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Showing papers on "Optical fiber published in 2020"


Reference BookDOI
10 Sep 2020
TL;DR: In this article, the authors discuss optical science, engineering, and technology topics covered include the laser and its many commercial and industrial applications, the new optical materials, gradient index optics, electro-and acousto-optics, fiber optics and communications, optical computing and pattern recognition, optical data reading, recording and storage, biomedical instrumentation, industrial robotics, integrated optics, infrared and ultraviolet systems
Abstract: This book discusses optical science, engineering, and technology Topics covered include the laser and its many commercial and industrial applications, the new optical materials, gradient index optics, electro- and acousto-optics, fiber optics and communications, optical computing and pattern recognition, optical data reading, recording and storage, biomedical instrumentation, industrial robotics, integrated optics, infrared and ultraviolet systems

643 citations


Journal ArticleDOI
TL;DR: This is the first comprehensive review on methods and materials for use in optical sensing of pH values and on applications of such sensors.
Abstract: This is the first comprehensive review on methods and materials for use in optical sensing of pH values and on applications of such sensors. The Review starts with an introduction that contains subsections on the definition of the pH value, a brief look back on optical methods for sensing of pH, on the effects of ionic strength on pH values and pKa values, on the selectivity, sensitivity, precision, dynamic ranges, and temperature dependence of such sensors. Commonly used optical sensing schemes are covered in a next main chapter, with subsections on methods based on absorptiometry, reflectometry, luminescence, refractive index, surface plasmon resonance, photonic crystals, turbidity, mechanical displacement, interferometry, and solvatochromism. This is followed by sections on absorptiometric and luminescent molecular probes for use pH in sensors. Further large sections cover polymeric hosts and supports, and methods for immobilization of indicator dyes. Further and more specific sections summarize the state of the art in materials with dual functionality (indicator and host), nanomaterials, sensors based on upconversion and 2-photon absorption, multiparameter sensors, imaging, and sensors for extreme pH values. A chapter on the many sensing formats has subsections on planar, fiber optic, evanescent wave, refractive index, surface plasmon resonance and holography based sensor designs, and on distributed sensing. Another section summarizes selected applications in areas, such as medicine, biology, oceanography, bioprocess monitoring, corrosion studies, on the use of pH sensors as transducers in biosensors and chemical sensors, and their integration into flow-injection analyzers, microfluidic devices, and lab-on-a-chip systems. An extra section is devoted to current challenges, with subsections on challenges of general nature and those of specific nature. A concluding section gives an outlook on potential future trends and perspectives.

233 citations


Journal ArticleDOI
TL;DR: By using a powerful class of micro-comb called soliton crystals, this work achieves ultra-high data transmission over 75 km of standard optical fibre using a single integrated chip source and demonstrates the capability of optical micro-combs to perform in demanding and practical optical communications networks.
Abstract: Micro-combs - optical frequency combs generated by integrated micro-cavity resonators – offer the full potential of their bulk counterparts, but in an integrated footprint. They have enabled breakthroughs in many fields including spectroscopy, microwave photonics, frequency synthesis, optical ranging, quantum sources, metrology and ultrahigh capacity data transmission. Here, by using a powerful class of micro-comb called soliton crystals, we achieve ultra-high data transmission over 75 km of standard optical fibre using a single integrated chip source. We demonstrate a line rate of 44.2 Terabits s−1 using the telecommunications C-band at 1550 nm with a spectral efficiency of 10.4 bits s−1 Hz−1. Soliton crystals exhibit robust and stable generation and operation as well as a high intrinsic efficiency that, together with an extremely low soliton micro-comb spacing of 48.9 GHz enable the use of a very high coherent data modulation format (64 QAM - quadrature amplitude modulated). This work demonstrates the capability of optical micro-combs to perform in demanding and practical optical communications networks. Microcombs provide many opportunities for integration in optical communications systems. Here, the authors implement a soliton crystal microcomb as a tool to demonstrate more than 44 Tb/s communications with high spectral efficiency.

