Ultraviolet Glue Research Articles

A Fabry–Perot Sensor with Cascaded Polymer Films Based on Vernier Effect for Simultaneous Measurement of Relative Humidity and Temperature

In this paper, fiber sensor based on Vernier effect for simultaneous measurement of relative humidity (RH) and temperature is proposed. The sensor is fabricated by coating two kinds of ultraviolet (UV) glue with different refractive indexes (RI) and thicknesses on the end face of a fiber patch cord. The thicknesses of two films are controlled to generate the Vernier effect. The inner film is formed by a cured lower-RI UV glue. The exterior film is formed by a cured higher-RI UV glue, of which thickness is much thinner than the inner film. Through the analysis of the Fast Fourier Transform (FFT) of the reflective spectrum, the Vernier effect is formed by the inner lower-RI polymer cavity and the cavity composed of both polymer films. By calibrating the RH and temperature response of two peaks on the envelope of the reflection spectrum, simultaneous measurements of RH and temperature are realized by solving a set of quadratic equations. Experimental results show that the highest RH and temperature sensitivities of the sensor are 387.3 pm/%RH (in 20%RH to 90%RH) and -533.0 pm/°C (in 15 °C to 40 °C), respectively. The sensor has merits of low cost, simple fabrication, and high sensitivity, which makes it very attractive for applications that need to simultaneously monitor these two parameters.

Switchable multi-wavelength fiber laser based on a taper-coupled microbottle resonator

A multi-wavelength erbium-doped fiber laser (EDFL) based on a taper-coupled microbottle resonator is proposed and investigated experimentally. The taper-coupled microbottle resonator has the comb filter characteristics with Q factor 2.9 × 104, which is integrated into an EDFL system. The taper-coupled microbottle resonator was packaged by ultraviolet glue, which has excellent stability of output power and wavelength at room temperature. Then, switchable dual-, triple-, quad- and quint-wavelength fiber laser states can be achieved by adjusting the polarization controller (PC). Furthermore, for dual-wavelength and triple-wavelength laser state, the position of output wavelengths also can be precisely modulated with the PC. The developed multi-wavelength EDFL has the optical signal to noise ratio as high as 40 dBm, and the wavelength shift and peak power fluctuation are less than 0.03 nm and 6 dBm.

Highly Sensitive Ultrasonic Sensor Based on Polymer Bragg Grating and its Application for 3D Imaging of Seismic Physical Model

A miniaturepolymer Bragg grating (PBG) sensor is fabricated and employed for ultrasonic imaging of seismic physical models (SPMs). The sensing Bragg grating is inscribed into an ultraviolet (UV) glue polymer waveguide with a femtosecond laser. The uniform polymer waveguide is fabricated by sealing the UV glue into a capillary fibre through capillary effect. By using line-by-line inscription technique, the laser beam is scanned transversely to periodically modulate the refractive index of the polymer waveguide, leading to the formation of the PBGs with various grating lengths. The sensor response to ultrasonic waves are investigated experimentally. When compared to single-mode fiber Bragg grating and phase-shifted fiber Bragg grating, the PBG with the same reflectivity presents a higher response amplitude due to its lower Young’s modulus. Besides, the sensor has a good spectral stability when transferred from air to water due to the waterproof coating on the sensor end. Finally, the sensor is used to scan a large-scale 3D SPM and the structural features, such as fault, fluctuation, and depositional termination, can be distinctly reconstructed. The proposed PBG sensor provides a new technique with easy fabrication, high sensitivity, and good stability for high-fidelity ultrasonic imaging of seismicphysical models.

