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含耐高温涂覆层长周期光纤光栅的温度特性研究 总被引:1,自引:1,他引:0
利用逐点写入法在耐高温光纤中用红外飞秒激光直接写入了长周期光纤光栅,研究了光栅的高温温度特性,并做了理论分析.通过对含耐高温涂覆层的长周期光纤光栅进行20 ℃~300 ℃的温度传感实验,结果表明:在高温段光栅的谐振波长漂移量与温度之间仍能保持大的灵敏度(0.060 5 nm/℃)和好的线性度,且光纤耐高温涂覆层不受破坏,光纤耐高温涂覆在高温下不会出现碳化现象,光栅传感性能良好.实验证明该方法制作的光栅适合于长期在高温环境下使用,应用价值巨大. 相似文献
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Fabrication of long-period fiber gratings by focused irradiation of infrared femtosecond laser pulses 总被引:9,自引:0,他引:9
We have fabricated long-period fiber gratings by use of a novel technique using focused irradiation of infrared femtosecond laser pulses. We investigate the thermal stability of the fabricated fiber gratings. The values of the loss peak wavelength and the transmittance of the fiber gratings after heat treatment below 500 degrees C are the same as initial values before heat treatment. The fiber gratings that were fabricated by this technique have a high resistance to thermal decay. We propose that this technique will be useful for fabrication of fiber gratings with a superior aging characteristic. 相似文献
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Fiber optic hydrophones typically use a long sensor fiber wrapped around an air-filled mandrel to achieve high responsivity. Minimum mandrel diameter is determined by fiber reliability considerations. A miniature hydrophone, with diameter of about a third that of previous hydrophones, is reported. Such a hydrophone has applications for very thin towed arrays. Small diameter fiber with high strength Bragg gratings written through the coating are key enablers. 相似文献
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Type I infrared ultrafast laser induced fiber Bragg gratings have been shown to exhibit higher-order resonances related to the Fourier components possessed by their nonsinusoidal index change profile. Using successive higher-order phase masks, we determine the Fourier components of type I-IR gratings in both hydrogen-loaded and unloaded fiber. Knowledge of the relative dc and ac components of a fiber Bragg grating is required for tailoring its spectral response. 相似文献
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Plasmon resonances in gold-coated tilted fiber Bragg gratings 总被引:1,自引:0,他引:1
The transmission spectrum of fiber Bragg gratings with gratings planes tilted at a small angle (2 degrees -10 degrees) relative to the fiber axis shows a large number of narrowband cladding mode resonances within a 100 nm wide spectrum. When a gold coating with a thickness between 10 and 30 nm is deposited on the fiber, the transmission spectrum shows anomalous features for values of the outside medium refractive index between 1.4211 and 1.4499. These features are shown to correspond to the excitation of surface plasmon resonances at the external surface of the gold film. 相似文献
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All-fiber wavemeter and Fourier-transform spectrometer 总被引:1,自引:0,他引:1
An all-fiber Fourier-transform spectrometer is proposed and demonstrated, based on the diffraction of light through the side of a standard optical fiber by a UV-induced fiber grating. The interference pattern, whose Fourier transform yields the optical spectrum, is formed by light diffracted from counterpropagating modes in the fiber. The device is simple and compact and functions as a wavemeter, a fiber-optic network monitor, or a tool for fabrication and testing of long fiber Bragg gratings. 相似文献
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利用啁啾光纤光栅进行色散补偿的研究 总被引:1,自引:0,他引:1
分析了由于光纤的色散引起的脉冲展宽,并介绍了啁啾布拉格光纤光栅进行色散补偿的基本原理。2-5Gb/s、100km 色散补偿的实验结果表明,利用啁啾光纤光栅进行色散补偿是一种切实可行的色散补偿方案。 相似文献
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We report what is to our knowledge the first characterization at high temperatures of long-period fiber gratings written in Ge-free air-silica microstructure fiber. The gratings written with the electric-arc technique suffer a low shift of the resonance wavelengths when the temperature is increased from 20 degrees C to 1200 degrees C. This shift is studied and compared with that of a long-period fiber grating written in a standard single-mode fiber by the same technique. Good thermal stability of the grating and of the fiber after annealing at 1200 degrees C for 1 h is demonstrated. 相似文献
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We present a multiple parameter integrated fiber sensor that can detect vector bending and ambient temperature simultaneously with a single asymmetric multimode fiber Bragg grating. Multimode Bragg gratings were fabricated in an all-silica core fiber by an infrared femtosecond laser, which showed multiple transmission dips in the transmission spectrum. Bending and ambient temperature fluctuations affect the shapes of multiple transmission dips in different ways. In bending, different dips have different sensitivities. On the other hand, temperature fluctuations tended to influence the dips uniformly across different dips. By analyzing the changing spectrum of dips, one can distinguish the changes induced by bending or temperature fluctuations. Furthermore, the high thermal stability of Bragg gratings inscribed by an infrared femtosecond laser can make this double parameter fiber sensor work in very harsh, high-temperature environments. 相似文献
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A new method to tune the peak loss of mechanically formed long-period fiber gratings (MLPFGs) is proposed. Periodic arrayed metal wires are used to obtain the gratings along a single mode fiber (SMF). Self-maintaining gratings are achieved by the bonding force of an UV-adhesive between two glass plates. The initial index modulation formed at room temperature creates a maximum attenuation of −9 dB and −12 dB for coated and uncoated SMF, respectively. By changing the temperature, the peak loss is tuned due to the large thermal expansion of the UV-adhesive. Thermally tunable characteristics caused by the coating layer of the SMF are also described and compared with the results of the device with an uncoated SMF. 相似文献
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The threshold for the fabrication of fiber Bragg gratings with ultrafast 800-nm radiation and a phase mask was studied in SMF-28 and all-silica core fiber by use of 125-fs pulses. High-pressure molecular hydrogen loading (H2 loading) was observed to significantly lower the grating writing threshold in standard Ge-doped telecommunication fiber. No reduction was observed with all-silica core fiber. The index change appeared to be confined to the Ge-doped core region of the fiber. Gratings in H2-loaded SMF-28 had thermal annealing behavior similar to UV-induced gratings. Unlike UV-induced H2-loaded gratings, no absorption associated with Ge-OH defect formation was observed. 相似文献
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Dispersion Compensators Based on Overlaped Linearly Chirped Fiber Gratings for DWDM Systems 总被引:1,自引:0,他引:1
1 Introduction ThereisagreatdealofinterestinfiberBragggratingsduetotheirmanyimportantapplicationsinthefieldoftelecommunicationsandfibersensors .BecausefiberBragggratingsexhibitdispersionbothinreflection ,especiallywhenthe gratingischirped[1] ,andintransm… 相似文献
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By introducing a convergent lens in the phase mask setup and by tilting appropriately the fiber from the phase mask, a linearly chirped fiber grating with an appropriate chirp can be obtained conveniently. Using this method, two groups of fiber gratings, each of them is composed of 8 overlaped linearly chirped fiber gratings but with different center reflection wavelength separations (~0.8 nm and ~1.6 nm, respectively) are fabricated. Experimental results show that, the compensators based on the two groups of fiber gratings can be used to compensate for the dispersion of 8×2.5 Gb/s transmission over 100 km of standard single-mode fiber for multiple channels in optical time-division multiplexing (OTDM) and densed wavelength division multiplexing (DWDM). 相似文献