Objective: To establish a DNA detection platform based on a tapered optical fiber to detect Leptospira DNA by targeting the leptospiral secY gene.Methods: The biosensor works on the principle of light propagating in t...Objective: To establish a DNA detection platform based on a tapered optical fiber to detect Leptospira DNA by targeting the leptospiral secY gene.Methods: The biosensor works on the principle of light propagating in the special geometry of the optical fiber tapered from a waist diameter of 125 to 12 μm. The fiber surface was functionalized through a cascade of chemical treatments and the immobilization of a DNA capture probe targeting the secY gene. The presence of the target DNA was determined from the wavelength shift in the optical transmission spectrum.Results: The biosensor demonstrated good sensitivity, detecting Leptospira DNA at 0.001 ng/μL, and was selective for Leptospira DNA without cross-reactivity with non-leptospiral microorganisms. The biosensor specifically detected DNA that was specifically amplified through the loop-mediated isothermal amplification approach.Conclusions: These findings warrant the potential of this platform to be developed as a novel alternative approach to diagnose leptospirosis.展开更多
A temperature sensor is demonstrated and fabricated by coating the single-mode tapered optical fiber with temperature-sensitive silicone rubber. It works on the change of the evanescent fields in the tapered optical f...A temperature sensor is demonstrated and fabricated by coating the single-mode tapered optical fiber with temperature-sensitive silicone rubber. It works on the change of the evanescent fields in the tapered optical fiber. Small changes in the refractive index of coating film greatly influence the power of evanescent fields, which modulate the transmission optical power in the waist region. The range of temperature measured is from -20℃ to 70 ℃. The results show that the temperature sensor has high temperature sensitivity (0.012 mW/℃) and good repeatability.展开更多
To find out the effect of the shape of fused taper region on the optical fiber coupler, the fiber couplers were fabricated at different drawing speeds with a six-axes fiber coupler machine. The results, which were obt...To find out the effect of the shape of fused taper region on the optical fiber coupler, the fiber couplers were fabricated at different drawing speeds with a six-axes fiber coupler machine. The results, which were obtained from the shape of fused taper region measured with microscope, show that there is a close correlation between the cone angle and optical performance of fiber coupler. High-performance fiber coupler cannot be obtained until rheological shape is controlled accurately. The numerical analysis model, which was built based on generalized Maxwell viscoelastic theory, is resolved with ANSYS software. The calculated results accord with the experimental data. It can apply a theoretic basis for forecasting the shape of fiber coupler fabricated under the conditions of different technological parameters.展开更多
Through theoretical analysis and experiments, the viscoelastic mechanical model of optical fiber coupler in the process of fused biconical taper was established, and the numerical analysis in non-uniform temperature f...Through theoretical analysis and experiments, the viscoelastic mechanical model of optical fiber coupler in the process of fused biconical taper was established, and the numerical analysis in non-uniform temperature field was made. The results show that the rheological parameters, such as drawing speed and fused temperature, have a tremendous influence on stress distribution and performance of optical fiber coupler, especially the influence of fused temperature. The change of fused temperature by 5℃ can lead to the change of the maximum stress by 30% and stress difference by 20% in the same cross section. The change of temperature gradient by 3% can result in the change of stress difference by 90%. In the present condition of rheological technology, rheological defects such as crystallizations and microcracks are easy to generate in the optical fiber coupler.展开更多
To find out the influence of technological parameters on optical performance of fused optical fiber device, the fiber coupler was served as subject investigated by using the fused biconical taper machining as experime...To find out the influence of technological parameters on optical performance of fused optical fiber device, the fiber coupler was served as subject investigated by using the fused biconical taper machining as experimental setup. Fused fiber coupler's optical performances such as insertion loss, excess loss, directivity and uniformity were tested with the optical test system that was constituted of tunable laser and optical spectrum analyzer. Especially the relationship between optical performance and drawing speed was investigated. The experimental results show that the optical performance is closely related to process conditions. At fused temperature of 1 200 ℃, there exists a drawing speed of 150 μms, which makes the device's performance optimum. Out of this speed region, the optical performance drops quickly. At drawing speed of 200 μms, the excess loss is relatively small when the fused temperature is above 1 200 ℃. So the technological parameters have close relationship with optical performance of the coupler, and the good performance coupler can't get until the drawing speed and fused temperature match accurately.展开更多
To obtain excellent performance optical fiber couplers, the structural difference of SiO2 in couplers with different manufacturing techniques was investigated. With 740-FT-IR infrared spectrometric analyzer, the infra...To obtain excellent performance optical fiber couplers, the structural difference of SiO2 in couplers with different manufacturing techniques was investigated. With 740-FT-IR infrared spectrometric analyzer, the infrared absorption spectrum of SiO2 in couplers at different drawing velocities was measured, and two characteristic peaks in the wavenumber range of 6502000 cm-1 were observed. One characteristic peak is at about 943 cm-1, which is (attributed) to Si—O—Si bond asymmetric stretching vibration, the other is at about 773 cm-1, which is attributed to (Si—O—Si) bond symmetric stretching vibration. From the infrared spectrum, it is found that the intensity and wavenumber of the characteristic peaks are related to the manufacturing technique of couplers. The characteristic peak at (about) 943 cm-1 becomes steeper when increasing the drawing velocity. At the drawing velocity of 150 μm/s, the distance between the two characteristic peaks is maximum, and then the optical fiber coupler has excellent performance, indicating that the performance of the optical fiber coupler has a close relationship with the wavenumber of the two characteristic peaks.展开更多
