Papers by Keyword: Plastic Optical Fiber

Abstract: TiO₂ coated plastic optical fiber is developed for ethanol vapour detection. The detection based on intensity modulated evanescent wave fiber optic sensors. The cladding of POF fiber is etched by using acetone and distilled water. TiO₂ solution is prepared by dissolved the TiO₂ pellet powder in isopropanol and stir it by using ultrasonic homogenizer. The optical properties of TiO₂ is characterized by using UV-Vis spectrophotometer. The performance of coated fiber under ethanol vapour concentration range from 1000 ppm to 5000 ppm is examined. The penetration depth, response of the sensor and the sensitivity of coated fiber is observed transiently. The penetration depth of the TiO₂ coated fiber is 32.96 nm to 35.52 nm with sensitivity of 0.001 µW/% and slope linearity of 93.75 %.

Abstract: Plastic optical fiber sensing that coated with ZnO is developed and its interaction with ethanol and methanol solution is investigated. ZnO is synthesized sonochemically by using the bath type sonicator. The optical properties such as transmittance, absorbance and refractive index of ZnO is determined by using ultraviolet-visible (UV-Vis) spectrophotometer. Then, the cladding of plastic optical fiber (POF) is etched by using acetone solution, sand paper and deionized water. The unclad region is coated with ZnO and being immersed in the solution of ethanol and methanol in the range from 0 v/v% to 50 v/v%. The performance of ZnO coated POF is achieved by obtaining the power output value that transmitted via power meter. The result of this research is as the alcohol concentration increase, the power output value increase. Refractive index of ZnO is varied due to interaction between modified-cladding area and alcohol. Besides that, more light propagates inside the fiber when the sensor is tested under methanol solution compare to ethanol. Thus, the power output ratio increments as well as the sensor efficiency and shows the effectiveness of POF sensor to detect varied alcohol concentration.

Abstract: Plastic materials have many uses. The plastic optical fiber with a low-cost, light weight, good flexibility, big core diameter, easy coupling, anti-electromagnetic interference and electromagnetic radiation, is used for short range communication. This paper analyzed the characteristics of plastic materials and plastic optical fiber, and proposed a novel application technology for access network. In the access network, the plastic optical fiber is used as a transmission medium, from center router to the server, and the various floors of plastic optical fiber switch to the user using plastic optical fiber connections, constitute a plastic optical fiber local area network, to realize the true meaning fiber to the home.

Abstract: Side emitting plastic optical fibers can be used in textile structures for some special optical activities due to the light leaking out from their surface. One significant characteristic of plastic optical fibers is their tendency to weaken side emitting capability under mechanical deformation, which can be simulated as repeated bending cycles under prescribed pretension. The principle of evaluation of flex fatigue was based on the repeated bending cycles until break. Q-Q plot and three-parameter Weibull distribution were used for estimation of numbers of bending cycles of plastic optical fibers with different diameters. The relationship between flex fatigue and flexibility were analyzed and compared with logarithmic values.

Abstract: A new system on demodulation of distributed fiber Bragg grating (FBG) sensor is built which is based on Whispering Gallery Modes Optical Microcavities. In order to eliminate the temperature effect on strian measurement two adjacent FBGs (one for sensing, the other for reference) with similar central wavelength and different lengths as a probe by parallel connection are utilized. Studies have shown that the Whispering Gallery Mode Optical Microcavities with special properties of selecting specific light, when the light couple into the cavity and shocking back and forth, only the specific light can couple out, it can be expressed as: 2πrn = kλ, where r is the cavity radius, n is the refractive index of the cavity, λ is the wavelength of the light coupled out, k is taken a positive integer. Using the fature of Whispering Gallery Modes Optical Microcavities to demodulate the spectral signal of the sensing probe, Combined with the light detector, signal amplifiers, computers and other devices to dispaly the detected strain in real time. Experiment result shows that it is feasible to demodulate action spectrum and the cross of FBG for temperature and the strain is solved. It is testified that the initial establishment of the laboratory system is stable, reliable, and less expensive.

Abstract: An all-acrylic-based 1x2 plastic optical fiber (POF) coupler has been designed and manufactured. The optical device is based on a simple 1x2 Y-branch coupler design with a middle high index contrast waveguide taper and splitting ratio of 50:50. Device modeling has been performed using non-sequential ray tracing with an insertion loss of 4.68 dB. Machining of the optical device has been performed using EGX400 desktop engraver system. 1 mm milling tool size with machine spindle speed of 15,000 rpm has been utilized. A simple optimization on the milling process prior to machining improved the coupling surfaces between the POF fibers and the waveguide taper. POF fibers are inserted into the engraved u-grooves and are passively aligned to the waveguide taper. The measured insertion loss is 7.5 dB and with a splitting ratio of 50:50.

Abstract: A nitro aromatic explosives sensor based on fluorescence quenching was studied in this paper. U-shaped plastic optical fiber was used as sensor head and light emitting conjugated polymer MEH-PPV as fluorescence indictor. The light source was modulated sinusoidal to eliminate the external light disturbance. TNT quenching characteristics of fluorescence intensity were measured; When TNT concentration was lower than 10mg/ml, the relationship between fluorescence intensity and TNT concentration was linearly, when TNT concentration was higher than 10mg/100ml the obtained characteristics showed deviation from linear relation described by Stern-Volmer equation.

Abstract: A high-strain optical fiber sensor system has been developed to provide a cost-effective solution for measurement of very large strain. The measurement of large strain in the order of a few tens of % strain (up to 40 % strain) in geotextile materials has been achieved using an extrinsic plastic optical fiber sensor (POF). Based on this design, the sensor is not limited to operating within the elastic region of the plastic fiber proposed by other workers in the field. The present design allows for compression strains to be measured even after exceeding strain levels of 5% (typical plastic strain values of POFs based on fiber stretching.) The POF were initially calibrated using a linear variable displacement transducer and the results based on tensile tests of a series of geotextile fabrics have shown to compare well with other reference measurements.

Abstract: In this study, photocatalyst-coated glass beads by CVD, N-substituted TiO2 for visible light activation, plastic optical fiber bundle and treated Ti plate were considered as ‘Ecomaterials’ for the potential use in photocatalytic environmental purification system. Each material was carefully prepared and characterized to use in real system either by itself or together for a specific application. The absorption edge of the obtained TiON was ca. 530 nm and the presence of photocatalytic activity of the material under visible light was evidenced.