Twin Core Research Articles

Photonics for AI and AI for photonics integration : Materials and characteristics

Photonics and artificial intelligence (AI) are two rapidly advancing fields that have the potential to revolutionize various technological domains. This paper explores the convergence of photonics and AI, focusing on the integration of photonics for AI applications and the utilization of AI techniques for advancing photonics technology. Paper explores the materials used in photonics for AI systems, highlighting their unique characteristics and advantages. Additionally, examine how AI methodologies such as machine learning and neural networks are applied in optimizing photonics systems, enhancing their sensitivity performance and enabling novel functionalities. Through this exploration, results obtained provide sensitivity analysis and refractive index calculation of twin core photonic crystal fiber (PCF). The synergistic relationship between photonics and AI and its potential implications for advancing information and optimization sciences is also presented.

3D printing specialty multi-function twin core Bi/Er co-doped silica optical fibres for ultra-broadband polarized near infrared emission and sensing applications

3D printing specialty multi-function twin core Bi/Er co-doped silica optical fibres for ultra-broadband polarized near infrared emission and sensing applications

Passive Flow Control for Centrifugal Compressors with Bents Intake Manifold

Centrifugal compressors installations often require bents conduits at the intake due to space constraints. The intake bent manifold creates flow distortion affecting unfavorably the global performance of the compressor. The degradation caused by the inadequate inlet conditions due to turbulence and inlet flow disturbance, which negatively affects the flowing fluid through the curved intake manifold. Hence, significant distortions, within presence of single or twin core vortices whirling off center of the impeller intake alter flow incidence angle and consequently the impeller circumferential energy. Furthermore, inadequate bends configurations generate higher incidence angles, which lead to boundary layer separation and stalling. This paper deals with a 3D numerical investigations of dual bends located upstream of the centrifugal compressor. Several bend setting positions at the compressor intake describing various sequences of intake piping are considered. As first results, specific positions of dual bends are identified for fewer flow disturbance at the impeller eye and stable outflow controlling the incidence angel in a passive mode. it is less cumbersome and cost effective compared to additional devices. For practical industrial prediction, this investigation contribute also toward a mathematical correlation to check the adequacy of intermediate manifold configuration in order to predict the corresponding incidence angle at the impeller intake of the centrifugal compressor for enhanced performance and instantaneous control.

Highly sensitive twin core photonic crystal fiber for hazardous cancer cell detection in THz frequency regime

Highly sensitive twin core photonic crystal fiber for hazardous cancer cell detection in THz frequency regime

An asymmetric slotted structured twin core photonic crystal fiber based highly sensitive surface plasmon resonance refractive index biosensor

A butterfly-shaped core photonic crystal fibers with less asymmetric rectangular and circular air holes are proposed, and their properties are numerically analyzed. The sensor construction is reduced to only seven air holes and uses surface plasmons stimulated inside gold (Au) strips for simplicity in manufacture and high sensitivity. Gold is employed as an effective plasmonic metal throughout this design to create resonant effects and is located away from the proposed structure to make production easier. Maximum amplitude sensitivity for the proposed sensor is 228.89 RIU−1, maximum wavelength sensitivity is 88,000 nm/RIU, and maximum wavelength resolution is 1.14 × 10−6RIU−1 for y-polarized mode where the figure of merit is 65.78 RIU−1 with a linearity of 0.9905. The proposed sensor can detect the RI of unspecified analytes between 1.27 and 1.40, allowing for the analysis of many different types of analytes, such as viruses, cancer cells, sugars, proteins, DNA/RNA and many more.

Twin core photonic crystal fiber based temperature sensor with improved sensitivity over a wide range of temperature

Twin core photonic crystal fiber based temperature sensor with improved sensitivity over a wide range of temperature

High SMSR and widely tunable multi-wavelength erbium doped fiber laser based on cascaded filters

In this paper, a widely tunable multi-wavelength erbium doped fiber laser (EDFL) with high side mode suppression ratio (SMSR) is proposed and experimentally demonstrated. With the cascaded structure of Sagnac loop filter (SLF) and a homemade twin core photonic crystal fiber (TCPCF), the proposed EDFL could achieve a wide tunable range without sacrificing the SMSR. By properly adjusting the polarization controller (PC) and the bending stage, switchable single-, dual-, and triple-wavelength lasing outputs can be obtained. The tuning range can reach up to 23 nm and the highest SMSR is 57 dB for single-wavelength lasing. Moreover, dual-wavelength lasing outputs with the tuning range of 19 nm and SMSR higher than 40 dB can also be obtained. The proposed widely tunable EDFL with high SMSR has great significance for many applications such as optical fiber communication, distributed fiber optic sensing and microwave generation.

