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Extended range interrogation of wavelength division multiplexed fibre Bragg grating sensors using arrayed waveguide grating 总被引:1,自引:0,他引:1
A technique for interrogating multiplexed fibre Bragg grating (FBG) sensors using an arrayed waveguide grating (AWG) is described. The approach considerably extends the sensing range from that achieved previously, while providing a strain resolution of 17n/spl epsiv///spl radic/Hz at 30 Hz. 相似文献
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Canning J. Jackson S.D. Aslund M. Groothoff N. Ashton B. Lyytikainen K. 《Electronics letters》2005,41(20):1103-1104
An air-clad fibre laser using a Bragg grating written directly into the Yb/sup 3+/ doped core as the end reflector is presented. For an unsaturated output power of 12 W and slope efficiency of 34%, there is a saturated laser wavelength shift of approximately 0.4 nm. 相似文献
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The use of gratings written in tin-doped silica fibres as a thermometer for high-temperature applications is described. Measurements up to ~800°C show a significant advantage over conventional fibre gratings. A considerable blue-shift has been observed at high temperatures. If corrections for blue-shift are taken into account, the errors are smaller than ~2°C 相似文献
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In this paper, a new type of multi-wavelength fiber laser is proposed and demonstrated experimentally. Superimposed fiber grating (SIFG) and chirp fiber Bragg grating (CFBG) are used for wavelength selection. Based on gain equalization technology, by finely adjusting the stress device in the cavity, the gain and loss are equal, so as to suppress the modal competition and achieve multi-wavelength lasing at room temperature. The experimental results show that the laser can output stable multi-wavelength lasers simultaneously. The laser coupling loss is small, the structure is simple, and it is convenient for integration, so it can be widely used in dense wavelength division multiplexing (DWDM) system and optical fiber sensors. 相似文献
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A new technique based on two low-finesse fibre Bragg grating Fabry-Perot interferometers to study photosensitivity in optical fibre is presented. Phase evaluation using the Fourier spectra allows precise determination of the evolution of the refractive index with accumulated fluence. Results are given for different germanium/boron codoped fibres and for hydrogen-loaded fibres. 相似文献
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A Sagnac fiber interferometer with the population grating formed in saturable erbium-doped fiber (EDF) for fiber Bragg grating (FBG) dynamic strain sensing is proposed. In this configuration, a semiconductor optical amplifier (SOA)-based fiber ring laser with an FBG reflector is employed in the sensing part and a Sagnac interferometer based on transient two-wave mixing (TWM) via dynamic population gratings in single-mode polarization maintaining erbium-doped fiber (PM-EDF) is used in this detecting part. Experimental results show that the Sagnac fiber interferometer detection system can stably respond to dynamic strains at high frequencies. As an example of application, the response of the sensor system to continuous sinusoidal ultrasonic signals is presented. The proposed simple and robust configuration has an all-fiber design based on commercially available elements, which makes it promising for applications in fiber optic ultrasonic sensors. 相似文献
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Iocco A. Limberger H.G. Salathe R.P. Everall L.A. Chisholm K.E. Williams J.A.R. Bennion I. 《Lightwave Technology, Journal of》1999,17(7):1217-1221
A Bragg grating fast tunable filter prototype working over a linear tuning range of 45 nm with a maximum tuning speed of 21 nm/ms has been realized. The tunable filter system is based on two piezoelectric stack actuators moving a mechanical device thus compressing an apodized fiber Bragg grating. The filter allows both traction and compression and can work in transmission and in reflection. It is designed to work with a channel spacing of 100 GHz according to the ITU specifications for wavelength division multiplexing systems 相似文献
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A novel high-speed fibre Bragg grating (FBG) sensor interrogator using dispersion-compensating fibre is proposed and demonstrated. The wavelength shift measurement of the FBG sensor is converted to time-domain measurement. The high-speed potential of this scheme was investigated experimentally, demonstrating an effective sampling speed of 2.44 megasamples per second. 相似文献
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Frequency noise of a Bragg grating fibre laser 总被引:1,自引:0,他引:1
