Extremely high birefringent and low loss microstructure optical waveguide: Design and analysis

In this paper a new kind of porous core microstructure fiber is proposed and analyzed for the efficient transmission of terahertz signal. We use hexagonal type air hole instead of conventional circular air hole to produce hexagonal structure in cladding. Rectangular shaped air holes are introduced in the core to provide higher birefringence than other structures. Full vector finite element method is used to investigate the guiding characteristics of that hybrid waveguide. The numerical analysis ensures that, the proposed fiber offers extremely high birefringence of 0.075 and ultralow effective material loss of 0.045 cm(-1) simultaneously at optimum designing condition. Along with the excellent guiding characteristics this fiber exhibits very high power fraction of 47% and very low dispersion variation of 0.17 ps/THz/cm over 600 GHz frequency range. The proposed fiber can be easily fabricated by using the ongoing technology. We hope this microstructure fiber will be a good candidate in different polarization maintaining applications.