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1.
Bias thermal stability of a fiber-optic gyroscope using polarization-maintaining photonic crystal (PM-PCF) was studied. The thermal sensitivity of birefringence in PM-PCF and polarization cross talking in fiber coil was measured. Using an OCDP method, the polarization cross talking causing phase error of the fiber-optic gyroscope (FOG) was analyzed. The contrast experiment result of the FOGs with the PM-PCF coil and PMF coil showed that using PM-PCF instead of PMF can improve the FOG’s bias thermal stability by about 50 %. 相似文献
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Effect of radiation-induced mean wavelength shift in optical fibers on the scale factor of interferometric fiber optic gyroscope at a wavelength of 1300 nm 下载免费PDF全文
In order to analyze the effect of wavelength-dependent radiation-induced attenuation (RIA) on the mean transmission wavelength in optical fiber and the scale factor of interferometric fiber optic gyroscopes (IFOGs), three types of polarization-maintaining (PM) fibers is tested by using a 60Co γ -radiation source. The observed different mean wavelength shift (MWS) behaviors for different fibers are interpreted by color-center theory involving dose rate-dependent absorption bands in ultraviolet and visible range and total dose-dependent near infrared absorption bands. To evaluate the mean wavelength variation in fiber coil and the induced scale factor change for space-borne IFOG under low radiation dose in space environment, the influence of dose rate on the mean wavelength is investigated by testing four germanium (Ge) doped fibers and two germanium-phosphorus (Ge-P) codoped fibers irradiated at different dose rates. Experimental results indicate that the Ge-doped fibers show the least mean wavelength shift during irradiation and their mean wavelength of optical signal transmitting in fibers will shift to shorter wavelength in low-dose-rate radiation environment. Finally, the change in the scale factor of IFOG resulting from the mean wavelength shift is estimated and tested, and it is found that the significant radiation-induced scale factor variation must be considered during the design of space-borne IFOG. 相似文献
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Effect of radiation-induced mean wavelength shift in optical fibers on the scale factor of an interferometric fiber optic gyroscope at a wavelength of 1300 nm 下载免费PDF全文
In order to analyze the effect of wavelength-dependent radiation-induced attenuation (RIA) on the mean trans- mission wavelength in optical fiber and the scale factor of interferometric fiber optic gyroscopes (IFOGs), three types of polarization-maintaining (PM) fibers are tested by using a 60 Co γ-radiation source. The observed different mean wave- length shift (MWS) behaviors for different fibers are interpreted by color-center theory involving dose rate-dependent absorption bands in ultraviolet and visible ranges and total dose-dependent near-infrared absorption bands. To evaluate the mean wavelength variation in a fiber coil and the induced scale factor change for space-borne IFOGs under low radiation doses in a space environment, the influence of dose rate on the mean wavelength is investigated by testing four germanium (Ge) doped fibers and two germanium-phosphorus (Ge-P) codoped fibers irradiated at different dose rates. Experimental results indicate that the Ge-doped fibers show the least mean wavelength shift during irradiation and their mean wavelength of optical signal transmission in fibers will shift to a shorter wavelength in a low-dose-rate radiation environment. Finally, the change in the scale factor of IFOG resulting from the mean wavelength shift is estimated and tested, and it is found that the significant radiation-induced scale factor variation must be considered during the design of space-borne IFOGs. 相似文献
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Stable Dual-Wavelength Fibre Laser with Bragg Gratings Fabricated in a Polarization-Maintaining Erbium-Doped Fibre 总被引:1,自引:0,他引:1 下载免费PDF全文
A new polarization-independent duai-wavelength fibre laser by fabricating a uniform FBG and a chirped FBG in a polarization-maintaining erbium-doped fibre (PM-EDF) is proposed and demonstrated. The wavelength spacing is 0.18nm and the optical signal-to-noise ratio is greater than 50dB with pump power of 246mW. Chirped FBG is used to make the reflectivity wavelengths of two PM-FBGs match easier. Since both EDF and FBGs are polarization-maintaining without splices and the two wavelengths are polarization-independent, the maximum amplitude variation and wavelength shifts for both lasing wavelength with 3-min intervals over a period of six hours are less than 0.2 dB and 0.005 nm, respectively, which shows stable dual-wavelength output. 相似文献
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Flat Supercontinuum Generation at 1550 nm in a Dispersion-Flattened Microstructure Fibre Using Picosecond Pulse 下载免费PDF全文
The generation of a flat supercontinuum of over 80nm in the 1550nm region by injecting 1.6ps 10 GHz repetition rate optical pulses into an 80-m-long dispersion-flattened microstructure fibre is demonstrated. The fibre has small normal dispersion with a variation smaller than 1.5 (ps·nm^-1·km^-1) between 1500 and 1650nm. The generated supercontinuum ranging from 1513 to 1591 nm has the flatness of ±1.5 dB and it is not so flat in the range of several nanometres around the pump wavelength 1552nm. Numerical simulation is also used to study the effect of optical loss, fibre parameters and pumping conditions on supercontinuum generation in the dispersion-flattened microstructure fibre, and can be used for further optimization to generate flat broad spectra. 相似文献
