High precision liquid refractive index sensor

Abstract

The invention discloses a high precision liquid refractive index sensor based on a sub-wavelength optical grating structure, and belongs to the field of biophoton sensing. The high precision liquid refractive index sensor is composed of a substrate plate, a sub-wavelength optical grating, and a microfluid channel; the sub-wavelength optical grating guided-mode resonance is adopted to realize liquid refractive index high precision measuring. When the liquid refractive index in the microfluid channel is changed, the center wavelength of the transmission spectrum of the optical grating is changed, the center wavelength is firmly related with the value of liquid refractive index. The liquid refractive index can be obtained through measuring the transmission spectrum center wavelength. The highprecision liquid refractive index sensor is a novel sensor used for measuring liquid refractive index, is simple in structure, is convenient to prepare, is high in measuring precision, and is promising in application prospect in the fields of biological sensing, chemical analysis, and medical diagnosis.

Description

technical field [0001] The invention belongs to the technical field of biophoton sensing, and in particular relates to a high-precision liquid refractive index sensor. Background technique [0002] Liquid is one of the basic forms of matter in nature, and the refractive index of liquid is an important parameter reflecting the physical properties of liquid. The purity or concentration of a liquid usually has a direct impact on its refractive index, so obtaining the refractive index of a liquid quickly and accurately is of great significance for many fields such as chemical analysis, medical diagnosis, environmental monitoring, and food production. Generally, there are many methods for measuring the refractive index of liquids, such as Abbe refraction method, Michelson interferometry, surface plasmon method, etc., but these methods usually have disadvantages such as poor measurement accuracy, large environmental influence, or complex device structure. [0003] In recent years...

AI Technical Summary

Problems solved by technology

Generally, there are many methods for measuring the refractive index of liquids, such as Abbe refraction method, Michelson interferometry, surface plasmon method, etc., but these methods usually have disadvantages such as poor measurement accuracy, large environmental influence, or complex device structure.

[0003] In recent years, various liquid refractive index sensors based on grating structures have been proposed, such as waveguide grating liquid refractive index sensors, fiber grating liquid refractive index sensors, Bragg grating liquid refractive index sensors, etc. However, these sensors usually have measurement There are many outstanding problems such as small range, low measurement accuracy, or high cost, so it is subject to many restrictions in practical applications

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