photonic crystal fiber sensor based on surface plasmon resonance. The refractive index range of the liquid to be measured is 1.33-1.39, but the linear fitting degree in this refractive index range is not good. good

[0008] In summary, although there are many reports on the D-type SPR-PCF sensor in the prior art, there is still a lot of room for improvement in the detection range, sensitivity and linearity of the sensing parameters.

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