Optical sensor on basis of cascade connection of double resonant cavities

Abstract

The invention discloses an optical sensor on the basis of cascade connection of double resonant cavities. The optical sensor comprises a broadband light source and the two resonant cavities. The surfaces of one of the resonant cavities are in contact with to-be-measured liquid, and the resonant cavity is a reference resonant cavity; a surface of the other resonant cavity is modified by a biological molecular film, and the other resonant cavity is in contact with the to-be-measured liquid and is a sensing resonant cavity; the two resonant cavities are coupled with each other by a common straight waveguide. The optical sensor has the advantages that to-be-measured substances in the to-be-measured liquid can be adsorbed by the biological surface film of the sensing resonant cavity, the effective refractive index of the sensing resonant cavity can change, but the effective refractive index of the reference resonant cavity does not change, accordingly, spectra generated after cascade connection is carried out on the two resonant cavities change, and output light intensity can ultimately change; change of output power can be measured, and accordingly content information of the to-be-measured substances in the to-be-measured liquid can be acquired.

Description

technical field [0001] The invention relates to an optical sensor, in particular to an optical sensor based on double resonant cavity cascade connection. Background technique [0002] Optical sensing technology has the advantages of anti-electromagnetic interference, high sensitivity and high integration, and has a wide range of applications in the fields of environmental detection, food safety and biomedicine. In recent years, in order to improve the sensitivity of the sensor, the optical sensor based on the vernier effect has become a research hotspot. However, because the reference resonant cavity has an upper cladding and is not in contact with the measured liquid, and the sensing resonant cavity is in contact with the measured liquid, the upper cladding of the two is different, resulting in the temperature sensitivity of the two resonant cavities It is also different from the dispersion characteristics, so the interference of this kind of sensor due to the change of ex...

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Problems solved by technology

However, because the dispersion characteristics of the two resonators are different, the free spectral ranges of the two resonators are different in a wide wavelength region, so the sensitivity of this sensor is not high.

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