We demonstrate a stable Yb:fiber frequency comb with supercontinuum generation by using a specially designed tapered single-mode fiber, in which a spectrum spanning from 500 nm to 1500 nm is produced. The carrier-env...We demonstrate a stable Yb:fiber frequency comb with supercontinuum generation by using a specially designed tapered single-mode fiber, in which a spectrum spanning from 500 nm to 1500 nm is produced. The carrier-envelope offset signal of the Yb:fiber comb is measured with a signal-to-noise ratio of more than 40 dB and a linewidth narrower than 120 kHz. The repetition rate and carrier-envelope offset signals are simultaneously phase locked to a microwave reference frequency.展开更多
By stretching the rod waveguide with different velocities in opposite directions,the tapered waveguide can be fabricated.In condition of taking no account of volume expansion caused by heating and under the assumption...By stretching the rod waveguide with different velocities in opposite directions,the tapered waveguide can be fabricated.In condition of taking no account of volume expansion caused by heating and under the assumptions of volume conservation,the rod waveguide can be stretched freely in the heated region without being stretched outside of the heated region. A model,which shows the relation of the transition shape and the two factors,that is the ratio of two velocity and the heated region length,is presented for the shape of the taper transition through mathematic deduction.Based on this model,a desired tapered waveguide can be fabricated.The tapered waveguide are widely used for fabricating tapered fiber couplers and sensors.In addition,the conclusion can be used for fabricating fused fiber coupler.展开更多
A rapid and high-performance sensor for lard adulterant in edible oil was developed using the tapered plastic optical fiber(POF)coated with graphene and multi-walled carbon nanotubes.The coating material was deposited...A rapid and high-performance sensor for lard adulterant in edible oil was developed using the tapered plastic optical fiber(POF)coated with graphene and multi-walled carbon nanotubes.The coating material was deposited onto a tapered POF with a taper waist diameter and a taper length of 0.45 mm and 1 cm,respectively.The addition of the coating material was used to increase the sensitivity and selectivity coefficient of the tapered POF toward the lard substance.The sensing mechanism is based on a simultaneous interaction of lard substance and an evanescent wave of tapered POF with the coating layers.The results showed that graphene coating on the tapered POF increased the selectivity coefficient of the tapered POF towards lard substance from 33.54 to 324.19,and it gave a sensitivity of 0.427 dBm/%.In comparison,multi-walled carbon nanotubes coating increased the selectivity coefficient to 71.65 and increased its sensitivity to 1.189 dBm/%.Thus,the proposed configuration of the tapered POF with the coating material offered a simple configuration for a rapid,high sensitivity and selectivity detection of lard adulterant in edible oils.展开更多
An evanescent wave absorption (EWA) sensor based tapered plastic optical fiber (TPOF) coated with monolayer graphene film for ethanol molecules detection is demonstrated in this study. The continuous and monolayer...An evanescent wave absorption (EWA) sensor based tapered plastic optical fiber (TPOF) coated with monolayer graphene film for ethanol molecules detection is demonstrated in this study. The continuous and monolayer graphene films were grown on a Cu foil by using chemical vapor deposition (CVD) technology. Polymethyl methacrylate (PMMA) was used as the carrier to support the transfer of graphene from Cu foil to the skinless tapered optical fiber core. The accuracy of the TPOF sensor with graphene (G-TPOF sensor) is much higher than that without gra- phene (TPOF sensor), which can be attributed to the molecules enriched on the surface of graphene. The absorbance (A) and the concentrations of ethanol solution show an excellent proportional relationship in a range of 0--100%. The dynamic response of the G-TPOF sensor has shown strong reversibility, repeatability and stability at room temperature. The response time and recovery time of the G-TPOF sensor for different concentrations are all less than 30 s. Beyond that, we selected the Chinese liquor as the analyte, and the results are consistent with the concen- tration-list obtained in the experiment.展开更多
基金funded by Universiti Putra Malaysia through the Geran Inisiatif Putra Siswazah (GP-IPS/2019/9678200)。
文摘Objective: To establish a DNA detection platform based on a tapered optical fiber to detect Leptospira DNA by targeting the leptospiral secY gene.Methods: The biosensor works on the principle of light propagating in the special geometry of the optical fiber tapered from a waist diameter of 125 to 12 μm. The fiber surface was functionalized through a cascade of chemical treatments and the immobilization of a DNA capture probe targeting the secY gene. The presence of the target DNA was determined from the wavelength shift in the optical transmission spectrum.Results: The biosensor demonstrated good sensitivity, detecting Leptospira DNA at 0.001 ng/μL, and was selective for Leptospira DNA without cross-reactivity with non-leptospiral microorganisms. The biosensor specifically detected DNA that was specifically amplified through the loop-mediated isothermal amplification approach.Conclusions: These findings warrant the potential of this platform to be developed as a novel alternative approach to diagnose leptospirosis.
