Splicing Machine Research Articles

Optical Fiber Alignment Aid with Image Processing on FPGA-based System

This paper introduces an innovative and efficient solution for achieving precise optical fiber alignment in fiber optic splicing applications. By harnessing the capabilities of FPGA-based real-time image processing, the system surpasses the required frame rate of 20 frames per second, ensuring swift and accurate alignment. With a verified resolution of approximately 1 pixel per µm, the system offers high precision suitable for various applications. Through advanced image processing techniques, the system calculates precise correction values for each frame, resulting in fast and accurate alignment of fiber cores and cladding. This unique feature enhances performance and adaptability, leading to substantial reduction in splice wastage. By integrating motorized alignment stages and guided machine vision, the system provides a robust and automated approach to fiber optic alignment. The FPGA-driven stepper motors enable precise and controlled fiber movements with micrometer-level step resolutions. The calculated correction factors effectively guide the alignment process, with deviations from actual results impressively low – a maximum of 12 µm in the Y correction factor and 7 µm in the X correction factor. This reliability makes the system a crucial component in any optical fiber splicing machine. Furthermore, the paper emphasizes the ability to handle specialty fiber alignment contributes significantly to cost-effective manufacturing of fiber optic components and modules. By ensuring precise and optimal fiber alignment, the system mitigates signal loss, leading to improved performance and reduced production costs.

High-Temperature Measurement of a Fiber Probe Sensor Based on the Michelson Interferometer.

In this paper, a fiber probe high-temperature sensor based on the Michelson Interferometer (MI) is proposed and experimentally verified. We used a fiber splicing machine to fabricate a taper of the single-mode fiber (SMF) end. The high order modes were excited at the taper, so that different modes were transmitted forward in the fiber and reflected by the end face of the fiber and then recoupled back to the fiber core to form MI. For comparison, we also coated a thin gold film on the fiber end to improve the reflectivity, and the reflection intensity was improved by 16 dB. The experimental results showed that the temperature sensitivity at 1506 nm was 80 pm/°C (100 °C~450 °C) and 109 pm/°C (450 °C~900 °C). The repeated heating and cooling processes showed that the MI structure had good stability at a temperature up to 900 °C. This fiber probe sensor has the advantages of a small size, simple structure, easy manufacturing, good stability, and broad application prospects in industrial and other environments.

Mechanical characterisation of pneumatically-spliced carbon fibre yarns as reinforcements for polymer composites

An investigation into the mechanical response of pneumatically-spliced carbon fibre yarns as a potential reinforcing material for polymer composites is presented. High strength mechanical connections between carbon fibre yarns are produced by joining short discontinuous tows into longer lengths via fibre entanglement. The effect of altering the number of high-pressure air pulses fired by a commercially available (Airbond 701H) splicing machine, to form the tow-tow connection, on load bearing capacity and linear stiffness is first evaluated on splices between virgin T700SC-24K-50C carbon fibre tows. The best performing spliced configuration is subsequently utilised in reinforcing unidirectional epoxy laminates, which are mechanically characterised, and their properties compared to those of various continuous fibre and chopped strand mat panels. Results presented in this study demonstrate that pneumatic splicing provides a high strength and sustainable solution for reinforcing polymers with discontinuous (approx. >50 mm in length) virgin, off-cut or waste carbon fibre yarns. It is speculated that with further research, quasi-continuous yarns remanufactured by splicing waste fibres could provide a novel material for weaving, braiding, non-crimp fabrics, or use in 3D printing applications.

Connecting Technologies for Coaxial Dual Core Optical Fiber

Coaxial dual core optical fiber (CDCF) with a lensed tip can be used for microparticle trapping, shooting, and spectra analyzing. In this paper, we introduce the connection technology of CDCFs. On the one hand, the CDCFs can be fusion spliced easily and quickly by using the single-mode fiber (SMF) splicing machine, because they have a completely axisymmetric structure. On the other hand, a fan-in device based on the principle of “vanishing core” is designed, and the insertion loss due to fabrication process error is analyzed. Fan-in devices are fabricated and tested. The average insertion loss of the annular core and central core is 1.48 dB and 0.76 dB, respectively.

