Analytical method for biochemical sensors based on tandem LPWG

Abstract

The invention discloses an analysis method of a biochemical sensor based on a series LPWG. By utilizing the coupling characteristics of the LPWG, light in a certain bandwidth range centered on the resonant wavelength in the incident light wave is coupled into the measured envelope through the LPWG1, and then passes through the LPWG2. This part of the light is coupled into the waveguide core layer, and the output is interfered with the fundamental mode propagating in the same direction in the waveguide core layer. When the measured substance changes, the resonance wavelength in the output spectrum will shift, and the measured substance concentration can be calculated by detecting the offset. Analyze the absorption spectrum signal of the liquid in the output spectrum to realize the characterization of the measured substance. On the one hand, the method of the invention solves the problem that traditional biochemical sensors rely on a specific sensitive film with high price and a single detection index to be qualitative; limit problem.

Description

technical field [0001] The invention belongs to the fields of integrated optics, biophotonics and spectrum analysis, and specifically relates to the mode coupling and transmission characteristics of long-period waveguide gratings, and qualitative and quantitative analysis models and methods in biochemical sensing mechanisms. Background technique [0002] At present, for the biochemical sensors developed at home and abroad, whether they are based on electrochemical principles, microfluidic technology or optical principles for detection, biochemical sensitive films are usually deposited on the contact surface between the device and the measured substance. The adsorption of specific substances by the membrane or the physical and chemical changes with them are used to select and distinguish the measured substances, and larger prisms and optical circulators are required. This design scheme not only increases the design complexity of the device, but also increases the size and cos...

AI Technical Summary

Problems solved by technology

Usually the substance to be detected needs to be sent into the detection area through water as a solvent and as a carrier. If the selected detection light source band contains the absorption information of water, the quantification cannot be completed or will have a great impact on the quantitative results.

In this case, only the detection light source of a specific wavelength band can be selected, which limits the detection range

Especially in the mid- and far-infrared bands, the fundamental frequency absorption information of almost all substances (including biochemical gases and liquids) is in the mid- and far-infrared bands, and the absorption coefficient of substances is 1 to 2 orders of magnitude larger than that in the near-infrared band, which will greatly improve the detection sensitivity. , however, in the mid-to-far infrared band, the absorption of water is very strong, the emergence of this challenging problem brings great troubles to biochemical detection

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