Browsing by Subject "Hollow-core fibers"

Now showing 1 - 5 of 5

Embargo
Enhancing polarization maintenance and spectral filtering in negative curvature hollow-core fibers
(Elsevier BV, 2023-12-09) Siddiqui, Muhammad Zain; Akosman, A. E.; Ordu, Mustafa
A new design of polarization-maintaining and spectral filtering negative curvature hollow-core fiber tailored for the telecommunication bands in the near-infrared region is presented. The optical fiber, consisting of a six-tube silica structure, incorporates vertically nested tubes anchored radially by a pole structure. By contrast, standard nested tubes in the horizontal direction form the asymmetric fiber structure, which encounters birefringence. This unique fiber design not only preserves the polarization states of light but also exhibits frequency selective transmission exclusively in the vertical direction due to the pole structure. Through fiber design optimization, a transmission loss below 0.1 dB/km for spectrally filtered wavelengths is achieved, with birefringence on the order of 10−5 within the wavelength range of 1.45 µm to 1.60 µm. These results demonstrate significant improvements in terms of birefringence, distinct loss separation between horizontally and vertically polarized states, and a reduced number of spectrally filtered wavelengths compared to previously reported findings. The proposed fiber design holds untapped potential for applications requiring selective transmissions with specific polarization.
Open Access
Exploration of hybrid cladding elements in chalcogenide hollow-core fibers for low-loss mid-infrared transmission
(Elsevier GmbH, 2021-10-27) Khan, Asfandyar; Ordu, Mustafa
Optical losses of chalcogenide negative curvature hollow-core fibers with hybrid cladding elements were numerically investigated in this study. Microstructured cladding formed by the combination of tubular and elliptical elements was designed for low-loss operation in the mid-infrared spectrum. A confinement loss value of 0.287 dB/km was calculated for the proposed ellipse-nested tubular negative curvature fiber with optimized design parameters at 10.6 µm. Achieved confinement losses with the proposed design are several orders of magnitude lower than the tubular/elliptical negative curvature fibers in the targeted spectrum. The effect of the material absorption to the total fiber losses was also investigated along with the confinement losses. Suppression on the higher-order modes by the proposed fiber was numerically observed. The negative curvature fibers are promising for the low-loss guidance of CO2 lasers that are widely used for various applications spanning from material processing to surgery.
Open Access
Hollow-core optical fiber with eight-pointed star cladding structure for low-loss transmission in telecom bands
(Scientific and Technical Research Council of Turkey - TUBITAK,Turkiye Bilimsel ve Teknik Arastirma Kurumu, 2021-04-29) Ordu, Mustafa
In this study, a novel negative curvature hollow-core fiber is proposed for low-loss transmission in the near-infrared region. We numerically investigate the effect of the cladding structure, which is formed of concentrically interlaced squares, to the confinement losses using the finite element modelling. The design has eight cladding tubes with nested elements placed to the outer edge of the tubes. The confinement losses of the interlaced square core fiber is calculated as low as 0.12 dB/km in the range of 1.3 to 1.65 µm. The loss profile of the noncircular core design is comparable with the circular cores, and have improved transmission performance at 1.55 µm. The proposed design can have numerous application areas such as data transmission, nonlinear optics and biochemical sensing.
Embargo
Mid-infrared negative curvature hollow-core fiber with elliptically nested tubular structure
(Elsevier B.V., 2022-12-24) Khan, Asfandyar; Ordu, Mustafa
Arsenic triselenide chalcogenide negative curvature hollow-core fiber with ellipse-nested tubular cladding elements was numerically presented for the low-loss light guidance in the mid-infrared region. Confinement and total losses were calculated for the fiber with a five-tube design as low as 0.34 dB/km and 4.55 dB/km at 10.6μm, respectively. The single-mode light guidance characteristic of the proposed design was investigated, and a strong suppression on the higher-order modes shows that the fiber design favors the light guidance with the fundamental mode. A dispersion control study was carried out to optimize the primary design parameters to shift the zero-dispersion wavelength close to 10.6μm. The bending loss performance of the proposed design was analyzed in the targeted spectrum. The proposed negative curvature hollow-core fiber could be potentially used in low-loss guidance for high-power lasers and could also be utilized for several other applications, such as surgery and drug delivery in the mid-IR spectrum. © 2022 Elsevier B.V.
Open Access
Nested compound negative curvature hollow-core fiber for single-mode operation in the infrared region
(Elsevier, 2021-06-10) Akosman, A. E.; Ordu, Mustafa
In this study, a novel tubular hollow-core fiber design with extended cladding structures aiming low transmission losses and dominant single-mode guidance in the infrared region is proposed. The fiber parameters are optimized to achieve low-loss operation at the target wavelength of , at which the emission spectrum of thulium-doped fiber lasers are centered. The confinement loss of the fundamental mode is found to be less than 0.02 dB/km in the near- and mid-infrared region, which makes the proposed design a strong alternative for conventional step-index silica optical fibers. Strong suppression of the higher order modes, and low bending sensitivity are also observed in the proposed design. The proposed fiber shows promising results to achieve low-loss transmission in the infrared spectrum.