Long-period fiber grating humidity sensor based on spider silks

We propose a long-period fiber grating (LPFG) humidity sensor based on two kinds of spider silks. Both spider dragline silk (SpDS) and spider egg-case silk (SpECS) for sensor preparation are produced by the Araneus ventricosus. SpDS can contract up to half the original length in the axial direction when the ambient relative humidity (RH) increases due to its supercontraction property. However, the length of SpECS axial contraction is much smaller than that of SpDS as RH increases, because SpECS does not have the supercontraction property like SpDS. We fabricated a LPFG by irradiating a single-mode fiber with a high-frequency CO2 laser. One end of LPFG is fixed by ultraviolet glue, and the other end is inserted into the quartz round tube without fixing. Therefore, the unfixed end of LPFG serves as the movable end to ensure that the direction of movement of LPFG is controllable. In addition, SpDS and SpECS exert pull forces on LPFG in two opposite directions, and the overall structure forms an X shape. When the ambient RH increases, the length of SpDS becomes shorter due to the supercontraction property. It changes the structure curvature of LPFG, leading to the transmission spectrum shift. When the RH decreases, SpECS provides a recovery pull, like a spring, that restores SpDS to a taut state when it relaxes. The curvature of LPFG is reduced, and the transmission spectrum shifts in the opposite direction. Therefore, we monitor the RH by observing the wavelength shift of the transmission spectrum. Our sensor achieves humidity detection with − 0.2039 nm/%RH sensitivity in the 50%RH-80%RH range. Additionally, we can adjust the amount and length of the two spider silks to increase the maximum detection humidity range closer to 100% RH at the expense of reduced sensitivity. The proposed humidity sensor has the advantages of reversibility, good repeatability, and environmental friendliness.

Large-range and high-sensitivity fiber optic temperature sensor based on Fabry–Pérot interferometer combined with FBG

A compact fiber optic temperature sensor based on the Fabry–Pérot interferometer (FPI) combined with FBG is analyzed and demonstrated experimentally in this paper. The FPI is fabricated by splicing a single mode fiber (SMF) with a section of silicon tube filled with ultraviolet (UV) glue to form an air microcavity. Owing to the high thermo-expansion coefficient of UV glue, the sensor can achieve a high sensitivity. Besides, the cascaded FBG can be used to locate different temperature intervals, and therefore the detectable temperature range is largely extended. Experimental results indicate that the sensor has a temperature sensitivity of −4.665 nm/°C in a wide temperature range of −30 to 15 °C. In addition, our fiber temperature sensor also exhibited excellent consistency, good repeatability, and stability during the thermal cycle tests. Therefore, it has a good practical prospect.

High-sensitive fiber-optic pressure sensor based on Fabry-Perot interferometer filled with ultraviolet glue film and Vernier effect

A high sensitivity fiber-optic pressure sensor based on Fabry-Perot interferometer filled with ultraviolet (UV) glue film and Vernier effect was proposed and demonstrated. The sensor is composed of a sensing Fabry-Perot (FP) cavity and a reference FP cavity in parallel. The sensing cavity is fabricated by splicing a section of silica tube (ST) to the lead-in single-mode fiber (SMF), and filling a thin layer of UV glue at the end-face of the ST. The reference cavity is made by sandwiching a section of ST between two SMF. The parallel cavities generate the Vernier effect due to a similar free spectrum range, which significantly improves the sensitivity of the sensor. The proposed sensor with good repeatability and reliability was used to monitor the change of air pressure, and provided a high sensitivity of −38.3 nm/MPa. The sensor exhibited the potential applications in the fields of aerospace industry, biological diagnostics and environmental monitoring.

Flexible and tandem quantum-dot light-emitting diodes with individually addressable red/green/blue emission

Tandem quantum-dot light-emitting diodes (QLEDs) with multiple QLED elements vertically connected by the intermediate electrodes offer the advantages of high brightness and long lifetime. However, it is challenging to individually address each QLED element in conventional tandem structures. To address this challenge, here, transparent QLEDs built on flexible plastic substrates are developed as the building blocks for the tandem QLEDs. By vertically integrating a red, a green, and a blue transparent QLEDs with an ultraviolet glue, the resultant tandem QLED can emit separately controllable red/green/blue (R/G/B) emission with an external quantum efficiency (EQE) of 12.0%/8.5%/4.5%, respectively. Enabled by the transparent and extractable IZO electrodes, the QLED elements can also be connected in series or in parallel with an EQE of 24.8% or 8.2%, respectively. Our work provides a new implementation strategy for the realization of tandem QLEDs with individually addressable R/G/B emission for both display and lighting applications.

