Fig. 5: Spectral characterization of the nested capillary resonator.

a Measured WGM spectra of the LC filled nested capillary structure at different air flow rates, b selected spectral dip at 1551.5 nm versus the flow rate, c WGM spectra of the nested capillary resonator measured at different temperatures, d linear fitting of the spectral shift data versus temperature for the selected dip at 1551.6 nm in figure (c), e experimental WGM spectra of the nested capillary resonator without LC filling, f selected spectral dip versus the flow rate. (WGM: whispering gallery mode, LC: liquid crystal, sccm: nm·min·mL⁻¹). (Note: Error bars were calculated using standard deviation of measurements for five times).