227 citations


Journal ArticleDOI
TL;DR: Strain sensors made from the organohydrogel fibers accurately capture high‐frequency and high‐speed motion and exhibit little drift for 1000 stretch–release cycles, and are powerful for detecting rapid cyclic motions such as engine valves and are difficult to reach by previously reported conductive fibers.
Abstract: Stretchable conductive fibers are key elements for next-generation flexible electronics. Most existing conductive fibers are electron-based, opaque, relatively rigid, and show a significant increase in resistance during stretching. Accordingly, soft, stretchable, and transparent ion-conductive hydrogel fibers have attracted significant attention. However, hydrogel fibers are difficult to manufacture and easy to dry and freeze, which significantly hinders their wide range of applications. Herein, organohydrogel fibers are designed to address these challenges. First, a newly designed hybrid crosslinking strategy continuously wet-spins hydrogel fibers, which are transformed into organohydrogel fibers by simple solvent replacement. The organohydrogel fibers show excellent antifreezing ( 5 months), transparency, and stretchability. The predominantly covalently crosslinked network ensures the fibers have a high dynamic mechanical stability with negligible hysteresis and creep, from which previous conductive fibers usually suffer. Accordingly, strain sensors made from the organohydrogel fibers accurately capture high-frequency (4 Hz) and high-speed (24 cm s-1 ) motion and exhibit little drift for 1000 stretch-release cycles, and are powerful for detecting rapid cyclic motions such as engine valves and are difficult to reach by previously reported conductive fibers. The organohydrogel fibers also demonstrate potential as wearable anisotropic sensors, data gloves, soft electrodes, and optical fibers.

176 citations


Journal ArticleDOI
TL;DR: Fiber optic sensing technology has become mature because of acceptable costs, compact instrumentation, high accuracy and the capability of performing measurements at inaccessible sites, over large distances, in strong (electro) magnetic fields and in harsh environment.
Abstract: High-quality optical fibers can be produced now at a low cost and large quantity, and this has further promoted the development of fiber optic (chemical) sensors. After over 30 years of innovation, fiber optic sensing technology has become mature because of acceptable costs, compact instrumentation, high accuracy and the capability of performing measurements at inaccessible sites, over large distances, in strong (electro)magnetic fields and in harsh environment. The technology is still proceeding quickly in terms of innovation, and respective applications have been found in highly diversified fields. This review covers work published in the time period between October 2015 and October 2019. It is written in continuation of previous reviews.

169 citations


Journal ArticleDOI
TL;DR: Fiber Bragg grating has embraced the area of fiber optics since the early days of its discovery, and most fiber optic sensor systems today make use of fiber Bragg-grating technology as discussed by the authors.
Abstract: Fiber Bragg grating has embraced the area of fiber optics since the early days of its discovery, and most fiber optic sensor systems today make use of fiber Bragg grating technology Researchers have gained enormous attention in the field of fiber Bragg grating (FBG)-based sensing due to its inherent advantages, such as small size, fast response, distributed sensing, and immunity to the electromagnetic field Fiber Bragg grating technology is popularly used in measurements of various physical parameters, such as pressure, temperature, and strain for civil engineering, industrial engineering, military, maritime, and aerospace applications Nowadays, strong emphasis is given to structure health monitoring of various engineering and civil structures, which can be easily achieved with FBG-based sensors Depending on the type of grating, FBG can be uniform, long, chirped, tilted or phase shifted having periodic perturbation of refractive index inside core of the optical fiber Basic fundamentals of FBG and recent progress of fiber Bragg grating-based sensors used in various applications for temperature, pressure, liquid level, strain, and refractive index sensing have been reviewed A major problem of temperature cross sensitivity that occurs in FBG-based sensing requires temperature compensation technique that has also been discussed in this paper

