Biochemical sensor based on thin-covering layer long-period fiber grating coupling resonant cavity

Abstract

The invention provides a biochemical sensor based on a thin-covering layer long-period fiber grating coupling resonant cavity, which comprises a microsphere resonant cavity, a thin-covering layer long-period fiber grating and a carrying silicon substrate, wherein the microsphere resonant cavity is coated with nano-pore zeolite coatings, the microsphere resonant cavity coated with nano-pore zeolite coatings and the thin-covering layer long-period fiber grating are fixed on the carrying silicon substrate engraved with micro grooves and hole grooves, and the distance between the microsphere resonant cavity and the thin-covering layer long-period fiber grating is controlled in a range between dozens of nanometers and hundreds of nanometers through the micro positioning of the carrying silicon substrate, wherein the resonant cavity is in a fractographic resonant mode, and the surface of the resonant cavity generates the fractographic change when the nano-pore zeolite coatings absorb molecules to be detected, so the resonant wavelength is deviated, and the detection is further carried out. The detection on the specified molecules can be realized according to the different hole diameters of the coatings of a zeolite molecular sieve, in addition, the sensitivity can reach the ppm range level or even the ppb range level, and the invention can be widely used in the fields of environment control, industrial process treatment, public safety and the like.

Description

field of invention [0001] The invention belongs to the field of miniature sensors, in particular to evanescent wave coupling of light and silicon substrate micro-positioning. The coupling between the thin-clad long-period fiber grating and the microsphere resonant cavity coated with zeolite film on the surface is used, and the offset of the resonant wavelength is used. To achieve the detection of specific molecular concentration. technical background [0002] Commonly used resonator structures include disks, rings, columns, spheres, etc. These gyratory resonators support high quality factor whispering gallery modes (whispering gallery modes, referred to as WGMs). WGMs are a mode that depends on the topography resonance. The resonant mode frequency of the microcavity depends on the size of the resonant cavity, and the mode frequency of the microcavity can be tuned by changing the surface topography of the cavity. The waveguide structures commonly used to excite the resonator...

AI Technical Summary

Problems solved by technology

The precision of the instrument required for this adjustment is high, it is difficult to accurately control the actual distance between the two, and the operation is difficult, it is difficult to ensure that the waveguide is tangent to the equatorial plane of the resonant cavity, and the repeatability is poor.

Images