Investigation the hexagonal cylindrical absorber for bio-sensing in optical regime

Optical absorber is important for various applications like solar-cell or optical sensing such as optical imaging. This paper has investigated the various formations of the cylindrical hollow structure such as triangular, rectangular and hexagonal cross-section and shows the benefit of the hexagonal absorber for 150 THz and the parametric studies investigated for the hexagonal structure. For achieving the multiband absorber, we have used another hexagonal particle inside of the first model the same as the co-axial formation and obtained dual-band characteristic. We show that by the asymmetric model we have the ability to obtain Fano response for the prototype absorber which can be noticed for the wideband application. The electric field shows that the prototype absorber has dipole mode. Finally, we have checked the external material effect on frequency shift as a factor for material recognition. We have compared the frequency shift in hexagonal, co-axial and Fano model for various refractive indexes. The studies show that the co-axial model is more suitable for material recognition, in comparison to hexagonal and Fano models.