163 citations


Journal ArticleDOI
TL;DR: The developed sensors are based on the optical power variation, which results in a fully portable and low-cost technique and indicate the possibility of detecting basic activities such as walking, sitting on a chair and squatting.
Abstract: This paper presents the development and application of a multiparameter, quasi-distributed smart textile based on embedded highly stretchable polymer optical fiber (POF) sensors. The POF is fabricated using the light polymerization spinning process, resulting a highly stretchable optical fiber, so-called LPS-POF, with Young’s modulus and elastic limits of 15 MPa and 17%, respectively. The differential scanning calorimetry shows a thermal stability of the LPS-POF in temperature range of 13–40 °C. The developed sensors are based on the optical power variation, which results in a fully portable and low-cost technique. In order to obtain a multiplexed sensor system, a technique based on flexible light emitting diodes (LEDs) on–off keying modulation is applied, where each LED represents the response of one sensor. The smart textile comprises of LPS-POF and three flexible LEDs embedded in neoprene textile fabric. The performance of the system is evaluated for temperature, transverse force and angular displacement detection at different planes. The sensors presented high linearity (mean determination coefficient of 0.99) and high repeatability (inter-measurement deviations below 5%). The sensor is also applied in activity detection, where the principal component analysis (PCA) was applied in the sensors responses and, in conjunction with clustering techniques such as k-means, indicate the possibility of detecting basic activities such as walking, sitting on a chair and squatting.

116 citations


Journal ArticleDOI
TL;DR: In this article, the variable-coefficients complex cubic-quintic Ginzburg-Landau equation (CCQGLE) influenced by higher-order effects and nonlinear gain is considered.
Abstract: In this work, the variable-coefficients complex cubic–quintic Ginzburg–Landau equation (CCQGLE) influenced by higher-order effects and nonlinear gain is considered. Based on the asymmetric method, analytic one-soliton solution for the variable-coefficients CCQGLE is constructed for the first time. In addition, with some certain conditions, the periodic wave and dromion-like structures are derived. The results obtained may be helpful in understanding the solitons amplification and solitons management in optical fiber.

116 citations


Journal ArticleDOI
01 Apr 2020-Optik
TL;DR: In this article, a proposed compensation simulation model to handle not only chromatic dispersion but also polarization mode dispersion (PMD) simultaneously is presented. And the model is designed to analyze and simulate dispersion compensation technique which is based on deploying both fiber Bragg grating and emulator together till 250 km long of optical fiber.

99 citations


Journal ArticleDOI
02 Jun 2020-Analyst
TL;DR: A roadmap to deploy plasmonic sensors is provided by reviewing the current successes and by laying out the directions the field is currently taking to increase the use of field-deployed plasMonic sensors at the point-of-care, in the environment and in industries.
Abstract: Plasmonic sensors are ideally suited for the design of small, integrated, and portable devices that can be employed in situ for the detection of analytes relevant to environmental sciences, clinical diagnostics, infectious diseases, food, and industrial applications. To successfully deploy plasmonic sensors, scaled-down analytical devices based on surface plasmon resonance (SPR) and localized surface plasmon resonance (LSPR) must integrate optics, plasmonic materials, surface chemistry, fluidics, detectors and data processing in a functional instrument with a small footprint. The field has significantly progressed from the implementation of the various components in specifically designed prism-based instruments to the use of nanomaterials, optical fibers and smartphones to yield increasingly portable devices, which have been shown for a number of applications in the laboratory and deployed on site for environmental, biomedical/clinical, and food applications. A roadmap to deploy plasmonic sensors is provided by reviewing the current successes and by laying out the directions the field is currently taking to increase the use of field-deployed plasmonic sensors at the point-of-care, in the environment and in industries.

97 citations



Journal ArticleDOI
09 Apr 2020-Sensors
TL;DR: Achievements in the area of temperature optical fiber sensors, different configurations of the sensors reported over the last five years, and application of this technology in biomedical applications are reviewed.
Abstract: The use of sensors in the real world is on the rise, providing information on medical diagnostics for healthcare and improving quality of life. Optical fiber sensors, as a result of their unique properties (small dimensions, capability of multiplexing, chemical inertness, and immunity to electromagnetic fields) have found wide applications, ranging from structural health monitoring to biomedical and point-of-care instrumentation. Furthermore, these sensors usually have good linearity, rapid response for real-time monitoring, and high sensitivity to external perturbations. Optical fiber sensors, thus, present several features that make them extremely attractive for a wide variety of applications, especially biomedical applications. This paper reviews achievements in the area of temperature optical fiber sensors, different configurations of the sensors reported over the last five years, and application of this technology in biomedical applications.