Composed multicore fiber structure for direction-sensitive curvature monitoring

The present work deals with a curvature sensor that consists of two segments of asymmetric multicore fiber (MCF) fusion spliced with standard single mode fiber (SMF). The MCF comprises three strongly coupled cores; one of such cores is at the geometrical center of the MCF. The two segments of MCF are short, have different lengths (less than 2 cm each), and are rotated 180° with respect to each other. The fabrication of the sensor was carried out with a fusion splicing machine that has the means for rotating optical fibers. It is demonstrated that the sensor behaves as two SMF–MCF–SMF structures in series, and consequently, it has enhanced sensitivity. The device proposed here can be used to sense the direction and amplitude of curvature by monitoring either wavelength shifts or intensity changes. In the latter case, high curvature sensitivity was observed. The device can also be used for the development of other highly sensitive sensors to monitor, for example, vibrations, force, pressure, or any other parameter that induces periodic or local curvature or bending to the MCF segments.

A Refractive Index Sensor Based on a Fabry–Perot Interferometer Manufactured by NIR Laser Microdrilling and Electric Arc Fusion

In-line Fabry–Perot cavities manufactured by a new technique using electric arc fusion of NIR laser microdrilled optical fiber flat tips were studied herein for refractive index sensing. Sensors were produced by creating an initial hole on the tip of a standard single-mode telecommunication optical fiber using a Q-switched Nd:YAG laser. Laser ablation and plasma formation processes created 5 to 10 micron cavities. Then, a standard splicing machine was used to fuse the microdrilled fiber with another one, thus creating cavities with lengths around 100 micrometers. This length has been proven to be necessary to obtain an interferometric signal with good fringe visibility when illuminating it in the C-band. Then, the sensing tip of the fiber, with the resulting air cavity, was submitted to several cleaves to enhance the signal and, therefore, its response as a sensor, with final lengths between tens of centimeters for the longest and hundreds of microns for the shortest. The experimental results were analyzed via two signal analysis techniques, fringe visibility and fast Fourier transform, for comparison purposes. In absolute values, the obtained sensitivities varied between 0.31 nm−1/RIU and about 8 nm−1/RIU using the latter method and between about 34 dB/RIU and 54 dB/RIU when analyzing the fringe visibility.

Protruding-shaped SiO2-microtip: from fabrication innovation to microphotonic device construction

In this Letter, we first proposed a new technology to prepare protruding-shaped SiO2-microtips (PSSMs): transient spinning technology (TST). By designing the operation steps and controlling the discharge parameters of a fiber splicing machine (Furukawa S178a), the protruding-shaped SiO2-microtips with different structural parameters can be fabricated simply, quickly, and efficiently. Two kinds of microtip photonic devices were designed: (1)a high-sensitivity gas refractive index Mach-Zehnder interferometer sensor based on the coned microtip and (2)an efficient LP11-mode selective exciter based on the lensed microtip. Furthermore, the PSSMs have more potential applications, such as optical fiber tweezers, optical fiber Raman probes, and scanning near-field optical microscopy.