Performance improvement of a plasmonic tapered twin–core fiber optical tweezers

In this paper, a plasmonic tapered twin-core fiber optical tweezers is proposed. Numerical simulations are carried out to fully investigate its performance. Strong resonance behavior is observed at λ = 14.7 µm. It is shown that in the proposed structure, high values of trapping force can be achieved due to intrinsic field enhancement of plasmonic effect. Moreover, it is observed that our proposed structure can trap and induce force to the particles as small as 0.01 µm radius size.

Intensity-modulated bend sensor by using a twin core fiber: theoretical and experimental studies.

A new optical fiber bend sensor is proposed and demonstrated based on a sandwich structure created by splicing a segment of twin core fiber (TCF) between two segments of single mode fibers (SMFs). One core of the TCF is aligned with the cores of two segments of SMFs. An incident beam is directed into the TCF by the lead-in SMF. Light couples back and forth between two cores. The bend sensing performance of the sensor is investigated by intensity-modulated method. The intensity of the operation wavelength is modulated by the change of refractive index and geometrical deformation in the bent TCF. Experimental results show such a bend sensor achieves sensitivity of +0.671 /m-1 and resolution of 0.003 m-1 in the range of 0 to 1.25 m-1. In addition, the sensitivity and bend measurement range can be flexibly adjusted through selection of the length of TCF and sensing configuration. As such, the proposed sensor can be further developed for large or small bend ranges measurement.

Twin core photonic crystal fiber refractive index sensor for early detection of blood cancer

This paper presents a twin-core photonic crystal fiber (TC-PCF) for early detection of blood cancer based on refractive index (RI) of the normal and cancerous blood cell. The samples of the normal and cancerous cells are considered at 30–70% and 80% in liquid form, respectively, and proposed to be infiltrated into the center air hole which is comparatively larger than the others. By considering the refractive index (RI), the change in the coupling length and transmitted spectrum of the proposed TC-PCF for the normal and cancerous cells is observed by using the finite element method (FEM). According to the transmitted spectrum shift, the proposed sensor can exhibit a large sensitivity of 8571.43 nm/RIU. Owing to simple detection mechanism, the proposed TC-PCF sensor can be used for blood cancer detection effectively and cheaply.

Twin core photonic crystal fiber for temperature sensing

Photonic crystal material based twin core photonic crystal fiber (TC-PCF) is proposed for sensing of temperature. Two independent waveguides present in TC-PCF due to two solid cores in the cross-section separated by an air hole. When the optical light is injected into one core at the input side of twin core, then due to mode coupling between two waveguides light is transmitted from one core to another core along the fiber. Transmission spectrum of TC-PCF is observed which is sensitive to the temperature because the refractive index of background material of TC-PCF depends on temperature. The temperature sensitivity of 6 cm long TC-PCF is 18.5 pm/0C, which can sense the temperature up to 600 °C.

Evaluation of disturbance induced on soft offshore sediments by two types of gravity piston coring techniques

Sample disturbance is still a key issue in offshore investigations, especially when logistic and financial limitations do not allow the use of drilling equipment. This paper focuses on the comparison between the disturbance induced by a conventional free-fall piston corer (FF) and a modified piston corer (AD) equipped with a velocity control (Angel Descent method). Twin core samples were retrieved in two successions of pelitic sediments with a prevailing non-clayey fraction and a non-negligible sandy fraction. Comparison was based on different acquisition, physical and mechanical parameters ranging from accelerometer data to magnetic susceptibility logs and geotechnical parameters from laboratory investigations, including oedometer compression tests and cyclic simple shear tests. Accelerometer data highlighted the sharp reduction in velocity obtained for AD samples. Magnetic susceptibility logs, characterized by a pattern of peaks induced by several volcaniclastic levels present in the succession, indicated that the AD method significantly reduces core shortening. Among geotechnical investigations, cyclic shear tests provided small-strain shear moduli always higher in AD samples, whilst the response of oedometer compression tests was equivocal. In fact, methods for assessing sample disturbance have demonstrated to bear limited effectiveness when applied to soils with relatively low clay content and significant overconsolidation as it is the case of the studied sediments.

