Micro optical fiber gas sensor covered by adopting graphene

Abstract

The invention discloses a micro optical fiber gas sensor covered by adopting graphene and relates to the field of gas sensors, in particular relates to the field of an optical fiber intermodal interference sensor. A micro optical fiber which is drawn to have two thick ends and thin middle through a fused biconical taper method is arranged on a magnesium fluoride substrate, a single-layer graphene material covers the middle section of the micro optical fiber, and because the single-layer graphene material is extremely sensitive to chemical bonds between atoms and an extranuclear electron state is extremely sensitive to an ambient environment, distribution of a dielectric constant is changed due to contact between the material and trace gas molecule, so that the optical refractive index is changed, and finally the intermodal interference spectrum of light propagated in the optical fiber is changed, the gas types are identified by detecting the interference spectrum, and the aims of the gas sensor are achieved. Therefore, the micro optical fiber gas sensor has the advantages of small size, high precision, high sensitivity, stability in operation and repeated utilization effect.

Description

technical field [0001] The invention relates to the field of gas sensors, in particular to the field of optical fiber intermode interference gas sensors. Background technique [0002] Gas sensors are widely used in the detection of toxic, flammable, explosive, and other gases, and are the terminals of the environmental Internet of Things. In the pollution control of papermaking, oil refining, etc., the gas must be inspected before it is allowed to be discharged; in the process of metal smelting, organic chemical production, etc., the gas composition control of the production environment directly determines the quality of chemical products; in the biomedical field, drug quality inspection The invention and application of sensors with small size, low energy consumption and no chemical side effects will directly drive the technological progress in this field. [0003] However, the existing optical gas sensors generally rely on the interaction between gas molecules and optical ...

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Problems solved by technology

The device has the following defects: 1. The optical fiber is located on the graphene layer, and the contact area is small. After the graphene absorbs the gas molecules, the influence rate of the light propagating in the optical fiber is limited; 2. The method changes the light in the optical fiber after the graphene absorbs the gas molecules. Intensity, the type of gas can be judged by demodulating the light intensity output by the device, which has low sensitivity, long response time, and small dynamic range; 3. The graphene layer area of ​​the post-attached sensing structure is too large, which is easily affected by the surrounding environment. less reliable

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