共查询到20条相似文献,搜索用时 0 毫秒
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In this work a self-referencing fiber optic intensity sensor using virtual instrumentation is presented. To ensure higher flexibility and dynamic optimization, the use of an optical fiber delay line or an electrical delay line is avoided by implementing a delay line in the virtual domain, preserving the self-referencing and sensitivity characteristics of the proposed optical intensity sensing structure. Results are presented where displacement is measured with an 18 μm resolution demonstrating the concept feasibility. 相似文献
3.
This paper reports on a novel design of a fiber optic surface plasmon resonance (SPR) sensor based on nanoparticle metal film. The performance of the proposed sensor in terms of its signal-to-noise ratio (SNR) and sensitivity under different conditions related to the film with spherical gold nanoparticles embedded in a host material is theoretically analyzed. In particular, the effect of the parameters such as gold particle size, film thickness, and refractive index of host material is studied and the possible explanation, whenever required, is given. The numerical results presented in this paper leads to fulfill the requirement of significant optimization of the important design parameters to achieve a high SNR and sensitivity of a fiber optic SPR sensor with nanoparticle films. 相似文献
4.
R. M. Lpez V. V. Spirin S. V. Miridonov M. G. Shlyagin G. Beltrn E. A. Kuzin 《Optics & Laser Technology》2002,34(6)
A novel type of distributed fiber optic sensor for petroleum hydrocarbon leak detection and localization based on the measurement of transmitted and Rayleigh backscattered power is presented. The sensor structure includes a sensitive polymer, which reversibly expands in hydrocarbon presence and induces the bending losses in the fiber. The location of the loss region is determined from unique relationships between normalized transmitted and Rayleigh backscattered powers for different positions of the disturbance along the test fiber. The localization of a strong disturbance with an estimated accuracy of ±1 m along a 2.844 km-length single-mode fiber was demonstrated. 相似文献
5.
Pressure and temperature are two important parameters in reservoir engineering. The fiber optic sensors can be used for permanent downhole monitoring. In this paper, we propose an extrinsic fiber Fabry-Perot interferometer (EFPI) sensor for pressure measurement with low sensitivity variation. The pressure sensitivity of EFPI sensor and of the fiber Bragg grating (FBG) sensors have been measured. The experimental pressure sensitivity for EFPI and FBG sensors are measured to be 2.75 × 10−8 1/kPa and 1.52 × 10−8 1/kPa, respectively. The temperature cross-sensitivity problem of the EFPI sensor has been solved by a new technique. The temperature sensitivity of EFPI sensor has been decreased to 1.2 × 10−6/°C, while the temperature sensitivity of non-compensated EFPI sensor has been measured to be 16.4 × 10−6/°C. The results show that the EFPI sensor has a higher pressure sensitivity and good capability to decrease temperature sensitivity in comparison to FBG sensor. 相似文献
6.
U. H. P. Oestreich 《Fiber and Integrated Optics》1982,4(1):95-106
While conventional cable elements can tolerate strains on the order of 1%, optical fibers cannot. As aerial cables may suffer contraction and elongation from low temperatures and high ice or wind loads, or high temperatures, respectively, proper designs have to provide the cables with length margins within which the fibers are protected against mechanical loads, except for a very limited bending stress. The well-suited loose tube buffer design, the way of calculation, and a list of reference cable plants are presented. 相似文献
7.
U. H. P. Oestreich 《Fiber and Integrated Optics》2013,32(1):95-106
While conventional cable elements can tolerate strains on the order of 1%, optical fibers cannot. As aerial cables may suffer contraction and elongation from low temperatures and high ice or wind loads, or high temperatures, respectively, proper designs have to provide the cables with length margins within which the fibers are protected against mechanical loads, except for a very limited bending stress. The well-suited loose tube buffer design, the way of calculation, and a list of reference cable plants are presented. 相似文献
8.