Optimization of quantum-dot light source and detection of the simulants of chemical warfare agent

Near-infrared (NIR) PbS quantum-dot (QD) light sources were prepared by combining a chip-on-board (COB) LED chip with a PbS QD solution and ultraviolet (UV) glue. A method through adjusting the ratio of QD solution to UV glue to optimize the performance of the light source and match chemicals absorption spectra was presented in this paper. The relationship and trade-offs between different QD–glue ratios of the PbS QD light sources and the performance parameters including light intensity and PL peak were investigated at external voltages from 12.4 V to 13.4 V. The experimental results suggest that the PbS QD light intensity was the highest when the QD–glue ratio was 1:9. The light source was stable when the QD–glue ratio no more than 1:9. The PL peak of the QD light source were redshifted as the QD-glue ratio increased. In addition, two QDs materials with PL peak of 1172 ± 20 nm and 1380 ± 50 nm were selected to prepare the light source. The PL peak of the QD light source can match the absorption peak of the simulants of chemical warfare agents including Dimethyl Methylphosphonate (DMMP) and Dichloromethane (CH2Cl2) accurate by changing the QD-glue ratio. The results suggest that the QD light source optimized were match the sample well, which achieved qualitative detection. And the standard curves were establish, realized the quantitative detection of the sample concentration from 2% to 100%. Therefore, adjusting the QD–glue ratio is a feasible and effective method to improve the luminous intensity, the stability, and the Selectivity of sample detection of the QD light source. And the QDs with tunable emissions have great potential for multiple chemicals detect

High-sensitivity temperature sensor based on ultraviolet glue-filled silica capillary tube

A novel high-sensitivity temperature sensor based on Ultraviolet (UV) glue-filled silica capillary tube (SCT) structure is proposed and demonstrated experimentally. The proposed sensor can be easily fabricated by inserting a section of single-mode fibre (SMF) with a flat end-face into the silica capillary tube, then filling the UV glue into the silica capillary tube and forming a Fabry–Perot interferometer (FPI). In addition, the sensor structure is much more stable because the SCT can protect the formed FPI. The temperature response of the sensor is demonstrated, and it’s important that the temperature sensitivity of the proposed sensor reaches 0.963 nm/°C with a perfect linearity of 99.8%. The proposed sensor with high-sensitivity, ease of fabrication and reliability has great application potential in temperature sensing.

Stress-insensitive vector curvature sensor based on a single fiber Bragg grating

Abstract A stress-insensitive vector curvature sensor based on a single fiber Bragg grating (FBG) is proposed and experimentally demonstrated. The sensor is easily fabricated by encapsulating an FBG on a thin steel plate with ultraviolet glue. When the FBG deviates from the neutral plane, its effective refractive index and grating constant are changed by bending, therefore, the sensor can realize the curvature measurement. The sensitivity of the sensor in convex bending is 553.65 pm/m−1 in the range of 0.4798–1.3569 m−1. The sensor can realize vector measurement of curvature due to the opposite stress direction on the two sides of the neutral plane during bending. The concave curvature sensitivity of the sensor is −811.19 pm/m−1 in the range of 0.4798–1.3569 m−1. Due to the large stiffness of the thin steel plate, the package of the FBG makes it insensitive to small axial stress. The favorable stability of the sensor facilitates its practical application in the measurement of curvature and inclination. This sensor has the advantage of simple manufacture, low cost, and easy industrial production.

Fabrication of dual-parameter fiber-optic sensor by cascading FBG with FPI for simultaneous measurement of temperature and gas pressure

A dual-parameter fiber-optic sensor based on fiber Bragg grating (FBG) cascaded with Fabry–Pérot interferometer (FPI) structure is described and demonstrated to measure temperature and gas pressure simultaneously. The proposed sensing structure consists of an extrinsic FPI in the form of hemispherical ultraviolet (UV) curing glue capped on a FBG end face. The spectral interference peak produced by the UV glue FPI is sensitive to ambient temperature and gas pressure variations, whereas the reflection spectrum of FBG only depends on temperature and insensitive to pressure change, therefore, the temperature and gas pressure can be simultaneously measured by this cascaded sensor. Experimental results show that the sensor has higher temperature and gas pressure sensitivities of 223.4 pm/° C and 24.99 nm/MPa in a range from 30 ∘C to 110 ∘C and from 0.1 MPa to 0.7 MPa. Utilizing the temperature-dependent sensitivity of FBG, a constructed sensitivity matrix is used to distinguish measurement of temperature and gas pressure, and the measurement resolutions are determined to be 0.086 ∘C and 0.730 KPa. This sensing architecture is not only an effective method for single-point multi-parameter measurement, but also has merits of high sensitivity, compactness, ease of fabrication and low cost, which make it valuable for biosensors and medical applications.