Solitons in nonlinear directional couplers with optical metamaterials by exp(− Φ(ξ))-expansion

This paper studies solitons in optical couplers that are made up from metamaterials. Twin core as well as multiple-core couplers are considered. The study is conducted by the aid of exp(− Φ(ξ))-expansion scheme for four forms of nonlinearity and they are Kerr law, power law, parabolic law and dual-power law. Singular and combo-soliton solutions are recovered from this algorithm.

Study of Transient Enclosure Voltage Coupling to Secondary Cables in a Gas-Insulated Substation

Transient enclosure voltage (TEV) induces a relative potential difference between grounding conductors and then couples to secondary cables and may cause malfunction and even damage to secondary equipment. This study investigates the coupling mechanism of TEV to secondary cables from an experimental point of view and presents a cable model suitable for calculation. Experiments are carried out on test platforms established in a laboratory. The experimental results indicate that the magnitudes of port voltages are roughly 1.5‰ of TEV magnitudes, and the waveform of the start port voltage has the same profile but in antiphase with that of the end port voltage. Moreover, only common-mode voltage with no differential-mode voltage exists for the twin core cable. Based on these results, an equivalent circuit for a secondary cable is proposed. This circuit can generate similar waveforms as those measured in the experiment. The experimental and theoretical results presented in this paper should prove helpful for evaluating the interference severity of secondary cables resulting from TEV for the electromagnetic protection of secondary ports.

Etching twin core fiber for the temperature-independent refractive index sensing

We proposed an ultra-compact chemically etched twin core fiber (TCF) based optic refractive index (RI) sensor, in which the etched fiber was fabricated by immersing in an aqueous solution of hydrofluoric acid (HF) to etch the cladding. Due to the multipath evolutions of light during the TCF, the mode induced interference pattern can be used for measurement. Numerical simulations were performed, demonstrating that only the cladding mode strongly interacts with the surrounding media, and the higher cladding modes will be more sensitive to external medium. In the experiment demonstration, the RI response characteristics of the sensor were investigated, which shows a relatively high RI sensitivity and a much low temperature cross-sensitivity with about 1.06 × 10−6 RIU °C−1. Due to low cost and easy fabrication, the sensor can be a suitable candidate in the biochemical field.

Imbibition Oil Recovery From Tight Rocks With Dual-Wettability Networks in the Montney

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 185076, “Imbibition Oil Recovery From Tight Rocks With Dual-Wettability Pore Networks: A Montney Case Study,” by Ali Javaheri and Hassan Dehghanpour, SPE, University of Alberta, and James Wood, SPE, Encana, prepared for the 2017 SPE Canada Unconventional Resources Conference, Calgary, 15–16 February. The paper has not been peer reviewed. Previous studies demonstrate that Montney rock samples present a dual-wettability pore network. Recovery of the oil retained in the small hydrophobic pores is uniquely challenging. In this study, the authors applied dual-core-imbibition (DCI) methods on several Montney core plugs and introduced the imbibition-recovery (IR) trio to investigate the recovery mechanisms in rocks with dual-wettability pore networks. Introduction Spontaneous imbibition of aqueous phases (water, brine, or surfactant solutions) in fractured sandstone has been studied as a possible mechanism for enhanced oil recovery. Extensive experimental and mathematical investigations have been conducted for relating the imbibition rate and total oil recovery to the capillary and gravity forces and geometrical parameters. However, rock/fluid interactions in tight and shale reservoirs are more complicated than those seen in conventional reservoirs. In addition to capillary forces, organic materials and reactive clay minerals can influence the fluid flow and storage in the small pores of low-permeability rocks. The affinity of reservoir rock to a particular fluid in such formations depends especially on rock mineralogy and properties of the organic matter that coats and fills the pores. Previous comparative imbibition tests show that the affinity of the Montney samples to oil is significantly higher than their affinity to water. This behavior was explained by the presence of water-repellent pores within or coated by solid bitumen or pyrobitumen. In the complete paper, the authors focus on imbibition oil recovery of samples cored from the Montney Formation and investigate the role of rock-fabric complexities, such as dual-wettability characteristics, in oil recovery by water imbibition. A detailed discussion of materials used in the spontaneous-imbibition and oil-recovery tests, including rock and fluid properties, is included in the complete paper. Methodology The authors conducted three sets of comparative tests on five twin core plugs, which were dry cut from Montney cores. The samples are characterized by measuring mineral concentration, total-organic-carbon (TOC) content, porosity, and permeability. The methodology is fully described in the complete paper.

