An anti-resonant hollow-core fiber

Abstract

The present invention provides an anti-resonant hollow-core optical fiber. The optical fiber is composed of a first-type dielectric tube, a second-type dielectric tube and a first-type dielectric layer, including a high-refractive-index cladding region and a low-refractive-index core region. Both the first-type medium pipe and the first-type medium layer are connected to the second-type medium pipe. The area surrounded by the outer wall of the first-type dielectric tube close to the core region is the fiber core area (the first-type hole). A second-type hole is isolated between the first-type medium pipe and the first-type medium layer, and a third-type hole is isolated between the first-type medium pipe and the second-type medium pipe. The fiber core has a negative curvature boundary, the fiber has multiple anti-resonant layers, and the fiber cladding has no nodes, which effectively reduces the leakage loss, and the fiber has no loss peaks caused by lateral nodes, which increases the transmission bandwidth. In addition, the fiber modes are mainly distributed in air holes, which can effectively reduce the material absorption loss of the fiber, increase the damage threshold of the fiber, and effectively transmit high-power laser and terahertz waves.

Description

technical field [0001] The invention relates to the field of optical fiber design, in particular to an anti-resonant hollow-core optical fiber. Background technique [0002] The application of optical fiber can realize high-speed and large-capacity communication, and it is an indispensable information transmission technology. With the development of optical fiber transmission technology, anti-resonant hollow-core optical fiber is becoming more and more dominant in realizing high-bandwidth, low-loss optical transmission. This fiber is hollow, and the transmission rate of optical signals can be 30% higher than that of traditional solid-core fibers, and can reach 99.7% of the speed of light, which also makes it an important driver for the development of optical fiber communications, lasers, nonlinear optics and other fields force. [0003] The researchers hope that AR-HCF can reduce losses by simply adding anti-resonant layers like HC-PBGF. Later, it was found that nesting m...

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Problems solved by technology

Later, it was found that nesting multi-layer dielectric tubes inside the dielectric tube of the anti-resonance layer can make the confinement loss lower than the surface scattering loss, but because the current preparation conditions are not developed enough, the thickness, position and shape of each dielectric layer are difficult to be accurate control

W. J. Belardi et al [W. Belardi, Design and properties of hollow antiresonant fibers for the visible and near infrared spectral range. J. Lightw. Technol., 2015, 32:4497~4503] prepared nested negative curvature hollow core fiber, The loss is 175dB / km, because the wall thickness of the two dielectric tubes in the cladding is quite different, and the position and size of the small dielectric ring are different, which affects its fiber characteristics

In 2018, Wang Yingying and others from Beijing University of Technology [Shou-fei Gao, Ying-ying Wang, Wei Ding, et al. Hollow-core conjoined-tube negative-curvature fiber with ultralow loss[J]. Nature Communications, 2018, 9(1 )] published a connected tubular multi-resonator AR-HCF structure with nodes. The researchers did not try to remove the cladding nodes, but weakened the coupling between the cladding mode and the core mode at the nodes to reduce the fiber loss through precise control. However, this technology will increase the nodes in the fiber cladding, which will cause too many cladding modes. During the fiber preparation process, it needs to be precisely adjusted to avoid the influence of the cladding modes at the nodes.

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