Confinement loss in hollow-core negative curvature fiber: A multi-layered model

Abstract Hollow-core negative curvature fibers (HC-NCFs) have become one of the research hotspots in the field of optical fiber because of its potential applications in the data and energy transmissions. In this paper, a new kind of single-polarization single-mode HC-NCF with nested U-type cladding elements is proposed. To achieve the single-polarization single-mode transmission, we use two different silica tube thicknesses that satisfy the resonance and anti-resonance conditions on the U-type cladding elements and the cladding tubes, respectively. Besides, the elliptical elements are introduced to achieve good single-mode performance. By studying the influences of the structure parameters on the propagation characteristics, the optimized structure parameters are obtained. The simulation results show that when the wavelength is located at 1550 nm, the single-polarization single-mode transmission is achieved, along with the polarization extinction ratio of 25749 and minimum high-order mode extinction ratio of 174. Furthermore, the confinement loss is only 0.0015 dB/m.

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Hollow-Core Negative Curvature Fiber with High Birefringence for Low Refractive Index Sensing Based on Surface Plasmon Resonance Effect

Sensors ◽

10.3390/s20226539 ◽

2020 ◽

Vol 20 (22) ◽

pp. 6539

Author(s):

Shi Qiu ◽

Jinhui Yuan ◽

Xian Zhou ◽

Feng Li ◽

Qiwei Wang ◽

...

Keyword(s):

Negative Curvature ◽

Resonance Effect ◽

Confinement Loss ◽

Hollow Core ◽

Analysis Method ◽

High Birefringence ◽

Surface Plasmon Resonance Effect ◽

Loss Method ◽

Gold Wires ◽

Low Refractive Index

In this paper, a hollow-core negative curvature fiber (HC-NCF) with high birefringence is proposed for low refractive index (RI) sensing based on surface plasmon resonance effect. In the design, the cladding region of the HC-NCF is composed of only one ring of eight silica tubes, and two of them are selectively filled with the gold wires. The influences of the gold wires-filled HC-NCF structure parameters on the propagation characteristic are investigated by the finite element method. Moreover, the sensing performances in the low RI range of 1.20–1.34 are evaluated by the traditional confinement loss method and novel birefringence analysis method, respectively. The simulation results show that for the confinement loss method, the obtained maximum sensitivity, resolution, and figure of merit of the gold wires-filled HC-NCF-based sensor are −5700 nm/RIU, 2.63 × 10−5 RIU, and 317 RIU−1, respectively. For the birefringence analysis method, the obtained maximum sensitivity, resolution, and birefringence of the gold wires-filled HC-NCF-based sensor are −6100 nm/RIU, 2.56 × 10−5 RIU, and 1.72 × 10−3, respectively. It is believed that the proposed gold wires-filled HC-NCF-based low RI sensor has important applications in the fields of biochemistry and medicine.

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Influence Factors of Confinement Loss of Negative Curvature Hollow Core Fiber

Laser & Optoelectronics Progress ◽

10.3788/lop56.050602 ◽

2019 ◽

Vol 56 (5) ◽

pp. 050602

Author(s):

陈翔 Chen Xiang ◽

胡雄伟 Hu Xiongwei ◽

李进延 Li Jinyan

Keyword(s):

Negative Curvature ◽

Influence Factors ◽

Confinement Loss ◽

Hollow Core ◽

Core Fiber

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Highly Sensitive Temperature Sensor Based on Surface Plasmon Resonance in a Liquid-filled Hollow-core Negative-curvature Fiber

Optik ◽

10.1016/j.ijleo.2021.166970 ◽

2021 ◽

pp. 166970

Author(s):

Ying Han ◽

Lin Gong ◽

Fanchao Meng ◽

Hailiang Chen ◽

Yan Wang ◽

...

Keyword(s):

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Temperature Sensor ◽

Negative Curvature ◽

Hollow Core ◽

Highly Sensitive

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Geometrical Scaling of Antiresonant Hollow-Core Fibers for Mid-Infrared Beam Delivery

Crystals ◽

10.3390/cryst11040420 ◽

2021 ◽

Vol 11 (4) ◽

pp. 420

Author(s):

Ang Deng ◽

Wonkeun Chang

Keyword(s):

Structural Parameters ◽

Transmission Band ◽

Confinement Loss ◽

Hollow Core ◽

Core Size ◽

Core Diameter ◽

Mid Infrared ◽

The Core ◽

Tubular Type ◽

Beam Delivery

We numerically investigate the effect of scaling two key structural parameters in antiresonant hollow-core fibers—dielectric wall thickness of the cladding elements and core size—in view of low-loss mid-infrared beam delivery. We demonstrate that there exists an additional resonance-like loss peak in the long-wavelength limit of the first transmission band in antiresonant hollow-core fibers. We also find that the confinement loss in tubular-type hollow-core fibers depends strongly on the core size, where the degree of the dependence varies with the cladding tube size. The loss scales with the core diameter to the power of approximately −5.4 for commonly used tubular-type hollow-core fiber designs.

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Characteristic Analysis and Structural Design of Hollow-Core Photonic Crystal Fibers with Band Gap Cladding Structures

Sensors ◽

10.3390/s21010284 ◽

2021 ◽

Vol 21 (1) ◽

pp. 284

Author(s):

Bowei Wan ◽

Lianqing Zhu ◽

Xin Ma ◽

Tianshu Li ◽

Jian Zhang

Keyword(s):

Photonic Crystal ◽

Band Gap ◽

Photonic Crystal Fibers ◽

Relative Sensitivity ◽

Confinement Loss ◽

Hollow Core ◽

Characteristic Analysis ◽

Element Analysis ◽

The Core ◽

Crystal Fibers

Due to their flexible structure and excellent optical characteristics hollow-core photonic crystal fibers (HC-PCFs) are used in many fields, such as active optical devices, communications, and optical fiber sensing. In this paper, to analyze the characteristics of HC-PCFs, we carried out finite element analysis and analyzed the design for the band gap cladding structure of HC-PCFs. First, the characteristics of HC19-1550 and HC-1550-02 in the C-band were simulated. Subsequently, the structural optimization of the seven-cell HC-1550-02 and variations in characteristics of the optimized HC-1550-02 in the wavelength range 1250–1850 nm were investigated. The simulation results revealed that the optimal number of cladding layers is eight, the optimal core radius is 1.8 times the spacing of adjacent air holes, and the optimal-relative thickness of the core quartz-ring is 2.0. In addition, the low confinement loss bandwidth of the optimized structure is 225 nm. Under the transmission bandwidth of the optimized structure, the core optical power is above 98%, the confinement loss is below 9.0 × 10−3 dB/m, the variation range of the effective mode field area does not exceed 10 μm2, and the relative sensitivity is above 0.9570. The designed sensor exhibits an ultra-high relative sensitivity and almost zero confinement loss, making it highly suitable for high-sensitivity gas or liquid sensing.

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