Journal ArticleDOI
TL;DR: The system of partial differential equations for moving optical solitons in fiber Bragg gratings is studied in this article, where traveling wave reductions are used to look for solutions of the system of equations.

Proceedings ArticleDOI
08 Mar 2020
TL;DR: An effectively single-moded, 1.7km long hollow core Nested Antiresonant Nodeless Fiber (NANF) is reported with record-low 0.28dB/km loss from 1510 to 1600nm, which further reduces the loss gap with standard all-glass single mode fibers.
Abstract: We report an effectively single-moded, 1.7km long hollow core Nested Antiresonant Nodeless Fiber (NANF) with record-low 0.28dB/km loss from 1510 to 1600nm, which further reduces the loss gap with standard all-glass single mode fibers.

Journal ArticleDOI
TL;DR: An optical fiber temperature and strain fiber sensor based on the fewmode fiber (FMF) and the fiber Bragg grating (FBG) is proposed and demonstrated in this article, which is fabricated by a length of FMF offset splicing with one section of single-mode fiber.

Journal ArticleDOI
TL;DR: Hollow core fibres of nested antiresonant design are reported, with losses comparable or lower than achievable in solid glass fibres around technologically relevant wavelengths of 660, 850, and 1060 nm, which offers the potential for advances in quantum communications, data transmission, and laser power delivery.
Abstract: For over 50 years, pure or doped silica glass optical fibres have been an unrivalled platform for the transmission of laser light and optical data at wavelengths from the visible to the near infra-red. Rayleigh scattering, arising from frozen-in density fluctuations in the glass, fundamentally limits the minimum attenuation of these fibres and hence restricts their application, especially at shorter wavelengths. Guiding light in hollow (air) core fibres offers a potential way to overcome this insurmountable attenuation limit set by the glass’s scattering, but requires reduction of all the other loss-inducing mechanisms. Here we report hollow core fibres, of nested antiresonant design, with losses comparable or lower than achievable in solid glass fibres around technologically relevant wavelengths of 660, 850, and 1060 nm. Their lower than Rayleigh scattering loss in an air-guiding structure offers the potential for advances in quantum communications, data transmission, and laser power delivery. Hollow core fibers have low light attenuation because the light travels through air rather than glass, but other sources of loss have limited the performance so far. Here the authors design and demonstrate a Nested Antiresonant Nodeless hollow core fiber that has losses competitive with standard solid-core fiber at several important wavelengths.

Journal ArticleDOI
TL;DR: This manuscript examines various optical fiber types including tube fibers, solid core fiber, hollow-core photonic bandgap, anti-resonant fibers, porous-core fibers, metamaterial-based fibers, and their guiding mechanisms for terahertz waveguides.
Abstract: Lying between optical and microwave ranges, the terahertz band in the electromagnetic spectrum is attracting increased attention. Optical fibers are essential for developing the full potential of complex terahertz systems. In this manuscript, we review the optimal materials, the guiding mechanisms, the fabrication methodologies, the characterization methods and the applications of such terahertz waveguides. We examine various optical fiber types including tube fibers, solid core fiber, hollow-core photonic bandgap, anti-resonant fibers, porous-core fibers, metamaterial-based fibers, and their guiding mechanisms. The optimal materials for terahertz applications are discussed. The past and present trends of fabrication methods, including drilling, stacking, extrusion and 3D printing, are elaborated. Fiber characterization methods including different optics for terahertz time-domain spectroscopy (THz-TDS) setups are reviewed and application areas including short-distance data transmission, imaging, sensing, and spectroscopy are discussed.