Improvement of a Splicing Machine to Decrease Abrupt Tension Changes and Tail Defects during the Roll Exchange Process in a Roll-to-Roll Manufacturing System

The use of the splicing system is necessary to exchange a fully unwound roll to a new one without stopping the roll-to-roll manufacturing machine. However, abrupt tension changes and tail defects, which is an overlap of completely unwound films with films in the process of being unwound, could occur during the roll exchange phase causing film loss and deterioration of product quality. Herein, we improved the splicing machine in an industrial scale R2R manufacturing system to decrease abrupt tension errors and tail defects. First, the effects of the factors generating the tail defects in the splicing machine on the net tail lengths were analyzed using designed mathematical models. Furthermore, the reason for the abrupt tension disturbance in the roll exchange process was determined. Based on the analyses, a passive dancer system was applied to the unwinding section to attenuate the tension error, and the time interval between the pressing and cutting phases was decreased by changing the signal processing method of the previous version of the splicing machine. Experimental results showed that the abrupt tension change was decreased by an average of 46.5%, while tail lengths were decreased by more than 2.5 times, thereby verifying the superior performance of the upgraded splicing machine.

Aparallel digraphs and splicing machines

The concepts of a splicing machine and of an aparalled digraph are introduced. A splicing machine is basically a means to uniquely obtain all circular sequences on a finite alphabet by splicing together circular sequences from a small finite set of “generators”. The existence and uniqueness of the central object related to an aparallel digraph, the strong component, is proved, and this strong component is shown to be the unique fixed point of a natural operator defined on sets of vertices of the digraph. A digraph is shown to be a splicing machine if and only if it is the strong component of an aparallel digraph. Motivation comes, on the applied side, from the splicing of circular sequences on a finite alphabet and, on the theoretical side, from the Banach fixed point theorem.

Temperature insensitive curvature sensor based on cascading photonic crystal fiber

Abstract A temperature insensitive curvature sensor is proposed based on cascading photonic crystal fiber. Using the arc fusion splicing method, this sensor is fabricated by cascading together a single-mode fiber (SMF), a three layers air holes structure of photonic crystal fiber (3PCF), a five layers air holes structure of photonic crystal fiber (5PCF) and a SMF in turn. So the structure SMF-3PCF-5PCF-SMF can be obtained with a total length of 20 mm. During the process of fabrication, the splicing machine parameters and the length of each optical fiber are adjusted to obtain a high sensitivity curvature sensor. The experimental results show that the curvature sensitivity is −8.40 nm/m−1 in the curvature variation range of 0–1.09 m−1, which also show good linearity. In the range of 30–90 °C, the temperature sensitivity is only about 3.24 pm/°C, indicating that the sensor is not sensitive to temperature. The sensor not only has the advantages of easy fabricating, simple structure, high sensitivity but also can solve the problem of temperature measurement cross sensitivity, so it can be used for different areas including aerospace, large-scale bridge, architectural structure health monitoring and so on.

Temperature Compensated Strain Sensor Based on Long-Period Gratings and Microspheres

In this letter, we present a new structure composed by a long-period grating (LPG) and a microsphere in series, which works as a modal interferometer besides allowing the mode coupled to the cladding to be coupled back to the core. The LPG was written by the electric arc technique and the microsphere was fabricated using a splicing machine. It is possible to use this new structure for simultaneous measurement of strain and temperature. It also allows one to obtain a temperature compensated strain sensor by using a proper data processing algorithm, which utilizes two distinct wavelengths for strain and temperature. Then, a strain sensitivity of 0.86 pm/με and a reduced temperature sensitivity of 0.7 pm/°C were achieved.

Evaluation of Energy Balance on Human Telomerase Reverse Transcriptase (hTERT) Alternative Splicing by Semi-quantitative RT-PCR in Human Umbilical Vein Endothelial Cells.

Background:Decreased high-energy phosphate level is involved in endothelial cell injury and dysfunction. Reduced telomerase activity in endothelial cells in parallel with reduced energy levels might be due to altered direction of alternative splicing machine as a complication of depleted energy during the process of atherosclerosis.Materials and Methods:Isolated human umbilical vein endothelial cells (HUVECs) were treated for 24 hours by oligomycine (OM) and 2-deoxy glucose (2-DG). After 24 hours, the effect of energy depletion on telomerase splicing pattern was evaluated using RT-PCR. Indeed, in both treated and untargeted cells, nitric oxide (NO) and von Willebrand factor (vWF) were measured.Results:ATP was depleted in treated cells by 43.9% compared with control group. We observed a slight decrease in NO levels (P = 0.09) and vWF (P = 0.395) in the setting of 49.36% ATP depletion. In both groups, no telomerase gene expression was seen. Telomerase and housekeeping gene expression were found in positive control group (colon cancer tissue) and sample tissue.Conclusions:The absence of telomerase gene expression in HUVECs might be due to the mortality of these cells or the low level of telomerase gene expression in these cells under normal circumstances.

