Exploring Tamm State for Enhanced Third Harmonic Wave Generation in Cutting-Edge Biosensing Applications

The study in this article investigates the propagation characteristics of a designed hyperstructure (HS) internal fundamental wave (FW) and third harmonic wave (THW). It also explores method to enhance the conversion efficiency of THW through the utilization of Tamm state. The results show that, compared to previous analytical techniques relying on localized fields near the bandgap edge or pursuing quasi-phase matching (QPM), Tamm state demonstrates a significant 8–14 orders-of-magnitude improvement in THW. This improvement is attributed to its heightened electric field energy density and extended group delay. The transfer matrix method (TMM) is utilized to analyze the scattering effects of electromagnetic (EM) waves in the HS, effectively capturing multiple reflections and interference phenomena at the interfaces between various homogeneous media. Additionally, an auxiliary cancer cell cavity is introduced between the front and back reflection cavities. By leveraging alterations in refractive index (RI) during cell carcinogenesis, it functionally shifts the THW spectrum. The performance parameters for applications in basal, breast, and cervical cells are presented in this article, including a high sensitivity of 52 terahertz (THz)/RIU, a linear range of RI spanning from 1.35 to 1.40, a variation range in quality factor from $1.2788 \times 10^{5}$ to $2.8673 \times 10^{6}$ , as well as a figure of merit (FOM) variation range from $1.7887 \times 10^{4}$ to $3.9901 \times 10^{5}$ .