A novel reciprocal Brillouin fiber optic current sensor has been developed and tested. The sensor is based on two counter-propagating
Brillouin lasers circulating in a fiber ring cavity. It shows a sensitivity of 126 Hz/A that is very close to the maximum
sensitivity obtained by using fibers without linear birefringence. The limitations due to the Kerr effect and optical feedbacks
in the system are also investigated. 相似文献
9.
S. Binu V. P. Mahadevan Pillai N. Chandrasekaran 《Optical and Quantum Electronics》2007,39(9):747-752
This paper reports the principle of operation, the design aspects, experimentation and performance of a fibre optic target
reflectivity sensor to examine the correlation between the detector output, variation in material type and the reflectivity
properties of the materials tested. The device consists of a fibre optic transmitter, a fibre optic probe, target and a photodiode
detector. The fibre optic probe consists of two well-polished PMMA (polymethyl methacrylate) fibres cemented together along
some distance over the length. The principle of fibre optic lever displacement sensors is applied. Material effects are examined
by preparing a variety of samples namely gold coated mirror, copper, brass, aluminium, steel and galvanized iron using the
same polishing techniques. It is found that the response of the sensor changes with change of target surface. The results
show that the fibre optic probe is capable of discriminating between materials. With the use of commercially available fibre,
source and detector, the set-up proves to be simple, highly sensitive, low cost and versatile one, which can be adopted for
on-line measurement or inspection of test components. 相似文献
10.
We present a theoretical and experimental investigation of a Sagnac interferometer incorporating a fiber optic recirculating-ring delay line with an erbium-doped fiber amplifier to increase the effective length of the Sagnac loop and thereby improve the low-frequency response. Theoretical calculations show that the low-frequency response of the interferometer is enhanced as expected. However, the noise penalty of using a fiber amplifier in the ring is quite high, especially at low frequencies. The signal-to-noise ratio at low frequencies, using a superfluorescent erbium fiber source, is demonstrated as increasing by a factor of 2 compared to a single-loop Sagnac interferometer with the same total length of fiber, but without fiber amplifier. 相似文献
11.
A fiber optic acoustic emission sensor based on fused-tapered coupler and its applications in structural health monitoring are proposed in this paper. The fiber optic acoustic emission sensor (FOAES) was tested using pencil lead break tests compared with the commercial acoustic emission sensor (R15 PZT). Besides, the sensor was embedded into the carbon fiber reinforced plastics (CFRP) materials and tested in the same way. It successfully detected the AE signals. FOAES was applied in the structural health monitoring (SHM) of CFRP materials. Damages of carbon fiber/epoxy composite laminates during three-point-bending test were monitored by surface-mounted and embedded FOAES, respectively. Results identified that the sensor embedded into composite structures could monitor damage of composite laminates on-line as the surface-mounted sensor did. 相似文献
12.
Fiber optic evanescent field absorption sensor: Effect of fiber parameters and geometry of the probe 总被引:5,自引:0,他引:5
A comparative experimental study of the fiber-optic evanescent field absorption sensor based on straight and U-shaped probes is presented. The effects of numerical aperture and the core radius of the fiber on the sensitivity of the sensor are experimentally investigated. Increase in the numerical aperture of the fiber increases the sensitivity of the sensor in the case of both the probes. The effect of core radius on the sensitivity depends on the bending radius of the probe. In the case of straight probe (i.e. infinite bending radius) the fiber with smaller core radius has high sensitivity while in the case of U-shaped probe with 0.17 cm bending radius, the fiber with larger core radius has high sensitivity. Thus, which fiber (with small or large core radius) has maximum sensitivity depends on the bending radius of the probe. For a given fiber, decrease in the bending radius increases the sensitivity of the U-shaped probe. An inverse power law relationship between the bending radius and the evanescent absorbance and hence the sensitivity is established. 相似文献
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14.