The measured frequency noise spectrum of a pair of single-frequency Bragg grating fibre lasers is dominated by noise at audio frequencies peaked near 700 Hz which fades into a white noise floor above ~50 kHz. The measured white noise floor yields an estimated Lorentzian FWHM linewidth of ~61 Hz 相似文献
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The excitation of gap solitons in a 30 cm fibre Bragg grating using 0.68 ns pulses, which emerge with atunable delay of up to 3.2 ns, corresponding to almost five pulse widths, and without broadening, are observed. This delay is an improvement by a factor of 2 from previous experiments. 相似文献
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Electrically tunable dispersion compensator with fixed center wavelength using fiber Bragg grating 总被引:1,自引:0,他引:1
Ngo N.Q. Li S.Y. Zheng R.T. Tjin S.C. Shum P. 《Lightwave Technology, Journal of》2003,21(6):1568-1575
We present the design and development of a novel tunable dispersion compensator with fixed center wavelength that is based on the electrical adjustment of the chirp of a fiber Bragg grating (FBG). Both temperature gradient and strain gradient are employed to adjust the chirp of the FBG jointly. The electrical current flowing through the taper on-fiber thin-film heater will introduce a temperature gradient on the FBG. The shrinkage of a negative thermal expansion coefficient (NTEC) ceramic due to the temperature rise will compress the tapered FBG mounted inside it, and this will introduce a strain gradient on the FBG. The center wavelength of the FBG will be kept fixed because the effect of temperature rise on the FBG and the effect of compression of the FBG will offset each other. Applying an electrical power of less than 0.68 W, we demonstrate a linearly chirped FBG whose dispersion can be continuously adjusted from -178 ps/nm to -302 ps/nm with a central wavelength shift of as small as 0.16 nm. 相似文献
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Gwandu B.A.L. Zhang W. Williams J.A.R. Zhang L. Bennion I. 《Electronics letters》2002,38(22):1328-1330
Microwave photonic filtering is realised using a superstructured fibre Bragg grating. The time delay of the optical taps is precisely controlled by the grating characteristics and fibre dispersion. A bandpass response with a rejection level of >45 dB is achieved. 相似文献
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《Electronics letters》2006,42(1):14
Presented is a technique for the continuous tracking of interferometer fringes. The technique uses a fringe quadrature signal to keep the state of the digital tracker in balance with the interferometer state. The quadrature signal is obtained through wavelength modulation of a semiconductor laser 相似文献
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Tunable multi-wavelength Raman fibre laser based on fibre Bragg grating cavity with PMF Lyot-Sagnac filter 总被引:1,自引:0,他引:1
A flexibly-tunable multi-wavelength Raman fibre laser based on the polarisation maintaining fibre (PMF) Lyot-Sagnac filter after composing fibre Bragg grating cavity is demonstrated experimentally. The number of channels and wavelength spacing of the Raman laser can be controlled readily by /spl Delta/n /spl middot/ L products of PMF segments in the intracavity PMF Lyot-Sagnac filter. 相似文献
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由于各种光噪声的影响,基于可调谐法布里-珀罗(F-P)滤波器的光栅解调仪解调精度不够高,光路噪声通常会带来10pm量级的波长测量误差。为了提高布喇格波长检测精度,采用了在解调过程中对光纤光栅反射谱进行高斯拟合,从而消减噪声影响的方法。实验发现,拟合后中心波长的测量误差小于2.5pm,温度测量值与实际温度之间的标准方差为0.3℃。结果表明,在有害噪声信号不是非常大的情况下,该方法能有效提高波长检测精度。 相似文献
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Fast optical wavelength interrogator employing arrayed waveguide grating for distributed fiber Bragg grating sensors 总被引:14,自引:0,他引:14
A new type of interrogator for distributed fiber Bragg grating (FBG) sensors that employs an arrayed waveguide grating (AWG) is proposed and its operating features are in detail investigated both theoretically and experimentally. The remedy for achieving the linear characteristics of wavelength detection as well as for insuring the reliable and environmentally stable operation of interrogation is proposed and its usefulness is demonstrated in good agreement with the experimental results. The developed interrogator consists of a fully passive, small, all-solid, rugged optical IC and can detect wavelengths of a great number of FBG sensors with high precision better than 0.5 pm and high speed. 相似文献
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A novel interrogation technique for fibre Bragg gratings, based on the self-mixing effect in strong feedback regime and intensity detection, is demonstrated through experimental measurements. The application of an appropriate spectral estimator permits transferring the analysis into the frequency domain, leading to the realisation of a power drift-tolerant strain sensor. 相似文献