Influence of the geometry of terahertz chiral metamaterial on transmission group delays

Recently, group delay has been proven as a very convenient tool for control of terahertz electromagnetic signals used for filters, waveguides and polarization components. Here, we investigate the propagation of circularly polarised terahertz pulse via analysis of group delays in Ω particle chiral metamaterial. When varying the geometry of the Ω particle chiral metamaterial, significant modification of chiroptical effects—optical activity and circular dichroism can be observed. Through the analysis of group delays in the frequency region between 1 and 3 THz we conclude that the right circularly polarised wave is more sensitive to changes in the geometry than the left circularly polarised wave. This result implies that the right circularly polarised wave is responsible for variation of chiroptical effects in these structures and opens up a possibility for potential applications.