Birefringent Fiber Research Articles

Effect of draw temperature and flame polishing on birefringence of silica glass fiber

AbstractRecently developed methods for high resolution birefringence measurement have been applied to distinguish between the surface and interior birefringence of silica glass fibers as a function of drawing temperature and initial surface condition for two types of silica glass with different water contents. Fibers were drawn in a water‐free argon environment using graphite heating elements. It was found that fibers drawn at lower temperatures resulted in greater, interior birefringence, in agreement with previous reports. Additionally, it was found that in the case of low‐water silica glass, flame polishing via oxygen–hydrogen mixture and drawn into fibers at lower temperature resulted in significant surface compressive stress upon drawing. This compressive stress may be the result of surface stress relaxation in silica glass that occurs in the presence of water during fiber drawing. In silica glass that contains greater internal hydroxyl impurity concentrations, the interior birefringence as well as the surface stress relaxation was significantly reduced under the same fiber drawing conditions. Characterization of such stress responses provides insight into the effects of common processing techniques as well as impresses the significance of preform processing for consistent fiber production.

A Prototype for a Passive Resonant Interferometric Fiber Optic Gyroscope with a 3 × 3 Directional Coupler.

Reducing the dimensions of optical gyroscopes is a crucial task and resonant fiber optic gyroscopes are promising candidates for its solution. The paper presents a prototype of a miniature resonant interferometric gyroscope of a strategic accuracy class. Due to the use of passive optical elements in this gyroscope, it has a great potential for miniaturization, alongside a low production cost and ease of implementation, since it does not require many feedback loops. The presented prototype shows results on a zero instability of 20°/h and an angle random walk of 0.16°/√h. A theoretical model explaining the nature of the multipath interference of resonant spectra and establishing the relationship between the resonator parameters and the output parameters of the presented prototype is proposed. The results predicted are in agreement with the experimental data. The prototype gyroscope demonstrates a scale factor instability and a change in the average signal level, which is due to the presence of polarization non-reciprocity, occurring due to the induced birefringence in the single-mode fiber of the contour. This problem requires further investigation to be performed.

Thermal Sensitivity of Birefringence in Polarization-Maintaining Hollow-Core Photonic Bandgap Fibers

Polarization-maintaining (PM) fiber is the core sensitive component of a fiber optic gyroscope (FOG); its birefringence temperature stability is crucial for maintaining accuracy. Here, we systematically investigated the structural thermal deformation and the resulting birefringence variation in typical PM hollow-core photonic bandgap fibers (HC-PBGFs) for FOG according to varying fiber structure parameters. To verify the application potential of PM HC-PBGFs in FOG, we compared the thermal sensitivity of birefringence (TSB) with that of the commonly used Panda PM fiber, which was tested to 5.07 × 10−5/100 °C. For rhombic-core fibers, the TSB was determined by the structure of the cladding and could be tuned as low as low as 10−7/100 °C, two orders of magnitude smaller than that of the panda PM fibers. For hexagonal-core fibers, the birefringence variation depended mainly on the drift of the surface modes (SMs) caused by the deformation of the core. A slight drift in SMs could cause a dramatic birefringence variation in hexagonal-core fiber, and the TSB could be as high as 10−4/100 °C, much higher than that of panda PM fiber. This study lays the foundation for the development of high birefringence temperature-stable HC-PBGFs and their applications in FOG.

Non-local polarization alignment and control in fibers using feedback from correlated measurements of entangled photons.