The nuts and bolts of the endogenous spliceosome.

The complex life of pre-mRNA from transcription to the production of mRNA that can be exported from the nucleus to the cytoplasm to encode for proteins entails intricate coordination and regulation of a network of processing events. Coordination is required between transcription and splicing and between several processing events including 5' and 3' end processing, splicing, alternative splicing and editing that are major contributors to the diversity of the human proteome, and occur within a huge and dynamic macromolecular machine-the endogenous spliceosome. Detailed mechanistic insight of the splicing reaction was gained from studies of the in vitro spliceosome assembled on a single intron. Because most pre-mRNAs are multiintronic that undergo alternative splicing, the in vivo splicing machine requires additional elements to those of the in vitro machine, to account for all these diverse functions. Information about the endogenous spliceosome is emerging from imaging studies in intact and live cells that support the cotranscriptional commitment to splicing model and provide information about splicing kinetics in vivo. Another source comes from studies of the in vivo assembled spliceosome, isolated from cell nuclei under native conditions-the supraspliceosome-that individually package pre-mRNA transcripts of different sizes and number of introns into complexes of a unique structure, indicating their universal nature. Recent years have portrayed new players affecting alternative splicing and novel connections between splicing, transcription and chromatin. The challenge ahead is to elucidate the structure and function of the endogenous spliceosome and decipher the regulation and coordination of its network of processing activities. WIREs RNA 2017, 8:e1377. doi: 10.1002/wrna.1377 For further resources related to this article, please visit the WIREs website.

Structure-function analysis and genetic interactions of the SmG, SmE, and SmF subunits of the yeast Sm protein ring.

A seven-subunit Sm protein ring forms a core scaffold of the U1, U2, U4, and U5 snRNPs that direct pre-mRNA splicing. Using human snRNP structures to guide mutagenesis in Saccharomyces cerevisiae, we gained new insights into structure–function relationships of the SmG, SmE, and SmF subunits. An alanine scan of 19 conserved amino acids of these three proteins, comprising the Sm RNA binding sites or inter-subunit interfaces, revealed that, with the exception of Arg74 in SmF, none are essential for yeast growth. Yet, for SmG, SmE, and SmF, as for many components of the yeast spliceosome, the effects of perturbing protein–RNA and protein–protein interactions are masked by built-in functional redundancies of the splicing machine. For example, tests for genetic interactions with non-Sm splicing factors showed that many benign mutations of SmG, SmE, and SmF (and of SmB and SmD3) were synthetically lethal with null alleles of U2 snRNP subunits Lea1 and Msl1. Tests of pairwise combinations of SmG, SmE, SmF, SmB, and SmD3 alleles highlighted the inherent redundancies within the Sm ring, whereby simultaneous mutations of the RNA binding sites of any two of the Sm subunits are lethal. Our results suggest that six intact RNA binding sites in the Sm ring suffice for function but five sites may not.

Alternate Method for Determination of Glue-line Tensile Strength of Spliced Veneers in Czech Republic

Quality control is a crucial part of any manufacturing unit, as it assures compliance to established standards as well as maintenance of product quality for internal management purposes. Quality control of spliced veneer in Czech wood based industries is mainly based on ČSN 49 2315 and ČSN 49 2320 standards, which rely on measurement of crack length in finished product. This method has been satisfactorily used since 1985 but requirements of wood based industry has changed a lot in these years. We propose an alternate method for mesurement of tensile strength of spliced veneers. Samples of specified size spliced were taken as mentioned in details and they were subjected to tensile stength measurement. An addtional adhesive tape was used to avoid intra-material fibres disjointing, so that inter-material tensile strength can be measured for spliced veneers. This test can be used for on – site optimization of splicing machine units as well as regular quality control of spliced venners.