A Jayanth Kumar N M Gowri R Venkateswara Raju G Nirmala B S Bellubbi T Radha Krishna 《Pramana》2006,67(2):383-387
Over the last two decades, the fiber optic technology has passed through many analytical stages. Some commercially available
fiber optic sensors, though in a small way, are being used for automation in mechanical and industrial environments. They
are also used for instrumentation and controls.
In the present work, an intensity-modulated intrinsic fiber optic sugar sensor is presented. This type of sensor, with slight
modification, can be used for on-line determination of the concentration of sugar content in sugarcane juice in sugar industry.
In the present set-up, a plastic fiber made of polymethylmethacrylate is used. A portion of the cladding (1 cm, 2 cm, 3 cm)
at the mid-point along the length of the fiber is removed. This portion is immersed in sugar solution of known concentration
and refractive index. At one end of the fiber an 850 nm source is used and at the other end a power meter is connected. By
varying the concentration of sugar solution, the output power is noted. These studies are made due to the change in refractive
index of the fluid. The device was found to be very sensitive which is free from EMI and shock hazards, stable and repeatable
and they can be remotely interfaced with a computer to give on-line measurements and thus become useful for application in
sugar industries. 相似文献
15.
Norris E. Lewis 《Fiber and Integrated Optics》1992,11(4):337-352
A variety of fiber optic data busses is being developed for aircraft applications. This article addresses five different data busses under consideration for both military and commercial aircraft. The impact of data bus protocol on component design, the effect of data bus topology on power budget and installation issues, and overall data bus performance are discussed. 相似文献
16.
George A. Wilkins 《Fiber and Integrated Optics》2013,32(1):39-62
Abstract Areas for potential use of low-loss optical fibers in undersea communications are discussed, along with constraints that should be satisfied in incorporating these fibers into practical cables. Recent progress in construction of optical cable units with low attenuation, small diameter, low specific gravity, high tensile strength, and extended flexural endurance is described. Design concepts for six undersea optical cables, with a variety of diameters and capabilities, are presented in detail. Guidelines are discussed for the design of such cables. Related operational requirements on the cable, such as power transfer, are examined to show how unconventional approaches can allow advantages of the optical data link to be more fully utilized. 相似文献
17.
Norris E. Lewis 《Fiber and Integrated Optics》2013,32(4):337-352
Abstract A variety of fiber optic data busses is being developed for aircraft applications. This article addresses five different data busses under consideration for both military and commercial aircraft. The impact of data bus protocol on component design, the effect of data bus topology on power budget and installation issues, and overall data bus performance are discussed. 相似文献
18.
WANG Tingyun * SUN Shenghe 《Chinese Journal of Lasers》1998,7(5):407-412
1IntroductionFiberopticringresonators(FORR)havebeeninvestigatedforanumberofyearsforfiberopticdelayelements[1],sensorapplica... 相似文献
19.
George A. Wilkins 《Fiber and Integrated Optics》1977,1(1):39-62
Areas for potential use of low-loss optical fibers in undersea communications are discussed, along with constraints that should be satisfied in incorporating these fibers into practical cables. Recent progress in construction of optical cable units with low attenuation, small diameter, low specific gravity, high tensile strength, and extended flexural endurance is described. Design concepts for six undersea optical cables, with a variety of diameters and capabilities, are presented in detail. Guidelines are discussed for the design of such cables. Related operational requirements on the cable, such as power transfer, are examined to show how unconventional approaches can allow advantages of the optical data link to be more fully utilized. 相似文献
20.
光纤Sagnac温度传感器 总被引:2,自引:0,他引:2
介绍了一种新型的基于光纤Sagnac干涉仪的高精度光纤温度传感器———光纤Sagnac温度传感器。讨论了此传感器的测温原理,推导了被测温度与传感器输出之间的关系,设计并调测了一个具体传感器系统。实验结果表明,此温度传感器具有很高的精度和大的测量范围。 相似文献