Quantum measurements that use the entangled photons' polarization to encode quantum information require calibration and alignment of the measurement bases between spatially separate observers. Because of the changing birefringence in optical fibers arising from temperature fluctuations or external mechanical vibrations, the polarization state at the end of a fiber channel is unpredictable and time-varying. Polarization tracking and stabilization methods originally developed for classical optical communications cannot be applied to polarization-entangled photons, where the separately detected photons are statistically unpolarized, yet quantum mechanically correlated. We report here a fast method for automatic alignment and dynamic tracking of the polarization measurement bases between spatially separated detectors. The system uses the Nelder-Mead simplex method to minimize the observed coincidence rate between non-locally measured entangled photon pairs, without relying on classical wavelength-multiplexed pilot tones or temporally interleaved polarized photons. Alignment and control is demonstrated in a 7.1 km deployed fiber loop as well as in a controlled drifting scenario.

Stochastic Solitons in Birefringent Fibers for Biswas–Arshed Equation with Multiplicative White Noise via Itô Calculus by Modified Extended Mapping Method

Stochastic partial differential equations have wide applications in various fields of science and engineering. This paper addresses the optical stochastic solitons and other exact stochastic solutions through birefringent fibers for the Biswas–Arshed equation with multiplicative white noise using the modified extended mapping method. This model contains many kinds of soliton solutions, which are always symmetric or anti-symmetric in space. Stochastic bright soliton solutions, stochastic dark soliton solutions, stochastic combo bright–dark soliton solutions, stochastic combo singular-bright soliton solutions, stochastic singular soliton solutions, stochastic periodic solutions, stochastic rational solutions, stochastic Weierstrass elliptic doubly periodic solutions, and stochastic Jacobi elliptic function solutions are extracted. The constraints on the parameters are considered to guarantee the existence of these stochastic solutions. Furthermore, some of the selected solutions are described graphically to demonstrate the physical nature of the obtained solutions.

Multi-vector with nonlocal and non-singular kernel ultrashort optical solitons pulses waves in birefringent fibers

This research study investigates different structures and novel solitary wave solutions of to the nonlinear fractional Lakshmanan–Porsezian–Daniel equation LPDE. The investigated model describes the dynamical and physical properties of the wave pulse in birefringent fibers which incorporates two vector solitons. A new fractional derivative with nonlocal and non-singular kernel is used to convert the model’s fractional form into ordinary differential equation with an integer order. Three recent computational schemes (novel generalized Kudryashov (NKud) method, Khater II (Khat II) method, Sardar Sub-equation (SSE) method) are employed to construct some novel solitary wave solution of the LPDE in various structures. The outcome results are visually demonstrated through some distinct graphs in 2-, 3-dimensional, density, and polar plots to explain some novel properties of the investigated model. Mathematica 13.1 checks all inputs and outputs against the original model for further confidence.

Modulation instability gain and wave patterns in birefringent fibers induced by coupled nonlinear Schrödinger equation

In this work, we studied the behavior of the modulation instability (MI) growth rate and modulated wave (MW) bright and dark-soliton in nonlinear optical fibers (OFs) where both birefringence and four-wave mixing (4WM) terms are employed. We have shown the effects of the 4WM and the group velocity dispersion (GVD) on the MI gain and MI bands as well as on the MWs patterns. For certain conditions on the coupled nonlinear Schrödinger equation (CNLSE) parameters, we exhibited stable and unstable zones of the MI. More precisely, in a normal dispersion regime, we shown how the variation of 4WM can generate additional sides lobes and consequently the formation of new MI bands. Furthermore, it is observed that when the coupling coefficient (CC) increases, its effects could reduce the stability zones by increasing strongly the number of sides lobes in a normal dispersion regime. To seek the behavior of the MWs patterns, we used numerical investigation (NI). From these results, it has been observed the propagation of the MW bright-soliton and dark-soliton with the effects of the 4WM. We noticed that the MWs patterns can preserve high energy on the peak and keep constant its shapes in birefringent OFs. These results show that the 4WM and the GVD behave as being energy sources for MI and MWs. Our finding can help to manufacture OF tools and could open the way for the use of the 4WM and cross-phase modulation (XPM) to generate MI bands and long-live temporal MWs patterns.

