Few-mode optical fiber SPR sensing device and preparation method thereof

Abstract

The invention provides a few-mode optical fiber SPR sensing device and a preparation method thereof. The device is composed of a light source, an incident optical fiber, a 1*N optical fiber coupler, a double-clad optical fiber, an optical fiber taper, a few-mode optical fiber, an SPR sensing area and a multi-channel demodulator. One end of the incident optical fiber is connected with the light source, and the other end is connected with the 1*N optical fiber coupler, so that incident light enters the double-clad optical fiber according to a certain splitting ratio; the SPR sensing area is composed of a section of polished few-mode optical fiber and an excitation medium, the two ends of the sensing area are each connected with an optical fiber taper, and the optical fiber tapers can achieve excitation and receiving of a few-mode optical fiber mode. Then, the light emitted by the sensing area is received by the multi-channel demodulator through the optical fiber taper, and simultaneous measurement of multiple parameters can be realized by demodulating a plurality of harmonic peaks according to the characteristic that the harmonic peaks in different modes have different responses to environmental parameters such as temperature, strain and refractive index. The device has the characteristics of simple structure, high sensitivity and low manufacturing cost, and can be widely applied to the fields of biochemical sensing, drug research and development, environmental monitoring and the like.

Description

technical field [0001] The invention relates to a few-mode optical fiber SPR sensing device and a preparation method, belonging to the field of optical fiber biochemical sensing. Background technique [0002] The rapid development of optical fiber technology, as well as the continuous transformation of optical fiber communication and optoelectronic technology, have made optical fiber sensors, as an important sensor type, gradually become one of the most widely used and fastest-growing emerging directions. Optical fiber sensors not only have the advantages of small size, light weight, low cost, and high sensitivity, but also have anti-electromagnetic interference, corrosion resistance, electrical insulation, intrinsic safety, multi-parameter measurement, can be embedded (objects), and can realize remote monitoring. Features such as forming a network. Optical fiber sensing uses optical fiber as the perception and transmission medium of external information. Under the action o...

AI Technical Summary

Problems solved by technology

This patent only uses the SPR resonance peak of a high-order mode as the sensing unit, which effectively suppresses the broadening of the resonance peak, but is easily affected by other environmental parameters such as temperature

[0007] Aiming at the shortcomings of optical fiber SPR sensor spectrum broadening and multi-parameter crosstalk, the present invention proposes a fiber optic SPR sensor that uses few-mode fibers to obtain high precision and high sensitivity

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