Magnetic field sensor based on asymmetric optical fiber taper and magnetic fluid

We report an optical fiber magnetic field sensor by merging the advantages of magnetic fluid and a core–cladding–mode interferometer which is directly fabricated on a standard single-mode fiber by using an arc fusion splicing machine. The sensing performances of the sensors are controllable by designing the parameters of the asymmetric-tapered structure. Experimental results show that the sensor with axial offset of 168μm and taper waist diameter of 45μm not only has good optical properties but also a relatively high magnetic-field sensitivity of ∼162.06pm/mT ranging from 0 to 21.4mT. The proposed sensors would find potential applications in weak magnetic sensing fields.

Metal ghosts in the splicing machine

Chemical analysis of the spliceosome's active site reveals that it is the RNA components of this enzyme complex that coordinate the catalytic metal ions responsible for production of a spliced messenger RNA. See Article p.229 The RNA- and protein-containing spliceosome complex excises introns from pre-mRNAs. On the basis of the existence of self-splicing group II introns, a type of ribozyme, it was hypothesized more than thirty years ago that the small nuclear RNAs (snRNAs) of the spliceosome would catalyse splicing. However, despite decades of research, no definitive evidence for a role of either RNA or protein in splicing catalysis has been reported. Now Joseph Piccirilli, Jonathan Staley and colleagues identify the metal-containing U6 snRNA as the catalyst. Moreover, the data strongly suggest a common evolutionary origin for the spliceosome and group II introns.

S-tapered photonic crystal fiber interferometers for refractive index sensing

An experimental investigation on an S-tapered photonic crystal fiber interferometer is presented. The whole fabrication process was carried out using a standard splicing machine. The interferometer shows a compact and stable structure with a waist diameter of 110 μm, taper length of 280 μm, and axial offset of 40 μm. The transmission spectra indicated that it is highly sensitive to the surrounding refractive index (RI) and insensitive to temperature. Resolutions of 3.3×10 −4 and 8.0×10 −5 RI units were achieved in the 1.33 to 1.38 and 1.38 to 1.44 range, respectively. Furthermore, its temperature dependence was only 4 pm/°C .

Refractive Index Sensor Based on S-Tapered Photonic Crystal Fiber

The S-tapered PCF interferometer for refractive index sensing was demonstrated in this letter. The whole fabrication process was carried out using a standard splicing machine. It has a compact and stable structure since the S-shape assumes the same function with elongating taper. The sensor exhibits highly SRI sensitivity, which is found to be 8.0 10-5 RIU in 1.38-1.44 and the temperature dependence is only 4.2 pm/°C low 100°C.

Micro-Ball Lensed Fiber-Based Glucose Sensor

The compact micro-ball lens structure fabricated at the cleaved tip of a microfiber coupler (MFC) is proposed and demonstrated for sensing various glucose concentrations in deionized water. The MFC was made by fusing and tapering two optical fibers using a flame brushing technique. It was then cleaved at the center of the minimum waist region to form a ball lens at the tip by an arcing technique using a fusion splicing machine. The proposed glucose sensor uses the micro-ball lensed fiber as a probe and a mirror as a target. The working mechanism of this device is based on the observed reduction in the peak power of the sensor wavelength spectrum as the concentration of glucose is increased. For a concentration change from 0 to 12 volume%, the ouput intensity of the sensor decreases linearly from -57.4 to -60.5ndBm with a sensitivity of 0.26 dB/% and a linearity of more than 99%.