One-dimensional symmetric phononic crystals sensor: towards salinity detection and water treatment

In this research study, we designed a 1D PnC sensor to monitor the smallest changes in the concentrations of NaCl. Here, we have considered a symmetric 1D PnC consisting of two mirror PnC designs, and a cavity layer filled with NaCl solution in-between. The proposed sensor manipulates two concentration ranges: low range 0-4% (seawater concentrations) and high range 0-60% (industrial concentrations). In the transmission spectra, a localized resonant mode shifts towards lower frequencies (7.6706 x 10(5) Hz-7.6559 x 10(5) Hz) with increasing the salinity concentration (0-4%). Moreover, all resonant modes have roughly high transmission intensity (99%). Also, the displacement of these modes, sensitivity, and other parameters are greatly changed when the concentration grows from 0 to 60%. In addition, we have discussed the effect of fabrication tolerance on the performance of the suggested sensing tool. Meanwhile, the numerical results demonstrated a negligible effect of this parameter on the performance of the proposed sensor. Therefore, we believe that the present sensor is better than 1D and 2D PnC, electrochemical and optical designs. In particular, it may be characterized by radiation losses reduction and high stability with temperature changes.

Automated summary

In this research study, a 1D photonic crystal (PnC) sensor was designed to monitor small changes in the concentration of NaCl. Experimental results showed that the resonant frequency of the localized mode shifted to lower frequencies with increasing salinity concentration, leading to significant changes in sensitivity and other parameters. Additionally, the effect of fabrication tolerance on sensor performance was found to be negligible. Overall, this sensor design exhibits lower radiation losses and higher stability with temperature changes compared to other 1D and 2D PnC, electrochemical, and optical designs.