New diverse types of soliton solutions to the Radhakrishnan-Kundu-Lakshmanan equation

<abstract> <p>The main purpose of this study was to produce abundant new types of soliton solutions for the Radhakrishnan-Kundu-Lakshmanan equation that represents unstable optical solitons that emerge from optical propagations through the use of birefringent fibers. These new types of soliton solutions have behaviors that are bright, dark, W-shaped, M-shaped, periodic trigonometric, and hyperbolic and were not realized before by any other method. These new forms have been detected by using four different techniques, which are, the extended simple equation method, the Paul-Painlevé approach method, the Ricatti-Bernoulli-sub ODE, and the solitary wave ansatz method. These new solitons will be arranged to create a soliton catalog with new impressive behaviors and they will contribute to future studies not only for this model but also for the optical propagations through birefringent fiber.</p> </abstract>

Optical solitons and complexitons for the concatenation model in birefringent fibers

Optical solitons and complexitons for the concatenation model in birefringent fibers

Intermodal-vectorial four-wave mixing processes involving LP01, LP11, LP02 and LP21 modes of birefringent fibers

We present the complete (analytical, numerical and experimental) analysis of intermodal-vectorial four-wave mixings proccesses in birefringent fibers. We analyze phase-matching condition and overlap coeffi-cients to indicate possible processes. Then, we demonstrate multiple four-wave mixing processes in LP01 and LP11 modes numerically and experimentally. Finally, we extend theoretical analysis to account higher-order modes: LP02 and LP21.

Histomorphological evaluation of stromal collagen in canine mammary tumours: A study using picrosirius red stain and polarizing microscopy

Mammary gland tumours are considered as the most common neoplasms in sexually intact female dogs. Incidence of mammary tumours, especially the malignant ones are found to be rare in dogs younger than five years of age. Latest reports indicate that more than 75 per cent of canine mammary tumours (CMTs) are of malignant type. Recent research has demonstrated that in breast cancer, apart from changes in the parenchyma, major modifications also occur in the stroma or tumour microenvironment, which surrounds the neoplastic cells and these changes are now understood to be crucial factors in the onset and progression of tumour. The tumour microenvironment consists of multiple cell types such as fibroblasts, leukocytes, adipocytes, myoepithelial cells, endothelial cells and the extra cellular matrix (ECM). Numerous studies have indicated that the primary protein in the ECM, collagen, has the potential to give physical, biochemical, and biomechanical impulses to both tumour and non-tumour cells, thus regulating the growth and spread of cancer. The current study employed special staining using picrosirius red to demonstrate the stromal collagen in CMTs and utilised polarised microscopy to analyse the birefringence of collagen fibres in tumours. Picrosirius red staining for evaluation of alterations in stromal collagen fibres was identified to be highly efficient in determining the prognosis of CMTs.

Temperature-independent multi-parameter sensor based on polarization maintaining fiber Bragg grating

