Author Affiliations
1School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China2Key Laboratory of Opto-Electronics Information Technology, Ministry of Education, Tianjin 300072, China3Institute of Optical Fiber Sensing, Tianjin University, Tianjin 300072, Chinashow less
Fig. 1. Multi-beam interference model of Fabry-Perot microcavity
Fig. 2. Reflected beam and fiber coupling model of Fabry-Perot cavity
Fig. 3. Configuration of three spliced air gap-based Fabry-Perot sensor
[38] Fig. 4. Experiment results of all-sapphire single-crystal fiber Fabry-Perot sensor fabricated by femtosecond laser micro-machining and CO
2 laser welding
[40]. (a)(b) Microscopic and scanning electron microscopic image of the bottom surface of the pit before the CO
2 laser surface smoothing; (c)(d) corresponding microscopic and scanning electron microscopic image after the CO
2 laser surface smoothing; (e) image of the laser-welded sensor head (the inset shows the image of at the welding plane); (f) image of the fabricated sensor head
Fig. 5. Schematic diagrams of thin-film fiber-optic Fabry-Perot microcavity sensor and sensing system
[41] Fig. 6. Schematic diagram of 45° inclined fiber diaphragm sensor head
[46]. (a) Sensing optical path diagram of 45°inclined optical fiber diaphragm sensor;(b) axial diagram of 45° inclined fiber diaphragm sensor
Fig. 7. Actual picture of the flame experiment of the patch type sapphire fiber Fabry-Perot sensor
Fig. 8. Parallel dual-waveguide Fabry-Perot high temperature sensor
[50]. (a) Structure diagram of the sensor; (b) schematic diagram of the sensing optical path
Fig. 9. Schematic diagram of laser micromachined composite Fabry-Perot sensor
[51] Fig. 10. Micrograph of the composite fiber-optic Fabry-Perot sensor made by the etching method combined with the optical fiber splicing technology
[52] Fig. 11. Special fiber splicing composite Fabry-Perot sensor
[53]. (a) Schematic diagram; (b) micrograph
Fig. 12. Structure and sensing characteristics of all-silicon dual-cavity optical fiber pressure sensor
[55]. (a) Schematic diagram of the all-silicon-based dual-cavity fiber-optic pressure sensor structure (all the components are high-temperature resistant materials); (b) interference model of the dual-cavity structure with three reflective mirrors; (c) simulation of reflected spectra
IR(
λ) (simulation parameters:
n1=1,
n2=3.47,
L1=60 μm,
L2=300 μm,
I0 is the light intensity of a broadband light source with a central wavelength of 1550 nm)
Fig. 13. Schematic diagram of structure and sensing principle of pure sapphire crystal bonded F-P sensor
[56]. (a) Schematic of the sensor structure; (b) sensor sensing principle and spectrum curve diagram