Journal ArticleDOI
TL;DR: In this paper, a dual-mode anti-resonant hollow-core optical fiber was used to detect all-fiber gas (acetylene) down to ppt (parts-per-trillion) and 1% instability over a period of 3 hours.
Abstract: Laser spectroscopy outperforms electrochemical and semiconductor gas sensors in selectivity and environmental survivability. However, the performance of the state-of-the-art laser sensors is still insufficient for many high precision applications. Here, we report mode-phase-difference photothermal spectroscopy with a dual-mode anti-resonant hollow-core optical fiber and demonstrate all-fiber gas (acetylene) detection down to ppt (parts-per-trillion) and <1% instability over a period of 3 hours. An anti-resonant hollow-core fiber could be designed to transmit light signals over a broad wavelength range from visible to infrared, covering molecular absorption lines of many important gases. This would enable multi-component gas detection with a single sensing element and pave the way for ultra-precision gas sensing for medical, environmental and industrial applications. Typically, the performance of the state-of-the-art laser sensors is insufficient for many high precision applications. Here, the authors report mode-phase-difference photothermal spectroscopy with a dual-mode anti-resonant hollow-core optical fiber and demonstrate acetylene detection with ultra-high sensitivity.

Journal ArticleDOI
TL;DR: In this review, the present sensors are compared and analyzed from the aspects of the geometry, material and dimensions of plasmonic nano-arrays and the main research directions and progress are summarized.
Abstract: For sensors based on the electromagnetic resonance whether the surface plasmon resonance (SPR) or localized surface plasmon resonance (LSPR), enhancing the light-matter interactions is the most critical and important way to improve their performance. Plasmonic nano-arrays are a kind of periodic metal or dielectric nanostructure formed by nanofabrication technology and can effectively enhance the light-matter interactions by tuning structural parameters to cause different optical effects due to their ultra-high degree of freedom. At the same time, a plug-and-play, remote microsensor suitable for limited environments (such as in vivo systems) may be realized due to the rise of lab-on-fiber technology and the progress of nanofabrication technology for unconventional substrates (such as an optical fiber tip). In this paper, the advantages and disadvantages of different nanofabrication technologies are briefly introduced and compared firstly, and then the applications of optical fiber sensors (OFS) based on different plasmonic nano-arrays are reviewed. Plasmonic nano-array OFS are divided into two categories: refractive index sensors based on the sensitivity of the array to the surrounding environment and surface enhanced Raman scattering (SERS) sensors based on the enhancement ability of the local electric field around the array. In this review, the present sensors are compared and analyzed from the aspects of the geometry, material and dimensions of plasmonic nano-arrays and the main research directions and progress are summarized. Finally, the future development trend is proposed.

Journal ArticleDOI
TL;DR: Initial tests show that the fabrication strategy of MoS2 is amenable to other transition metal dichalcogenides, making these embedded fibres versatile for several all-fibre nonlinear optics and optoelectronics applications.
Abstract: Nonlinear optical fibres have been employed for a vast number of applications, including optical frequency conversion, ultrafast laser and optical communication1–4. In current manufacturing technologies, nonlinearity is realized by the injection of nonlinear materials into fibres5–7 or the fabrication of microstructured fibres8–10. Both strategies, however, suffer from either low optical nonlinearity or poor design flexibility. Here, we report the direct growth of MoS2, a highly nonlinear two-dimensional material11, onto the internal walls of a SiO2 optical fibre. This growth is realized via a two-step chemical vapour deposition method, where a solid precursor is pre-deposited to guarantee a homogeneous feedstock before achieving uniform two-dimensional material growth along the entire fibre walls. By using the as-fabricated 25-cm-long fibre, both second- and third-harmonic generation could be enhanced by ~300 times compared with monolayer MoS2/silica. Propagation losses remain at ~0.1 dB cm–1 for a wide frequency range. In addition, we demonstrate an all-fibre mode-locked laser (~6 mW output, ~500 fs pulse width and ~41 MHz repetition rate) by integrating the two-dimensional-material-embedded optical fibre as a saturable absorber. Initial tests show that our fabrication strategy is amenable to other transition metal dichalcogenides, making these embedded fibres versatile for several all-fibre nonlinear optics and optoelectronics applications. The internal surface of an optical fibre can be covered by uniform two-dimensional-material layers for highly nonlinear and low-loss light propagation.

