A low-refractive-index pcf-spr sensor operating in the mid-infrared band

Abstract

The invention relates to an optical fiber sensor, in particular to a low-refractive-index PCF-SPR sensor working in the mid-infrared band. The cladding of the optical fiber is provided with an inner layer air hole, an outer layer air hole and two symmetrically distributed circular channels for the liquid to be tested. The inner wall of the circular channel for the liquid to be tested is coated with a gold film. There are tiny openings on the outer side; the air holes in the inner layer and the air holes in the outer layer are arranged in a regular hexagonal staggered shape, and the radius of the outer layer air holes is larger than the radius of the inner layer air holes; the material of the optical fiber is silica, and the optical fiber has a refractive index of Guided photonic crystal fiber. The resonance wavelength is in the mid-infrared band, which can detect the liquid to be tested with low refractive index, and can selectively filter the particles in the solution to be tested. It is small in size and easy to realize the miniaturization of the sensor. The average spectral sensitivity is as high as 8850 nm / RIU. The invention is mainly used for detecting the refractive index of the solution to be measured and selectively detecting and analyzing the chemical substances in the solution.

Description

[0001] Technical field: [0002] The invention relates to an optical fiber sensor, in particular to a low refractive index PCF-SPR sensor working in the mid-infrared band. [0003] Background technique: [0004] Surface plasmon resonance (SPR) sensing technology is currently a rapidly developing optical sensing technology. In addition to the general characteristics of optical sensors, surface plasmon resonance sensors also have outstanding features such as high sensitivity, no marking, and real-time detection. They have broad prospects in the fields of biology, drug research and development, medical diagnosis, energy, and environmental pollution. The application prospect of optical fiber sensor is very wide, not only small size, light weight, easy to form a network, but also anti-electromagnetic interference, anti-corrosion, high sensitivity, and bendable light path. However, the traditional optical fiber sensor still has many shortcomings that are difficult to solve, such as poor p...

AI Technical Summary

Problems solved by technology

However, most of the previously proposed PCF-SPR sensors work in the range of visible light or near-infrared light, and the measured refractive index of the liquid to be tested is generally above 1.3, which are two difficulties that need to be overcome in this field.

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