Birefringent Fiber Research Articles

Polarization maintaining, normal-dispersion silica fiber for dispersion compensation in ultrafast erbium and thulium-doped fiber lasers

We present a highly birefringent silica fiber with normal dispersion up to 2334 nm, designed to control a net-cavity dispersion of pulsed fiber lasers at different wavelengths. The fiber is characterized by a large normal dispersion, slowly growing from -87 ps/nm/km at 1200 nm to -42 ps/nm/km at 2000nm, and high phase birefringence exceeding 1.9 × 10−4 in this spectral range which ensures a polarization extinction ratio as high as 28 dB for a 1 m long fiber section. The industrially fabricated fiber was examined in two all-polarization-maintaining mode-locked fiber oscillators operating at central wavelengths of 1560 nm and 1980nm. We confirmed the ability to manage the dispersion of the oscillators, which worked in both anomalous and normal dispersion, maintaining stable mode-locking. Employing the developed fiber with normal dispersion has resulted in a broadening of spectral full width at half maximum from 7.8 to 44.3 nm and from 5.5 to 25.8 nm for the erbium and thulium lasers, respectively. The ability to support operation in the range of tens of MHz allows for the application of the developed laser sources in systems reducing the repetition rate via e.g. pulse picking.

Non‐Markovian Dynamics in Fiber Delay‐Line Buffers

AbstractThe non‐Markovian effect is studied on a two‐photon polarization entangled state, in which one photon from the pair is stored in a fiber delay‐line buffer. A model of a photonic qubit coupled to fiber birefringence and a fiber reservoir representing the environment is proposed. Analytically, a non‐Markovian probability function is derived for the buffered photon and its paired photon. To verify the probability function, full quantum state tomography of the photon pairs is performed. The probability function fits well with the experimental data and physical values. These results indicate that the quantum system operates slightly above the threshold for a non‐Markovian transition. We observe a unique polarization dynamic of the buffered photon. Measures of quantum mutual information are further exploited to study the quantumness of the photon pairs. Werner's well‐known separability criterion occurs at a buffer time of about 0.9 ms. These results imply that quantum discord can surpass Werner's criterion, and hence, quantum bi‐partite correlation can exist for buffer times greater than 0.9 ms.

Sub-pico-second chirped optical solitons in birefringent fibers for space--time fractional Kaup-Newell equation

The present work is devoted to investigate the chirped bright and dark optical solitons of fractional Kaup-Newell equation (KNE) in birefringent fibers. The study is carried out analytically by the traveling wave hypothesis with the conformable derivative which reduces the governing model to an ordinary differential equation (ODE). The obtained equation is handled with the aid of an exotic integration scheme that utilizes the Jacobi elliptic equation in the form of a first-order nonlinear ODE with three-degree terms. Taking the modulus of Jacobi elliptic function to unity, distinct types of bright and dark optical solitons are derived with their corresponding chirping. The fractional order derivative is noted to have a significant influence on the pulse propagation. Additionally, the nonlinearity amount causes also marked variations in the amplitude and width of solitons. The modulation instability of the KNE is reported by implementing the linear stability analysis which confirms that all solutions are stable. The revealed results can be capitalized in improving the relevant physical and engineering applications in the field of birefringent fiber.

Quantum-Enhanced Strain and Curvature Sensing Based on a Birefringent Fiber Sagnac Interferometer

Quantum-Enhanced Strain and Curvature Sensing Based on a Birefringent Fiber Sagnac Interferometer

Highly birefringent and low loss anti-resonant hollow-core fiber with stadium-shaped nested structure

Abstract We propose a stadium-shaped nested anti-resonant hollow-core fiber (SSAF), designed to enable high birefringence and low loss in the near-infrared bands. Numerical investigation and simulation for variations in parameters of stadium-shaped nested structure are conducted, and confinement loss (CL) is reduced by parameters optimization while birefringence of 10−4 is maintained. With optimized SSAF structure, the birefringence and CL are improved to 1.39 × 10−4 and 26.5 dB km−1 at 1.38 µm, 1.28 × 10−4 and 2.64 dB km−1 at 1.55 µm, respectively. Meanwhile, it exhibits favorable single-mode characteristics and achieves a high high-order mode extinction ratio of up to 103, and the superior bending resistance characteristics are validated. Our work offers valuable guidance for designing and optimizing highly birefringent SSAF anti-resonant fiber, and the proposed SSAF has great application potential in polarization-dependent transmission and interferometric fiber gyroscope.