Journal ArticleDOI
TL;DR: A biocompatible and robust fiber surface plasmon resonance (SPR) temperature sensor was fabricated based on an alcohol-filled hollow-core fiber that has the potential to realizing multiparameter or distributed temperature measurement.
Abstract: A biocompatible and robust fiber surface plasmon resonance (SPR) temperature sensor was fabricated based on an alcohol-filled hollow-core fiber. The fabrication process of this designed sensor included Ag film coating, liquid injection, and fusion splicing, which was low cost and efficient. Due to the high refractive index sensitivity of the SPR effect and the high thermal optical coefficient of alcohol, the designed sensor performed well in temperature sensing, whose linear sensitivity reached as high as 1.16 nm/°C in the range of 35.5 °C–70.1 °C. Being small in size, low in fabrication cost, and highly sensitive in performance, this sensor is suitable for temperature detection during biological and chemical reactions and has the potential to realizing multiparameter or distributed temperature measurement.

Journal ArticleDOI
TL;DR: In this paper, the authors have simulated the spatial optical transceiver system based on measured index multimode optical plastic fibers channel with 1.5 km distance and achieved better performance in maximum Q-factor and receiver sensitivity response better than other plastic optical fibers channels.
Abstract: This study has simulated the spatial optical transceiver system based on measured index multimode optical plastic fibers channel with 1 Tb/s in 1.5 km distance. These plastic optical fibers are simply step index polycarbonate, step index polystyrene, step index polymethylmethacrylate, graded index polymethylmethacrylate and graded index cyclic transparent optical fiber (GI-CYTOP). Maximum Q-factor, optical signal power at optical fiber channel, receiver sensitivity, and coupling coefficient for sample of modes are measured based on GI-CYTOP fiber for the comparison between the previous model and the proposed model. This study clarified the enhancement of both maximum Q-factor and receiver sensitivity even though at high signal losses. The optimized Q-factor and receiver sensitivity are obtained for various plastic optical fiber channels. Power intensity level of dominant mode–based GI-CYTOP fiber channel is measured. The proposed model has presented better performance based on GI-CYTOP fiber channel in maximum Q-factor, which is within the percentage ratio ranging from 45.65 to 53.26%, optical signal power is within the percentage ratio ranging from 32.87 to 44.77%, and receiver sensitivity is within the percentage ratio ranging from 6.3 to 12.26% than the previous model at transmission distance ranges from 500 to 1500 m and bit rate of 2.5 Gb/s. GI-CYTOP fiber clarified better performance in maximum Q-factor and receiver sensitivity response better than other plastic optical fibers channels.

Journal ArticleDOI
06 Nov 2020
TL;DR: A broad overview of current fabrication technologies, classified as top-down, bottom-up, and material transfer, for patterning optical fiber tips is presented in this paper, where typical structures integrated on fiber tips and their known and potential applications, categorized with respect to functional structure configurations, including optical functionalization and electrical integration.
Abstract: The flat endface of an optical fiber tip is an emerging light-coupled microscopic platform that combines fiber optics with planar micro- and nanotechnologies. Since different materials and structures are integrated onto the endfaces, optical fiber tip devices have miniature sizes, diverse integrated functions, and low insertion losses, making them suitable for all-optical networks. In recent decades, the increasing demand for multifunctional optical fibers has created opportunities to develop various structures on fiber tips. Meanwhile, the unconventional shape of optical fibers presents challenges involving the adaptation of standard planar micro- and nanostructure preparation strategies for fiber tips. In this context, researchers are committed to exploring and optimizing fiber tip manufacturing techniques, thereby paving the way for future integrated all-fiber devices with multifunctional applications. First, we present a broad overview of current fabrication technologies, classified as “top-down,” “bottom-up,” and “material transfer” methods, for patterning optical fiber tips. Next, we review typical structures integrated on fiber tips and their known and potential applications, categorized with respect to functional structure configurations, including “optical functionalization” and “electrical integration.” Finally, we discuss the prospects for future opportunities involving multifunctional integrated fiber tips.

