Abstract-Design of terahertz spectroscopy based optical sensor for chemical detection

• Shuvo Sen, 
• Kawsar Ahmed

https://link.springer.com/article/10.1007/s42452-019-1247-0

In this article, a new design of circular cladding with a rotated-hexacore in photonic crystal fiber (RH-CPCF) has been suggested for chemical sensing application in the THz regime. The five layers circular cladding and two layers rotated-hexacore in circular shape are designed here. All numerical results are obtained with a procedure of finite element method and perfectly match layered boundary condition in terahertz (THz) wave propagation. After the simulation result, the proposed RH-CPCF shows the high relative sensitivity is 76.44%, 77.16% and 73.20% for three chemicals such as Ethanol (n = 1.354), Benzene (n = 1.366) and Water (n = 1.330) at 1 THz. On the other hand, the low confinement losses are 2.33 × 10⁻⁰³ dB/m, 3.07 × 10⁻⁰⁶ dB/m and 2.84 × 10⁻⁰² dB/m for same in three chemicals at 1 THz. Moreover, effective area, effective mode index and total power fraction in core air holes are also briefly described here. In addition, this proposed circular photonic crystal fiber (RH-CPCF) can be used especially for chemical sensing in biomedical, industrial quality control, material research, micro-optics and many communication applications in THz technology.