Optical solitons in cubic–quartic form within birefringent fibers through the Schrödinger–Hirota equation addressing cubic–quintic nonlinearity

In this paper, we study the Schrödinger–Hirota equation in birefringent fibers incorporating cubic–quartic dispersion. The model studied comes with a cubic–quintic nonlinear structure. The governing model introduced in this study is novel and original, and the obtained solitons have not been reported before. The Schrödinger–Hirota equation is an important modified structure within the higher-order NLSE that garnered significant attention in the fields of mathematics and physics, especially in the context of the transmission of solitons in water waves and optical fibers. To investigate optical solitons for this model, three widely applied in various research studies are implemented for our governing model. These methods are the Unified Riccati expansion method, the addendum to Kudryashov’s method, and the addendum to the modified Sub-ODE method. A variety of solutions have emerged with this governing model, including bright, dark, singular solitons and the hybrid of these solitons. Also, Jacobi and Weierstrass doubly periodic-type solutions are recovered, which, with selected parameters, these solutions give solitons. Furthermore, for more illustration of the obtained solutions, a detailed discussion with a graphical presentation is presented.

Visualization of the Scleral Structure Changes at Various Stages of Eyes With Myopic Maculopathy Using Polarization-Sensitive OCT

PurposeTo observe the detailed structures of the inner and outer sclera at various stages of myopic maculopathy using polarization-sensitive optical coherence tomography (PS-OCT). MethodsA PS-OCT system was developed for imaging the posterior eye using a swept laser. Data from highly myopic patients who underwent PS-OCT examination between May and June 2019 were used to generate birefringence images (showing scleral fiber density), optic axis images (visualizing the orientation of scleral fibers), and streamline images (providing 3D reconstructions to visualize scleral fiber stream). ResultsA total of 89 eyes of 65 patients with high myopia were examined and analyzed for this study. The mean axial length was 30.4 ± 1.8mm. In highly myopic eyes with a thin choroid, PS-OCT visualized the detailed structure of the sclera, and the optic axis images differentiated the direction of the inner and outer scleral fibers. In the optic axis and streamline images, the inner layer of the sclera contained radial fibers extending from the optic disc. In contrast, the outer layer of the sclera contained vertical fibers. With the progression of myopia, highly birefringent fibers first disappear in the inner scleral layer, followed by thinning of the inner layer itself. Subsequently, in the outer scleral layer, the number of highly birefringent fibers decreased. As myopic maculopathy worsened, the inner and outer layers of the sclera disintegrated. ConclusionsPS-OCT is useful for observing the structures of the inner and outer sclera in various conditions of myopic maculopathy.

Elliptical birefringence model for highly efficient study of SOP and DOP in complicated birefringent fiber

Optical chirality has recently let to many novel prospects and applications and this phenomenon also exists in twisting linear birefringent fiber. However, it has not been investigated when the birefringence is non-uniform, namely, both the spinning rate and linear birefringence vary along the fiber axis. Additionally, this non-uniformity brings dissatisfaction in terms of computational efficiency when using traditional methodologies, such as the coupled mode theory and the cascaded linear phase delayer matrix model. In order to study this kind of complicated birefringent fiber (CBF), this work introduces an innovative solution to this issue: the elliptical phase delayer model, specifically designed to analyze situations where the optical fiber experiences arbitrary spinning. The derivation of this model employs the Jones matrix, and its validity and computational efficiency are verified through numerical calculations. Furthermore, this work explores the State of Polarization (SOP) of CBF using the proposed model. It also investigates the Degree of Polarization (DOP) of the output light wave, which is indicative of the depolarization effect due to spinning. This study presents an elliptical phase delayer model that offers an efficient means of calculating the SOP and DOP of CBF, and is also applicable to other spun optical structures.