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Highly Er3+ /yb3+-codoped single-mode phosphate glass fibre is fabricated by the rod-in-tube technique. The performances of high-concentration Er3+ /yb3+-codoped phosphate glass fibre amplifiers are investigated and discussed. An efficient optical fibre amplifier with a gain of 12.6 dB based on a 3.0 cm long Era+ /ybe+-codoped phosphate glass fibre is demonstrated under a dual-pump configuration with two 976 nm fibre-pigtail laser diodes, which make it attractive for compact Er3+-doped fibre amplifiers. The obtedned noise figures of signal wavelength from 1525 to 1565nm are less than 6.0dB. Gain saturation behaviour at 1535nm is also investigated, and the obtained saturation output power is larger than 10 dBm. 相似文献
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Superfluorescent fiber source (SFS) is generally considered to be promising in optical sensing. In this paper, the gamma radiation effect on the double pass backward (DPB) SFS was investigated. Firstly, a sample of DPB SFS together with a 9 m Er-doped fiber (EDF) was irradiated by 60Co source with radiation dose rate of 3.6 Gy/h and total dose of 200 Gy. And the results were analyzed to find that at the very start of radiation the RIL of the sampled Er-doped fiber was greater than that of sampled SFS while at about 100 Gy the RIL slope of the EDF became less than that of the SFS. Above all, the loss from EDF was dominant to that from the SFS in gamma radiation environment. Mean wavelength of the SFS drifted about 4 nm mainly caused by the radiation loss. In the end, the potential influence to FOGs in space applications was simulated. 相似文献
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Characteristics of Cladding-Pumped Short Er3+/Yb3+ Codoped Single Mode Phosphate Glass Fibre 下载免费PDF全文
XU Shan-Hui YANG Zhong-Min XU Wen-Cheng QIU Dong-Lai ZHANG Qin-Yuan JIANG Zhong-Hong 《中国物理快报》2009,26(1)
We experimentally investigate the laser characteristics of a series of short pieces of newly-developed Er3+/Yb3+ codoped single mode phosphate glass fibres via the cladding pump of a 976nm multimode laser diode. A stablecontinuous-wave single transverse mode laser with over 85mW at 1553nm is generated from a 5.5-cm-long active fibre. Single mode laser output power per unit length is up to 15mW/cm. Moreover, the slope efficiency is 11.8% when the pump power is below 940mW and the 3dB linewidth is 0.06nm at the maximum pump power. The numerical simulation results show that the laser emission slope efficiency can exceed 20% by means of increasing the coupling efficiency of the pump to the fibre core further. 相似文献
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Birefringence of a microstructure fibre with irregular structures is investigated using the finite element method. The birefringence of each sample is statistically analysed, and the relation between the birefringence and the irregular structure of the microstructure fibre is derived. The results indicate that the irregular structure of the symmetrical microstructure fibre result in the birefringence which is more strongly affected by disorder of air holes than the nonuniformity. Moreover, lower birefringence can be obtained with smaller air holes and larger pitch in the fibre structure. 相似文献
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To analyze the bias error in the optical path of closed-loop polarization-maintaining (PM) fiber optical gyroscope (FOG), the interference signal term carrying only Sagnac phase shift in phase is divided into two types: one generated by interference between main wave-trains in the clock-wise (CW) direction and counter clock-wise (CCW) direction, and the other one generated by interference between secondary wave-trains in the CW and CCW direction. The residual term is discovered in the second kind, which is caused by synthetic effect of broad-spectrum source and birefringence effect in a FOG with the existence of crossovers. The main influencing factors and the effect on FOG performance of the bias error generated by the residual term is analyzed, and its suppression measures are promoted. Simulation result demonstrates that the bias error can be suppressed from about 0.02°/h to less than 2×10−4°/h at room temperature and its peak to peak value of variation with temperature can be suppressed to less than 4×10−4°/h, through matching birefringent fiber length and increasing the delay between modes of light source, which is small enough to meet the requirement of FOG with high performance. 相似文献
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Total ionizing dose effects of Si^+ ion implanted thermal oxides are studied by 10keV x-ray irradiation. Photoluminescence (PL) method is engaged to investigate nanostructures of samples. Ar^+ implanted samples are also studied by the same way to provide a comparison. The results show that Si^+ implantation following with high temperature annealing can significantly reduce the radiation induced flatband shift, which is caused by net posi- tive charge accumulation in oxides. This reduction is attributed to the formation of Si nanoscale structures. Ar^+ implantation is also found to reduce the radiation induced flatband shift, while it is different that the reduction with Si^+ implantation shows little dependence on implant dose of Ar^+ ions. This is explained by possible increase of recombination centres. 相似文献