Dynamic multi-parameter detection is of great significance in predicting fatigue damage to structures such as tunnels, bridges, and pipelines. Developing a high-sensitivity, environmentally friendly, low-cost, and easy-to-operate multi-parameter dynamic detection technology has always been the goal of the industry. The polarization-maintaining fiber Bragg grating (PM-FBG) has a special grating structure composed of fiber Bragg grating (FBG) directly written into high birefringence and polarization-maintaining fiber, and it supports two distinct polarization eigenmodes with two effective refractive indices. The PM-FBG couples the light beams polarized along the two principal axes corresponding to slow axis and fast axis at two different Bragg wavelengths. The two peaks of PM-FBG have different responses to external changes, which may be used to solve the cross-sensitivity problem of FBG sensor and realize the simultaneous multi-parameter measurement of the temperature, longitudinal strain, transverse strain, or twist. In order to solve the problems of complex structure and principle and high production cost of FBG-based multi-parameter sensors, a novel multi-parameter fiber-optic sensor with high sensitivity and temperature independence is designed based on PM-FBG in this work. The PM-FBG sensor proposed can simultaneously measure the changes of displacement and twist in two vertical directions at a certain point and has the function of temperature self-compensation. The external structure of the sensor is fabricated by using three-dimensional printing technology through the fused deposition method and the raw material for creating different components through using polylactic acid. Experimental results show that the fast axis and slow axis of the sensor have different temperature responses, with linear sensitivities of 11.4 pm/℃ and 10.6 pm/℃, respectively, and the temperature compensation coefficient and average torsional sensitivity of the PM-FBG sensor are 0.8 pm/℃ and 0.20 dB/(°), respectively. The fast axis and slow axis of the PM-FBG sensor have the same response to displacement, with a sensitivity of 31.5 pm/mm and an adjustable range of 0–20 mm. The sensitivity to displacement, torsion, and temperature sensitivities of the sensor are all superior over those of commercial FBG sensors. By changing the temperature field around the sensor, its displacement- and torsion-sensing performances are not affected, thereby realizing the temperature self-compensation. Consequently, the proposed sensor has potential applications in the multi-parameter dynamic detection due to its simple structure, high sensitivity, good mechanical strength, and low cost.

Approximated exponential integrators for the stochastic Manakov equation

This article presents and analyzes an approximated exponential integrator for the (inhomogeneous) stochastic Manakov system. This system of SPDE occurs in the study of pulse propagation in randomly birefringent optical fibers. For a globally Lipschitz-continuous nonlinearity, we prove that the strong order of the time integrator is $ 1/2 $. This is then used to prove that the approximated exponential integrator has convergence order $ 1/2 $ in probability and almost sure order $ 1/2^{-} $, in the case of the cubic nonlinear coupling which is relevant in optical fibers. Finally, we present several numerical experiments in order to support our theoretical findings and to illustrate the efficiency of the approximated exponential integrator as well as a modified version of it.

Time-division multiplexing of Mbit/s data-packets within Gbit/s data sequences through nonlinear temporal focusing

In this work, we report on an all-optical, real-time, nonlinear temporal compression technique based on a counter-propagating degenerate four-wave mixing interaction in birefringent optical fibres. As a proof-of-concept, we demonstrate the extreme temporal focusing and interleaving of a 10-Mbit/s data packet into a 10-Gbit/s data sequence, with record temporal compression factors ranging from 3 to 4 orders of magnitude and including non-trivial on-demand time-reversal capabilities. Our approach is scalable to different photonic platforms and offers great promise for ultrafast arbitrary optical waveform generation and related applications, while enabling the compression of THz-bandwidth optical signals from low-cost, low-bandwidth optical waveform generators.

Birefringent, low loss, and broadband semi-tube anti-resonant hollow-core fiber.

We report on the design, fabrication, and characterization of a low-loss birefringent semi-tube anti-resonant hollow-core fiber (AR-HCF). By optimizing the structure design and the stack-and-draw fabrication technique, a transmission loss of 4.8 dB/km at 1522 nm, a <10dB/km bandwidth of 154 nm, and a phase birefringence of 1.8 × 10-5 are demonstrated. This achieved loss is more than one order of magnitude lower than the previously reported birefringent AR-HCF and the bandwidth is one order of magnitude broader than the reported birefringent photonic bandgap hollow-core fiber (PBG-HCF) with the same loss level. The polarization extinction ratio (PER) reaches the ∼20 dB level in a 90m-long fiber under >25cm bending radius. Combined with the single mode and low dispersion features, the developed semi-tube AR-HCF may find a variety of applications in frequency metrology, interferometric fiber gyroscopes, and long-baseline stellar interferometry.