Journal ArticleDOI
TL;DR: In this article, the Fabry Perot laser properties with high pump lasers for upgrading fiber optic transceiver systems are outlined. But the physical structures of the light source are not taken into account such as active layer length and active layer width.
Abstract: The work has outlined the Fabry Perot laser properties with high pump lasers for upgrading fiber optic transceiver systems. The physical structures of the light source are taken into account such as active layer length and active layer width. High pump laser is used for providing strength to the signal through the transmission/reception stages. Peak and minimum signal power levels are measured in the spectral frequency domain and time domain. Signal amplitude level margin is also measured with the optimum physical parameters of the light source. The optimum operation system performance efficiency is achieved with an active layer length of 0.06 cm, and active layer width suitable is 1.5 × 10−4 cm.

Journal ArticleDOI
TL;DR: In this article, the authors demonstrate a line rate of 44.2 Terabits per second using the telecommunications C band at 1550nm with a spectral efficiency, a critically important performance metric, of 10.4 bits/s/Hz.
Abstract: Micro-combs [1 - 4], optical frequency combs generated by integrated micro-cavity resonators, offer the full potential of their bulk counterparts [5,6], but in an integrated footprint. The discovery of temporal soliton states (DKS dissipative Kerr solitons) [4,7-11] as a means of modelocking microcombs has enabled breakthroughs in many fields including spectroscopy [12,13], microwave photonics [14], frequency synthesis [15], optical ranging [16,17], quantum sources [18,19], metrology [20,21] and more. One of their most promising applications has been optical fibre communications where they have enabled massively parallel ultrahigh capacity multiplexed data transmission [22,23]. Here, by using a new and powerful class of microcomb called soliton crystals [11], we achieve unprecedented data transmission over standard optical fibre using a single integrated chip source. We demonstrate a line rate of 44.2 Terabits per second using the telecommunications C band at 1550nm with a spectral efficiency, a critically important performance metric, of 10.4 bits/s/Hz. Soliton crystals exhibit robust and stable generation and operation as well as a high intrinsic efficiency that, together with a low soliton microcomb spacing of 48.9 GHz enable the use of a very high coherent data modulation format of 64 QAM (quadrature amplitude modulated). We demonstrate error free transmission over 75 km of standard optical fibre in the laboratory as well as in a field trial over an installed metropolitan optical fibre network. These experiments were greatly aided by the ability of the soliton crystals to operate without stabilization or feedback control. This work demonstrates the capability of optical soliton crystal microcombs to perform in demanding and practical optical communications networks.

Journal ArticleDOI
01 Jan 2020-Optik
TL;DR: In this article, the geometric evolution of a linearly polarized light wave coupling into an optical fiber and the rotation of the polarization plane in a 3D Riemannian manifold is discussed.

Journal ArticleDOI
TL;DR: In this article, the authors review the continuous efforts to understand, design, and fabricate this hollow-core anti-resonant fiber with the aim of lower loss and wider bandwidth.
Abstract: In the research field of hollow-core optical fiber (HCF), one type of fiber geometry with a leaky mode nature has unexpectedly taken center stage over the last couple of years: the so-called hollow-core anti-resonant fiber (ARF). The guidance mechanism of this ARF has been elucidated explicitly, the optical performance of the fiber has improved significantly, and the range of potential fiber application areas has expanded steadily. This paper will review our continuous efforts to understand, design, and fabricate this hollow-core ARF with the aim of lower loss and wider bandwidth. We also explore the possibility of using an advanced form of ARF in communications applications. In the long journey of looking for optical fibers that provide better performance than conventional solid-core glass fibers, exploitation of the hidden potential of artificial photonic micro-structures will continue to advance.