Broadband high birefringence and single-polarization hollow-core anti-resonant fibers with an elliptical-like core

Due to the light-guiding mechanism of hollow-core anti-resonant fibers (HC-ARFs), the low overlap between core modes and anti-resonant layers poses a challenge in achieving high birefringence. To address this issue, we propose three high-birefringence HC-ARFs with an elliptical core and varying cladding compositions and conduct a detailed optimization and analysis for structure (c). Simulation results demonstrate that structure (a) and structure (b) provide high birefringence, broadband, and low-loss transmission properties. Specifically, structure (a) achieves a birefringence greater than 1.3×10−4 over a 680 nm wavelength range, and structure (b) achieves a birefringence greater than 1.6×10−4 over a 580 nm wavelength range, both maintaining fundamental mode (FM) loss below 1 dB/m. Structure (c) enhances birefringence by an order of magnitude and offers excellent single-polarization properties by introducing high-refractive-index material. At 1.55μm, structure (c) achieves a birefringence of 0.98×10−3, with a low FM loss for x-polarization of 0.01 dB/m and a polarization extinction ratio (PER) of 57450. Additionally, structure (c) exhibits low bend loss in the x-direction, with only 0.06 dB/m for a bend radius of 6 cm.

Turning four-wave mixing on and off in elliptically birefringent fibers via narrow frequency detuning.

Controlling four-wave mixing (FWM) is vital for several applications, including fiber optical communication, optical signal processing, optical amplification, and frequency generation. This paper presents a novel, to our knowledge, approach to control unidirectional FWM in elliptically birefringent fibers. By leveraging the frequency-dependent polarization eigenmodes of these fibers and detuning the optical frequency of one of the pump fields by a few megahertz, we can turn the FWM interaction on and off, thus controlling the generation of signal and idler fields. Moreover, this approach allows us to turn off the FWM interaction at any desired frequency, enabling all-optical switching and narrowband filtering applications.

Design and error analysis of simple terahertz high birefringence microstructured fiber

Abstract High birefringence fibers are significant in the terahertz technology field, serving as waveguides for terahertz transmission. They are applicable in various fields such as communication, imaging. Integrating metal microstructures into polymer microstructured optical fibers can effectively modulate the transmission characteristics of the fiber, enhancing birefringence and reducing loss, thereby achieving better performance compared to traditional single-material fibers. This paper presents a structurally simple terahertz high birefringence microstructured fiber, where the introduction of gold microstructures enhances the birefringence of fiber, with a maximum birefringence of up to 1.089 × 10−2. We also discuss several manufacturing errors that may occur during the fiber fabrication process. The results indicate that the designed fiber exhibits significant manufacturing tolerance. Variations in the thickness and angle of the gold microstructures, as well as the angular offset of the elliptical cladding wall, peak-to-valley errors, and changes in the aspect ratio of the elliptical tube, have relatively minor effects on the overall transmission performance. The research findings provide insights for designing subsequent high birefringence terahertz fibers, thereby propelling advancements in this field. They offer a theoretical basis for the preparation of related microstructured fiber structures and provide valuable understanding for optimizing fiber manufacturing processes.

Effects of white noise on straddle and soliton dynamics in birefringent fibers using the novel Kaup-Newell equation approach

Effects of white noise on straddle and soliton dynamics in birefringent fibers using the novel Kaup-Newell equation approach

The dynamic behaviors between double-hump solitons in birefringent fibers

In this paper, we research the fractional coupled Hirota equations with variable coefficients describing the collisions of two waves in deep oceans and the propagation of ultrashort light pulses in birefringent fibers and successfully acquire the double-hump one-soliton, two-solitons and N-solitons solutions via the Hirota bilinear method. At the same time, the Bäcklund transformation and the corresponding soliton solutions are also obtained. Based on the precise forms of the solitons solutions, we gain double-hump solitons images with different shapes including U-shape, V-shape and wave-type by assigning proper functions to the group velocity dispersion and the third-order dispersion and analyze the interaction dynamics of double-hump solitons. It is worth noting that the Hirota bilinear operators involved here are fractional rather than integer, which has never appeared in previous literatures.

Stripe Soliton in All‐Fiber Lasers

AbstractStripe solitons (SSs), the special localized wavepackets exhibiting periodic modulations, are identified in condensed matter physics and nonlinear science. Here, giant‐chirp and chirp‐free SSs in all‐fiber lasers are demonstrated composed of single‐mode fiber and polarization‐maintaining fiber. The chirp property of SSs depends on the cavity dispersion while the stripe period relies on the fiber birefringence. Theoretical and numerical results coincide with experimental findings, revealing that the filtering and frequency shift of two vector modes is governed by the mode coupling related to birefringence and the nonlinear coupling induced by the phase modulation, respectively, which disrupts their complementarity and ultimately leads to modulation of the overall spectrum. With the aid of the saturable absorption and cross‐phase modulation effects, the multi‐color pulses synergistically overlap, giving rise to the unique SSs. These results present a simple approach for generating chirp‐controllable SSs in all‐fiber lasers, which is crucial for applications in difference frequency generation and soliton physics.