Study of Sasa–Satsuma dynamical system for Kuznetsov–Ma and generalized breathers, lump, periodic and rogue wave solutions

Different analytical solutions for Sasa–Satsuma model equation (SSM) in birefringent fibers are investigated in this research like rogue wave, lump, multi-wave, multiple breather solutions, periodic wave, breather lump, periodic cross kink, periodic cross lump, and lump with one and two kinks. By examining the SSM, we can compute the important relationship between the interaction between kink, lump with periodic wave and a variety of exact solutions. To see the behavior of effective waves, we illustrate the pictorial depiction for our retrieve analytical solutions.

Ultra-short optical pulses in a birefringent fiber via a generalized coupled Hirota system with the singular manifold and symbolic computation

Nonlinear electrodynamic studies are currently interesting, while fiber transmission is superior in the high-bit-rate long-distance communications. Hereby, for certain ultra-short optical pulses in a birefringent fiber, with the singular manifold and symbolic computation, we investigate a generalized coupled Hirota system by way of constructing one auto-Bäcklund transformation with some analytic solutions. Our results depend upon the optical-fiber coefficients in the system.

Zastosowanie światłowodowego interferometru różnicowego w pomiarach natężenia prądu elektrycznego

The article presents an electric current sensor built of a fiber-optic differential interferometer using the Faraday effect in a single-mode fiber. It was applied to measure current waveforms with large amplitudes and mains frequency. The optical sensor does not introduce additional resistance and inductance into the measured circuit, which is a desirable phenomenon in this type of measurements. The magnetosensitive element is an optical fiber coil made of a quartz single-mode telecommunications fiber. The optical fiber, in which the core is twisted around its axis, is characterized by a small influence of disturbing quantities, i.e., mechanical vibrations and pressure changes, on the working of the differential interferometer by inducing linear birefringence in the glass fiber. The methods of elimination of the quantities influencing the operation of the optical fiber current sensor were proposed by reducing the linear birefringence induced in the optical fiber from these quantities. The dependence of the normalized light intensity was plotted. The results of experimental research on a design solution of a differential interferometer based on the Faraday effect, operating at a wavelength of 1550 nm, are presented. The sensor was used for measurements of sinusoidal current with a frequency of 50 Hz and amplitudes ranging 100–1500 A. The uncertainty of measurement of the electric current amplitude was determined in the range of the measured values, which was estimated at no more than 1.5 %.

Optical Wave Phenomena in Birefringent Fibers Described by Space-Time Fractional Cubic-Quartic Nonlinear Schrödinger Equation with the Sense of Beta and Conformable Derivative

The work explores the optical wave solutions along with their graphical representations by proposing the coupled spatial-temporal fractional cubic-quartic nonlinear Schrödinger equation with the sense of two fractal derivatives (beta and conformable derivative) and Kerr law nonlinearity for birefringent fibers. The new extended direct algebraic method for the first time is implemented to achieve this goal. Many optical solutions are listed along with their existence criteria. Based on the existence criteria, the cubic-quartic bright, and singular optical soliton, periodic pulse, and rouge wave profiles are supported in birefringent fibers with the influence of both beta and conformable derivative parameter.

All-Fiber Waveplate Made of Helically Wound Spun Highly Birefringent Optical Fiber

Waveplates are elements that are widely used in the optical system for polarization transformation. In the fiber optical system, it is highly desired to utilize waveplates in the all-fiber form with minimum insertion loss and stable performance. In this paper, we propose an all-fiber waveplate that is made of the helically wound spun highly birefringent (SHB) optical fiber. To function as waveplates, the torsion of the helix should be equal to the inherent polarization rotation of the SHB fiber so that the geometric rotation can match the inherent polarization rotation. Therefore, the phase difference between two orthogonal components of the incident polarized light can increase almost linearly with the fiber length. Because the SHB fiber is insensitive to external perturbations, the proposed waveplate can provide a definite and stable polarization transformation. We develop a model based on the perturbation theory to characterize the polarization evolution of the helically wound SHB fiber. Simulations and experiments have demonstrated the excellent performance of our all-fiber waveplates.