An Ultra-Thin Multiband Refractive Index-Based Carcinoma Sensor Using THz Radiation

Abstract

A novel multiband terahertz (THz) refractive index-based carcinoma sensor is designed and investigated in this paper. The proposed THz sensor is constructed using meandered sectoral stubs enclosed in a square loop. The proposed sensor has a footprint of <inline-formula> <tex-math notation="LaTeX">$1.019 \lambda _{eff} 1.019 \lambda _{eff}$ </tex-math></inline-formula> and operates at three distinct frequencies, viz. 1.095 THz, 2.865 THz, and 4.065 THz. The absorption characteristics of the sensor are analyzed to estimate the performance of the proposed sensor. The free space absorptivity is estimated as 99.6&#x0025;, 99.1&#x0025; and 99.2&#x0025; at the said three resonant frequencies. The peak Q factor of 22.58 is realized at 4.065 THz under free space unloaded condition. Further, a study on different design parameters on absorption peaks and polarization independency is conducted and the results are presented. Followed by these, the sensitivity performance of the proposed carcinoma THz sensor is analyzed for healthy and cancerous cells of blood, skin and breast based on their unique refractive index profile. The peak sensitivity of 514.28 GHz/RIU at 2.865 THz, 476.35 GHz/RIU at 4.065 THz, and 476.91 GHz/RIU at 4.065 THz is theoretically observed for blood, skin and breast cancer cells respectively. Similarly, the high Q factor of 21.85, 18.06, 19.21 at 4.065 THz with FoM of 2.8, 2.38 and 2.384 are also observed for blood, skin and breast cancer respectively. Furthermore, the influence of the sample thickness on the THz sensor performance is analyzed. Thus, the proposed THz sensor is a promising entity for the detection and early diagnosis of cancer cells using THz radiation.