Terahertz wave gas concentration sensing device

Abstract

The invention discloses a terahertz wave gas concentration sensing device, comprising a one-dimensional photonic crystal resonant cavity and a gas chamber, wherein the one-dimensional photonic crystal resonant cavity has the quality factor of more than 5,000 and comprises semiconductor substrates, a gas layer and a defect layer, and even number (which is greater than or equal to 6) of the semiconductor substrates are arranged; the defect layer is formed by gas and communicated with the gas chamber, two sides of the defect layer are provided with the semiconductor substrates with the same number, and the adjacent semiconductor substrates on the same side of the defect layer are separated through a support ring to form the gas layer; the gas layer is communicated with the gas chamber through the support ring, and the gas chamber is provided with a gas inlet and a gas outlet. The concentration information of the gas can be obtained according to the offset of a transmission peak position in a terahertz wave transmission spectrum. The gas concentration sensing device is simple in structure, and capable of working under ordinary pressure and room temperature condition of the gas chamber, a detection result cannot be influenced by the humidity, and the device is capable of meeting the demand of application in terahertz wave gas sensing field.

Description

Technical field [0001] The invention relates to a terahertz wave gas concentration sensing device, belonging to the field of terahertz wave applications. Background technique [0002] Terahertz waves are located between microwave and infrared light in the electromagnetic spectrum, with a frequency range of 0.1~10 THz, occupying a special position in the electromagnetic spectrum. Compared with other electromagnetic waves discovered now, the frequency band of terahertz pulses can cover the range from hundreds of GHz to tens of THz. The rotation and vibration of many molecules exhibit strong absorption and dispersion characteristics in this frequency band, which will produce obvious The characteristic absorption peak is unique and can be used as a fingerprint for identifying substances. Therefore, terahertz waves are suitable for the study of the electrical and acoustic properties of solids, liquids, gases and fluids, and can also be applied to environmental monitoring, biological ...

AI Technical Summary

Problems solved by technology

However, since the refractive index of gas changes very little with the gas concentration under normal pressure, the shift of the corresponding transmission peak position is also very small, and the concentration detection is very difficult.

Although there have been many reports on the research on one-dimensional photonic crystal resonators in the terahertz band, due to the insufficient quality factor and the inconspicuous movement of the transmission peak, it is difficult to meet the requirements of atmospheric pressure gas measurement.

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