Hollow-core pear-shaped conjoined-tube fiber with low loss in the ultraviolet band

PCTF (pear-shaped conjoined-tube fiber) is presented as a new ultraviolet (UV) guiding fiber with low loss. Results indicate that two PCTFs have better properties than of previous studies in the UV band. The total loss less 0.01 dB/km, about orders magnitude lower hollow-core anti-resonant (ARF), and its bandwidth exceeds 150 nm between 0.2 0.4 μm. Furthermore, PCTF's single-mode performance very promising, evidenced by higher-order mode extinction ratio (HOMER) over 103. fabrication tolerance discussed this paper results show good enough to fabricate normal drawing process. This promising applications for nonlinear optics, ultrafast high power laser, quantum optics.