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根据光纤陀螺输出信号的特点和应用环境的要求,在Mallat小波变换的基础上,研究了一种多算法融合的实时滤波算法.该算法在光纤陀螺刚启动,数据量偏少时,通过IIR滤波器进行滤波|采样数据量足够多时,通过施加滑动数据窗来实现小波实时去噪,采用周期对称延拓的方法去除小波去噪的边界问题,可有效去除光纤陀螺输出信号中高频部分的噪音,提高滤波效果,抑制陀螺的随机漂移.通过实验验证了该方法对陀螺输出信号进行滤波的可行性和有效性. 相似文献
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In this letter, we reported on a polarization-maintaining photonic crystal fiber (PM-PCF) with near-circular mode field distribution. The modal field distribution of the proposed PM-PCF is near-circular, which enhanced the mode field compatibility between PM-PCFs and traditional polarization-maintaining fibers (PMFs). And the birefringence of the novel PM-PCF can easily achieve the order of 10−3–10−2, which is at least 1–2 order of magnitude higher than that of commonly used Panda or Bow-tie PMFs. Additionally, the diameter of this PM-PCF is much smaller than traditional PM-PCFs. It can well satisfy the application of fiber optic gyroscope (FOG) which need high polarization-maintaining, high-precision and miniaturization. 相似文献
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MEN Zhi-Wei FANG Wen-Hui SUN Xiu-Ping LI Zuo-Wei YI Han-Wei WANG Zhao-Min GAO Shu-Qin LU Guo-Hui 《中国物理快报》2008,25(11):3999-4002
One piece of single-mode silica fibre is used to study of temperature characteristics of stimulated Raman scattering (SRS), additional peaks (double-humped) are observed at both sides of pump light and 1st-order Stokes light in the experiment. The frequency shift of the double-humped is calculated by stimulated Four--Photon mixing (SFPM) phase matching theory, the result is consistent with the frequency shift of this experiment. Simultaneously, the experimental conditions accord with the theoretical calculation of effective coherence length. We indicate that the double-humped phenomenon is caused by SFPM. The intensity of double-humped is first increased, then decreased and finally disappeared as the temperature increases. This phenomenon has been explained theoretically. 相似文献
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Space radiation effect on fibre optical gyroscope control circuit and compensation algorithm 下载免费PDF全文
The process of a γ-irradiation experiment of fibre optical gyroscope (FOG) control circuit was described, in which it is demonstrated that the FOG control circuit, except for D/A converter, could endure the dose of 10krad with the protection of cabin material. The distortion and drift in D/A converter due to radiation, which affect the performance of FOG seriously, was indicated based on the elemental analysis. Finally, a compensation network based on adaptive neuro-fuzzy inference system is proposed and its function is verified by simulation. 相似文献
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The optic-bound effect on fibre optic gyro (FOG) precision is
analysed theoretically, and formulas describing the change of FOG
light power under the action of optic-bound effect are given. It is
confirmed that optic-bound effect is a main instantaneous
non-reciprocity effect of FOG in addition to the Sagnac effect and
can lead to a dynamic error of FOG in practical environments. An
approach to suppressing or eliminating the error due to the
optic-bound effect is presented and verified experimentally. The
result shows that the approach is valid and the precision of FOG is
improved observably. 相似文献
19.
Study on Background Radiation at Beijing Electron Positron Collider and Radiation Damage of High-Z Scintillation Crystals 下载免费PDF全文
CHEN Yu DAI Chang-Jiang GU Yi-Fan LEI Zhuan-Heng LI Jian-Ping LIU Shu-Dong SHAO Bei-Bei TANG Yue-Li 《中国物理C(英文版)》1993,17(8):673-679
A systematic study of radiation backgrounds in the interaction region at the Beijing e+e- Collider BEPC is carried out for the first time to the needs of particle physics experiment.An effective method to study dynamically the radiation environment of the collider is successfully developed which allows the measurement of the instantaneous radiation dose rate and is distribution for different beam conditions and as a function of time during a quiet luminosity run.The radiation sensitivity of domestic BGO and BaF2 crystals in the BEPC environment is examined. 相似文献
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A Novel Method to Calculate the Initial Phase Difference between the Two Fibre Arms of Laser Homodyne Iuterferometer 下载免费PDF全文
We suggest a novel method to calculate the initial phase difference between two fibre arms of a laser homodyne interferometer. Put the two fibre arms in a temperature controller, whose short term stability is 0.02° C (measured in an hour), then measure the interference photocurrent and the photocurrents from the two fibre arms at a fixed temperature. With these three photocurrents we can calculate the value of the initial phase difference. We set up a simple laser homodyne interferometer to test the theory. The experimental results are repeatable and the measurement precision is about 0.04°. It is theoretically and experimentally proven that this method is potentially easy and practical. 相似文献