Fig. 1. Schematic diagrams of the fabrication process of the sensor. (a)‒(e) Fabrication process of sensing interferometer; (f)‒(g) fabrication process of reference interferometer; (h) microscope image of sensing interferometer; (i) real image of reference interferometer

Fig. 2. Interference spectra of interferometers with different lengths. (a) 0.079 μm growth of sensing FPI; (b) interference spectrum of reference FPI; (c) total reflectance spectrum after superimposing spectra

Fig. 3. Experimental setup of the temperature sensing system based on single sensing FPI

Fig. 4. Experimental results of temperature measurement based on single sensing FPI. (a) Dip wavelength shift of single sensing FPI; (b) reflectance spectrum of reference FPI; (c) total reflectance spectra at different temperatures; (d) fitting curves of Vernier envelope and single sensing FPI’s dip wavelength shift

Fig. 5. Experimental setup of the temperature sensing system based on parallel structure

Fig. 6. Experimental results of temperature measurement based on parallel structure. (a)(b) Reflectance spectra at different temperatures; (c) dip wavelength shift of single sensing FPI; (d) fitting curves of Vernier envelope and sensing FPI’s dip wavelength shift

Fig. 7. Experimental results of Vernier effect based on superposition spectrum. (a) Relationship between initial phase of RFPI and dip wavelength of Vernier envelope; (b) total reflectance spectra at different temperatures; (c) fitting curves of Vernier envelope and sensing FPI’s dip wavelength shift; (d) analysis of temperature resolution