Metrics of Urban Sustainability: A Case Study of Changing Downtowns in Thunder Bay, Canada

Thunder Bay, a medium-sized city in Northern Ontario, has a twin downtown core model, arising from the merging of two former cities in 1970. Its north core, designated as the City’s Entertainment District has received considerable investment, notably a major waterfront renewal project undertaken in 2009 as part of an overall strategy towards downtown revitalization. Greater diversity of commercial functions and increasing residential capacity in downtowns are considered positive steps towards sustainable urban development. It is hoped the leadership taken by the City in its downtown capital investments can stimulate others (corporations and individuals) to re-invest in both living and working in more central locations to the benefit of environmental sustainability indicators like journey-to-work (distance and mode selected) and residential density. This article tracks changes in business composition and residential capacity during a five year period via the development of an intensive database of business and institutional activities. Urban sustainability metrics developed include residential capacity and density, business vacancy rates and business composition and turnover, which complement an existing measure of land-use diversity developed in earlier research. While major capital investments in downtown revitalization (such as the waterfront project) have fairly long-term impact horizons, data suggest some positive trends in the developed metrics in the downtown north core since 2009. In particular, there have been notable investments in waterfront condos and downtown lofts and some diversification in the food retailing and restaurant sectors. However, overall trends in downtown commerce are currently flat, indicative of a struggling local economy and a continued suburbanization of key commercial sectors.

Tight rock wettability and its relationship to other petrophysical properties: A Montney case study

Understanding and modelling the wettability of tight rocks is essential for designing fracturing and treatment fluids. In this paper, we measure and analyze spontaneous imbibition of water and oil into five twin core plugs drilled from the cores of a well drilled in the Montney Formation, an unconventional oil and gas play in the Western Canadian Sedimentary Basin. We characterize the samples by measuring the mineralogy using XRD (x-ray diffraction), total organic carbon content, porosity, and permeability. Interestingly, the equilibrated water uptake of the five samples is similar, while, their oil uptake increases by increasing the core porosity and permeability. We define two wetta-bility indices for the oil phase based on the slope and equilibrium values of water and oil imbibition curves. Both indices increase by increasing porosity and permeability, with the slope affinity index showing a stronger correlation. This observation suggests that part of the pore network has a stronger affinity to oil than to water. We also observe that the two indices decrease by increasing neutron porosity and gamma ray parameters measured by wireline logging tools. The samples with higher gamma ray and neutron porosity are expected to have greater clay content, and thus less effective porosity and permeability.

Highly sensitive curvature sensor based on asymmetrical twin core fiber and multimode fiber

A highly sensitive curvature sensor based on asymmetrical twin core fiber (TCF) and multimode fiber (MMF) is proposed and experimentally demonstrated. By applying the coupled-mode theory and equivalent refractive index model, we theoretically analyze the uncoupled feature of the TCF and the relationship between peak wavelength and the curvature. Two segments of MMF used as beam splitter and combiner are embedded on the two ends of the TCF, and the extinction ratio of the comb transmission spectrum is about 15dB. The experimental result shows that the curvature sensitivity of the sensor can be achieved as high as 103.35nm/m−1 ranging from 0.24m−1 to 0.6m−1, and the strain sensitivity is up to −4.01pm/με in the range from 0μεto 1400με. The simultaneous detection of the curvature and strain can be realized. The temperature sensitivity is 0.431nm/°C in the range from 40°C to 70°C. This fiber sensor exhibits the advantages of low cost, easy and repeated fabrication, and high sensitivity.

失配型双芯长周期光纤光栅弯曲矢量传感

失配型双芯长周期光纤光栅弯曲矢量传感