基金Project supported by the Shanghai Leading Academic Discipline Project (Grant No.S30108)the Universities Foster Innovation Foundation Projects for Major Projects in Ministry of Education (Grant No.708041)
文摘A temperature sensor is demonstrated and fabricated by coating the single-mode tapered optical fiber with temperature-sensitive silicone rubber. It works on the change of the evanescent fields in the tapered optical fiber. Small changes in the refractive index of coating film greatly influence the power of evanescent fields, which modulate the transmission optical power in the waist region. The range of temperature measured is from -20℃ to 70 ℃. The results show that the temperature sensor has high temperature sensitivity (0.012 mW/℃) and good repeatability.
基金Project (50605063) supported by the National Natural Science Foundation of ChinaProject(NCET-040753) supported by New Century Excellent Talents in University, ChinaProject (20050533037) supported by the Doctoral Program of Higher Education, China
文摘To find out the effect of the shape of fused taper region on the optical fiber coupler, the fiber couplers were fabricated at different drawing speeds with a six-axes fiber coupler machine. The results, which were obtained from the shape of fused taper region measured with microscope, show that there is a close correlation between the cone angle and optical performance of fiber coupler. High-performance fiber coupler cannot be obtained until rheological shape is controlled accurately. The numerical analysis model, which was built based on generalized Maxwell viscoelastic theory, is resolved with ANSYS software. The calculated results accord with the experimental data. It can apply a theoretic basis for forecasting the shape of fiber coupler fabricated under the conditions of different technological parameters.
基金Project (50235040) supported by the National Natural Science Foundation of China project( NCET-040753) supportedby the New Century Excellent Talent in University project(20050533037) supported by the Doctoral Programof Higher Education
文摘Through theoretical analysis and experiments, the viscoelastic mechanical model of optical fiber coupler in the process of fused biconical taper was established, and the numerical analysis in non-uniform temperature field was made. The results show that the rheological parameters, such as drawing speed and fused temperature, have a tremendous influence on stress distribution and performance of optical fiber coupler, especially the influence of fused temperature. The change of fused temperature by 5℃ can lead to the change of the maximum stress by 30% and stress difference by 20% in the same cross section. The change of temperature gradient by 3% can result in the change of stress difference by 90%. In the present condition of rheological technology, rheological defects such as crystallizations and microcracks are easy to generate in the optical fiber coupler.
基金Project (50605063) supported by the National Natural Science Foundation of ChinaProject(NCET-040753) supported by New Century Excellent Talents in University of ChinaProject (20050533037) supported by the Doctoral Program of Higher Education of China
文摘To find out the influence of technological parameters on optical performance of fused optical fiber device, the fiber coupler was served as subject investigated by using the fused biconical taper machining as experimental setup. Fused fiber coupler's optical performances such as insertion loss, excess loss, directivity and uniformity were tested with the optical test system that was constituted of tunable laser and optical spectrum analyzer. Especially the relationship between optical performance and drawing speed was investigated. The experimental results show that the optical performance is closely related to process conditions. At fused temperature of 1 200 ℃, there exists a drawing speed of 150 μms, which makes the device's performance optimum. Out of this speed region, the optical performance drops quickly. At drawing speed of 200 μms, the excess loss is relatively small when the fused temperature is above 1 200 ℃. So the technological parameters have close relationship with optical performance of the coupler, and the good performance coupler can't get until the drawing speed and fused temperature match accurately.
