Design of a single‐mode photonic crystal fibre with ultra‐low material loss and large effective mode area in THz regime.

A novel low‐loss photonic crystal fibre (PCF) has been suggested for THz spectral applications. The proposed PCF contains five layers cladding with three layers core. The cladding and core region of the fibre are arranged in the octagonal and porous manner, respectively, where both the core and cladding vicinity are constituted by circular air cavities. The optical properties of the PCF are investigated by utilising the full vectorial finite‐element method along with the perfect match layers boundary condition. All numerical outcomes show the ultra‐low effective material loss of 0.049 cm−1 and large effective area of 3 × 10−7 m2 at 1 THz operating frequency. The power fraction is also considered as another significant parameter to design a low loss fibre. The almost more than half of the useful power (about 53.78% at f = 1 THz) goes through the core over the wider operating frequency. In addition this, the proposed single‐mode PCF can be fabricated using the sol–gel method and is useful not only for high data traffic transmission applications but also for THz waveguide applications. [ABSTRACT FROM AUTHOR]