Journal ArticleDOI
TL;DR: In this paper, an optical cellulose fiber for water sensoring was prepared by using a sequential preparation strategy, in which the core of the fiber was prepared from dissolved cellulose, in [EMIM]OAc, which was dry-wet spun into water.
Abstract: In this study an optical cellulose fiber for water sensoring was prepared by using a sequential preparation strategy. The core of the fiber was prepared from dissolved cellulose, in [EMIM]OAc, which was dry–wet spun into water. The cladding layer on the cellulose core was produced by coating a layer of cellulose acetate, dissolved in acetone, using a filament coater. The chemical and optical properties of both regenerated cellulose and cellulose acetate were studied from cast films using ultraviolet–visible and Fourier-transform infrared spectroscopy measurements. Regenerated cellulose film was observed to absorb UV light, passing the visible light wavelengths. Cellulose acetate film was observed to pass the whole light wavelength range. The mechanical strength and topography of the prepared optical cellulose fiber were investigated through tensile testing and SEM imaging. The mechanical performance of the fiber was similar to previously reported values in the literature (tensile strength of 120 MPa). The prepared optical fiber guided light in the range of 500–1400 nm. The attenuation constant of the cellulose fiber was observed to be 6.3 dB/cm at 1300 nm. The use of prepared optical cellulose fiber in a water sensor application was demonstrated. When the fiber was placed in water, a clear attenuation in the light intensity was observed. The studied optical fiber could be used in sensor applications, in which easy modifiability and high thermal resistance are beneficial characteristics. Coaxial cellulose acetate-regenerated cellulose fiber for transporting light in sensor optical fiber sensor applications.

Journal ArticleDOI
TL;DR: The aim is to demonstrate the BiLSTM is comparable with the conventional model-driven SSF-based method for direct-detection optical fiber system and think the proposed method could be a supplementary technique that can be used for the existing simulation system and could also be a potential option for future simulation methods.
Abstract: A data-driven fiber channel modeling method based on deep learning (DL) is introduced in an optical communication system. In this study, bidirectional long short-term memory (BiLSTM) is selected from a diverse range of DL algorithms to perform fiber channel modeling for on–off keying and pulse amplitude modulation 4 signals. Compared with the conventional model-driven split-step Fourier (SSF)-based method, the proposed method yields similar results based on the comprehensive comparison of multiple characteristics associated with the generated optical signals, including the optical amplitude and phase waveforms in the time domain, optical spectrum components in the frequency domain, and eye diagrams after detection in the electrical domain. Additionally, the effects of multiple factors on the modeled fiber channel have also be investigated, including fiber length, fiber nonlinearity, dispersion, data pattern, pulse shaping, and sample rate. The satisfactory fitting results and acceptable mean square errors indicate that the approximate transfer function of the fiber channel is learned by the BiLSTM. Moreover, compared with repetitive iteration SSF, the computing time is significantly reduced by the BiLSTM owing to its independence on fiber length and insensitivity to data size and launch power. Our aim is to demonstrate the BiLSTM is comparable with the conventional model-driven SSF-based method for direct-detection optical fiber system. We think the proposed method could be a supplementary technique that can be used for the existing simulation system and could also be a potential option for future simulation methods.

Journal ArticleDOI
TL;DR: In this article, six different types of optical fibers (SMF, HNLF, DFF, NZDSF, LEAF, step core, and LEAF-ring core) can be used for different number of channels (16, 32, 64, and 80) at different bit rates.
Abstract: In this study, six different types of optical fibers (SMF, HNLF, HNL-DFF, NZDSF, LEAF (step core) and LEAF (ring core)) can be used for different number of channels (16, 32, 64, and 80) at different bit rates to calculate the quality factor for these types of optical fibers at the optimum length for max BER × 10−9 and min BER × 10−12. By using the software Optisystem version 13, the work has been demonstrated and compared with previous study to find the best one under the same operating conditions.