Highly birefringent hexagonal porous core photonic crystal fiber for polarization maintaining integrated THz-photonics applications

Highly birefringent hexagonal porous core photonic crystal fiber for polarization maintaining integrated THz-photonics applications

New Coupled Optical Solitons to Birefringent Fibers for Complex Ginzburg–Landau Equations with Hamiltonian Perturbations and Kerr Law Nonlinearity

In this study, we use an analytical method tailored for the in-depth exploration of coupled nonlinear partial differential equations (NLPDEs), with a primary focus on the dynamics of solitons. Traditional methods are quite effective for solving individual nonlinear partial differential equations (NLPDEs). However, their performance diminishes notably when addressing systems of coupled NLPDEs. This decline in effectiveness is mainly due to the complex interaction terms that arise in these coupled systems. Commonly, researchers have attempted to simplify coupled NLPDEs into single equations by imposing proportional relationships between various solutions. Unfortunately, this simplification often leads to a significant deviation from the true physical phenomena that these equations aim to describe. Our approach is distinctively advantageous in its straightforwardness and precision, offering a clearer and more insightful analytical perspective for examining coupled NLPDEs. It is capable of concurrently facilitating the propagation of different soliton types in two distinct systems through a single process. It also supports the spontaneous emergence of similar solitons in both systems with minimal restrictions. It has been extensively used to investigate a wide array of new coupled progressive solitons in birefringent fibers, specifically for complex Ginzburg–Landau Equations (CGLEs) involving Hamiltonian perturbations and Kerr law nonlinearity. The resulting solitons, with comprehensive 2D and 3D visualizations, showcase a variety of coupled soliton configurations, including several that are unprecedented in the field. This innovative approach not only addresses a significant gap in existing methodologies but also broadens the horizons for future research in optical communications and related disciplines.

Picosecond laser with Yb-doped tapered low birefringent double clad fiber

Abstract In this study, we present results of development fiber picosecond laser by using an active ytterbium tapered double clad optical fiber with mode field diameter of 35 μm and low intrinsic birefringence (1.45 * 10−8 rad m−1). We have demonstrated 1040 nm/50 ps optical source with tunable repetition rate (within range of 1–20 MHz) and an average power of 160 W (peak power 160 kW, 8 μJ per pulse) delivering Gaussian beam with excellent quality (M 2 ∼ 1.11/1.22).

Optical soliton solutions in birefringent fibers with multiplicative white noise: an analysis for the perturbed Chen–Lee–Liu model

Optical soliton solutions in birefringent fibers with multiplicative white noise: an analysis for the perturbed Chen–Lee–Liu model

Analyzing the influence of multiplicative white noise on optical solitons in birefringent fibers through the perturbed Gerdjikov–Ivanov model

Analyzing the influence of multiplicative white noise on optical solitons in birefringent fibers through the perturbed Gerdjikov–Ivanov model

Schrödinger-Hirota equation in birefringent fibers with cubic-quantic nonlinearity and multiplicative white noise in the ito sense: Nucci’s reductions and soliton solutions

This paper explores innovative solutions for the Stochastic Schrödinger-Hirota equation within the context of birefringent fibers with cubic-quintic nonlinearity, emphasizing incorporating multiplicative white noise in the Itô sense. Leveraging the Nucci reduction method, the study focuses on obtaining exact solutions, shedding light on the intricate interplay between quantum mechanics and stochastic processes. The Nucci reduction method is a powerful tool to facilitate the derivation of precise solutions, showcasing its efficacy in unravelling complex mathematical structures and providing valuable insights into the behaviour of quantum systems under the influence of diverse parameters. In addition, two effective and convenient procedures are employed to extract bright, dark, and unique soliton solutions, as well as their combination. Exploring these solutions contributes to a deeper understanding of the equation’s dynamics, particularly in real-world applications such as quantum optics and condensed matter physics. Additionally, this study incorporates graphical depictions of specific solutions to demonstrate the effect of white noise on solitons visually.