Low-loss single-mode modified conjoined tube hollow-core fiber

Abstract

We explain the effects of cladding geometries on conjoined tube hollow-core negative curvature fibers and offer a modified conjoined tube negative curvature fiber with appropriate positioning of an additional negative curvature D-shaped layer joining the flat bar to reveal attractive performances over existing recent related fibers. The proposed fiber ensures the least loss of 0.003 dB/km at 1.43 µm, a ∼ 0.04 d B / k m loss covering the wide bandwidth of approximately 300 nm, the lowest surface scattering loss of ∼ 0.02 d B / k m , and the lowest microbending loss of ∼ 0.04 d B / k m , thus providing a propagation loss of 0.10 dB/km at the 1.55 µm wavelength and also offering excellent bend loss performance ( ∼ 0.015 d B / k m loss at a 7 cm bend radius). The fiber, with a core diameter of 30.50 µm, also shows a higher-order mode extinction ratio of ∼ 1600 and maintains greater than 100 over most of the telecom bands; hence, it effectively provides single-mode operation. We show the potential of conjoined tube hollow-core negative curvature fibers in optical communications systems.

Low confinement loss single-mode hollow core anti-resonant fiber covering the O + E + S + C + L + U band

“…At present, the main research of HC-ARF loss is focused on confinement loss (CL) and mainly realizes various properties through the design of cladding structure. The designs that have emerged in this study are single ring, 16 “ice cream cone” shaped, 28 lotus-shaped, 21 nested rings, 17 , 26 connecting tubes, 24 elliptical tubes, 18 , 19 and double negative curvature tubes 20 , 22 …”

“…But this structure cannot be well fabricated in reality 23 . Shaha and Khaleque 24 provided an improved connected tube negative curvature fiber with a loss of 0.003 dB/km at 1.43 μm, covering a 300 nm bandwidth of ∼0.04 dB/km, and with a high-order mode extinction ratio of ∼1600. Guo et al.…”

“…8 The optical fibers that guide light through IC are Kagome fibers 15 and hollow core anti-resonant fibers (HC-ARFs). [16][17][18][19][20][21][22][23][24][25][26] The Kagome structure solves the bandwidth problem of PBGF and provides a conceptual tool for inducing negative curvature, but the presence of many nodes and airmedium contact surfaces in the fiber causes additional Fano resonances, 27 which limits the loss. Therefore, the combination of anti-resonant and negative curvature in HCF has attracted a great deal of interest.…”

“…At present, the main research of HC-ARF loss is focused on confinement loss (CL) and mainly realizes various properties through the design of cladding structure. The designs that have emerged in this study are single ring, 16 "ice cream cone" shaped, 28 lotus-shaped, 21 nested rings, 17,26 connecting tubes, 24 elliptical tubes, 18,19 and double negative curvature tubes. 20,22 As an example, Kolyadin et al 16 found that the introduction of separation between the cladding capillaries eliminated additional resonances in conventional HCFs, further reducing CL, and since then the focus has been on nodeless HCFs.…”