文摘To obtain excellent performance optical fiber couplers, the structural difference of SiO2 in couplers with different manufacturing techniques was investigated. With 740-FT-IR infrared spectrometric analyzer, the infrared absorption spectrum of SiO2 in couplers at different drawing velocities was measured, and two characteristic peaks in the wavenumber range of 6502000 cm-1 were observed. One characteristic peak is at about 943 cm-1, which is (attributed) to Si—O—Si bond asymmetric stretching vibration, the other is at about 773 cm-1, which is attributed to (Si—O—Si) bond symmetric stretching vibration. From the infrared spectrum, it is found that the intensity and wavenumber of the characteristic peaks are related to the manufacturing technique of couplers. The characteristic peak at (about) 943 cm-1 becomes steeper when increasing the drawing velocity. At the drawing velocity of 150 μm/s, the distance between the two characteristic peaks is maximum, and then the optical fiber coupler has excellent performance, indicating that the performance of the optical fiber coupler has a close relationship with the wavenumber of the two characteristic peaks.
基金supported by the National Basic Research Program of China(973 Program)(Grant No.2012CB821304)the National Natural Science Foundation of China(Grant No.61378040)
文摘We demonstrate a stable Yb:fiber frequency comb with supercontinuum generation by using a specially designed tapered single-mode fiber, in which a spectrum spanning from 500 nm to 1500 nm is produced. The carrier-envelope offset signal of the Yb:fiber comb is measured with a signal-to-noise ratio of more than 40 dB and a linewidth narrower than 120 kHz. The repetition rate and carrier-envelope offset signals are simultaneously phase locked to a microwave reference frequency.
文摘By stretching the rod waveguide with different velocities in opposite directions,the tapered waveguide can be fabricated.In condition of taking no account of volume expansion caused by heating and under the assumptions of volume conservation,the rod waveguide can be stretched freely in the heated region without being stretched outside of the heated region. A model,which shows the relation of the transition shape and the two factors,that is the ratio of two velocity and the heated region length,is presented for the shape of the taper transition through mathematic deduction.Based on this model,a desired tapered waveguide can be fabricated.The tapered waveguide are widely used for fabricating tapered fiber couplers and sensors.In addition,the conclusion can be used for fabricating fused fiber coupler.
基金The research has been funded by the Indonesian Government,KEMENRISTEKDIKTI(Ministry of Research,Technology,and Higher Education of the Republic of Indonesia)for supporting this work under project scheme University’s Fundamental Research Program(Grant No.918/PKS/ITS/2021).
文摘A rapid and high-performance sensor for lard adulterant in edible oil was developed using the tapered plastic optical fiber(POF)coated with graphene and multi-walled carbon nanotubes.The coating material was deposited onto a tapered POF with a taper waist diameter and a taper length of 0.45 mm and 1 cm,respectively.The addition of the coating material was used to increase the sensitivity and selectivity coefficient of the tapered POF toward the lard substance.The sensing mechanism is based on a simultaneous interaction of lard substance and an evanescent wave of tapered POF with the coating layers.The results showed that graphene coating on the tapered POF increased the selectivity coefficient of the tapered POF towards lard substance from 33.54 to 324.19,and it gave a sensitivity of 0.427 dBm/%.In comparison,multi-walled carbon nanotubes coating increased the selectivity coefficient to 71.65 and increased its sensitivity to 1.189 dBm/%.Thus,the proposed configuration of the tapered POF with the coating material offered a simple configuration for a rapid,high sensitivity and selectivity detection of lard adulterant in edible oils.
基金The authors are grateful for financial support from the National Natural Science Foundation of China (Nos. 61205174, 61401258, 11504209, and 11404195), Excellent Young Scholars Research Fund of Shandong Normal University, and Shandong Province Natural Science Foundation (No. ZR2013EMM009).
文摘An evanescent wave absorption (EWA) sensor based tapered plastic optical fiber (TPOF) coated with monolayer graphene film for ethanol molecules detection is demonstrated in this study. The continuous and monolayer graphene films were grown on a Cu foil by using chemical vapor deposition (CVD) technology. Polymethyl methacrylate (PMMA) was used as the carrier to support the transfer of graphene from Cu foil to the skinless tapered optical fiber core. The accuracy of the TPOF sensor with graphene (G-TPOF sensor) is much higher than that without gra- phene (TPOF sensor), which can be attributed to the molecules enriched on the surface of graphene. The absorbance (A) and the concentrations of ethanol solution show an excellent proportional relationship in a range of 0--100%. The dynamic response of the G-TPOF sensor has shown strong reversibility, repeatability and stability at room temperature. The response time and recovery time of the G-TPOF sensor for different concentrations are all less than 30 s. Beyond that, we selected the Chinese liquor as the analyte, and the results are consistent with the concen- tration-list obtained in the experiment.