Cylinder-type fiber-optic Vernier probe based on cascaded Fabry-Perot interferometers with a controlled FSR ratio.

We designed a cylinder-type fiber-optic Vernier probe based on cascaded Fabry-Perot interferometers (FPIs) in this paper. It is fabricated by inserting a short single-mode fiber (SMF) column into a large-aperture hollow-core fiber (LA-HCF) with an internal diameter of 150µm, which structures a length adjusted air microcavity with the lead-in SMF inserted into the LA-HCF from the other end. The length of the SMF column is 537.9µm. By adjusting the distance between the SMF column and the lead-in SMF, the spectral change is displayed intuitively, and the Vernier spectra are recorded and analyzed. In sensitivity analysis, the probe is encapsulated in the medical needle by ultraviolet glue as a small body thermometer when the length of the air microcavity is 715.5µm. The experiment shows that the sensitivity of the Vernier envelope is 12.55 times higher than that of the high-frequency comb. This design can effectively reduce the preparation difficulty of the optical fiber Vernier sensor based on cascaded FPIs, and can expand the applied fields by using different fibers and materials.

紫外胶基底中CdSe/ZnS量子点的吸收与色散非线性关系的确定

紫外胶基底中CdSe/ZnS量子点的吸收与色散非线性关系的确定

Programmable LDEP technology to fabricate versatile master molds for PDMS continuous-flow microfluidic applications

This paper presents an innovative versatile method aiming at rapid fabrication of a master for polydimethylsiloxane (PDMS) molding. This technology is relying on liquid dielectrophoresis electromechanical microfluidic transduction for programmable ultraviolet (UV) glue manipulation. It enables formation of the master in a tailor-made approach, avoiding the need of micromachined structures unlike in conventional methods. The principle is simple: UV glue, while in liquid phase, is actuated onto an array of electrodes patterned on a Si substrate and cured afterward by UV exposure. The silicon chip and the glue microstructures defined atop of it then play the role of a master for PDMS molding. The glue microstructures’ shape is hemispherical which is of high interest for many microfluidic applications. This concept is assessed and validated with two different PDMS chip replica designs, both of them illustrating representative applications in continuous microfluidic: a T-junction design for inflow droplet generation and a “Quake” type valve. Lastly, this protocol has shown to be recyclable since the UV glue microstructures once formed can be easily removed by immersion in an acetone bath, such as the chip is reset and can be reprogrammed afterward to build another glue channels geometry.

Eliminating the External Libration Sound for the Optical Microsphere-Taper Coupling Structure

This paper describes the effects of the microsphere-taper coupling structure from the external libration Sound, especially the impact on the coupling distance. Here two solutions have been proposed. One approach is to cover the system with a insulation shield. The other is to integrate the coupling structure with the ultraviolet glue. The results show that both measures are viable. The packaged microsphere-taper coupling structure is entirety separated from the nonego, making the structure not be disturbed by the external libration sound. In the subsequent experimentation, the packaged structure will have a good prospect.

Fill Tube Assembly Development for Omega and NIF Shell Applications

A new technique has been developed for attaching glass and polyimide tubes to National Ignition Facility and OMEGA-scale capsules. Resorcinol-formaldehyde foam and CD fill tube assemblies are designed for OMEGA laser capabilities by the University of Rochester Laboratory for Laser Energetics. Because of the porous structure of the foam, test procedures have been implemented to guarantee the target assemblies are leaktight under room and cryogenic temperatures. Based on the type and conditions of the target, ultraviolet glue or two-part epoxy glue is applied to particular sections on the assembly. Development has been conducted to overcome issues dealing with the adhesives, test procedures, and fill tube designs described in this paper.