共查询到20条相似文献,搜索用时 9 毫秒
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光实时延时技术与相控阵技术的融合,解决了传统相控阵雷达的瞬时大带宽受限和波束偏斜问题.文中给出了光实时延时技术的思想,讨论了光实时延时技术出现的背景.分析了应用于光实时延时技术中的光纤光栅的原理,着重讨论了均匀光纤光栅和线性啁啾光栅,分别给出了基于两种光纤光栅的光实时延时的技术方案,在此基础上,讨论了受控于应变和温度的光纤光栅在光实时延时技术中的应用.最后讨论了一些技术上存在的问题.Abstract: Optical true time delay technology (OTTD) is the key technology for phase array antennas (PAA).By using OTTD,the beam squint and the restriction of instantaneous bandwidth are resolved.The principles of OTTD are given,the emergence background of OTTD is discussed.The theory of fiber Bragg grating(FBG) used in OTTD is analyzed,especially on uniform fiber bragg grating and linear chirped fiber Bragg grating.Two OTTD schemes based on FBG is presented,then some new kinds of FBG used in OTTD are discussed.Some technique hurdles are analyzed as well. 相似文献
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Hao Chi Jianping Yao 《Lightwave Technology, Journal of》2008,26(10):1282-1287
Chirped radio-frequency (RF) pulse generation based on optical spectral shaping and nonlinear wavelength-to-time mapping in a nonlinearly chirped fiber Bragg grating (NLCFBG) is investigated. In the proposed approach, the spectrum of a femtosecond pulse generated by a mode-locked fiber laser is shaped by an optical filter that has a sinusoidal frequency response. The spectrum-shaped optical pulse is sent to the NLCFBG, to implement nonlinear wavelength-to-time mapping. A chirped electrical pulse with the central frequency and chirp rate determined respectively by the first- and second-order dispersions of the NLCFBG is then obtained at the output of a high-speed photodetector. An approximate model that describes the chirped RF pulse generation is derived, which is verified by numerical simulations. Chirped pulse generation with a pulse compression ratio as high as 450 is demonstrated. The key device in the chirped RF pulse generation system is the NLCFBG, which is investigated in detail with an emphasis on the influence of its group delay ripples on the performance of the pulse generation system. Techniques to design and fabricate the NLCFBG are also discussed. The proposed approach provides a potential solution for the generation of chirped RF pulse with a high central frequency and large chirp rate for applications in pulse compression radar systems. 相似文献
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Jianliang Yang Yunqi Liu Sweechuan Tjin Jianping Yao 《Journal of Infrared, Millimeter and Terahertz Waves》2002,23(8):1241-1250
A photonics true-time-delay system for phased array antenna beam steering employing a novel tunable chirped fiber grating delay line and a multi-wavelength erbium-doped fiber ring laser source based on a sampled grating filter is proposed. The tunable chirped fiber grating, which act as a continuous time-delay element, is achieved by bending a uniform fiber Bragg grating bonded at a slant onto the lateral surface of a simply supported beam. This technique allows the dynamic control of the chirp rate and spectral width of the grating without center wavelength shift. By adjusting the chirp rate of the fiber grating via bend strain, this kind of tunable chirped fiber grating could achieve very low and adjustable delay times, therefore provides higher angle resolution for scanning microwave beam, even the wavelengths of laser source are fixed and un-tunable. The true-time-delay system using proposed tunable chirped fiber grating delay element and sampled grating based laser source is constructed and demonstrated experimentally. 相似文献
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Fourier Transform Ultrashort Optical Pulse Shaping Using a Single Chirped Fiber Bragg Grating 总被引:1,自引:0,他引:1
Chao Wang Jianping Yao 《Photonics Technology Letters, IEEE》2009,21(19):1375-1377
Fourier transform ultrashort optical pulse shaping using a single linearly chirped fiber Bragg grating (LCFBG) is proposed and experimentally demonstrated in this letter. The LCFBG in the system performs three functions: temporally stretching the input ultrashort pulse, shaping the pulse spectrum, and temporally compressing the spectrum-shaped pulse. The impulse response of the entire pulse shaping system is equal to the Fourier transform of the square of the grating power reflectivity function. By appropriately designing the grating reflection response, a temporal optical waveform in the subpicosecond regime can be accurately synthesized. An example to show the synthesis of a triangular optical pulse with a full-width at half-maximum of 2 ps is demonstrated. 相似文献
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《Lightwave Technology, Journal of》2009,27(24):5619-5625
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布喇格光栅光纤氢浓度传感器的研究 总被引:2,自引:2,他引:0
提出了一种基于钯涂层布喇格光栅光纤的氢浓度传感器方案。金属钯在氢环境中能够吸收一定量的氢并使其体积膨胀,而布喇格光栅光纤在应力的作用下其有效折射率和周期发生变化,导致中心波长偏移,两者结合可实现对外界环境中氢的测量。建立了外界环境氢浓度同钯涂层布喇格光纤光栅波长偏移之间的关系,通过数值分析给出光栅光纤氢浓度传感器在不同氢浓度以及温度环境中波长偏移量,并分析了其特点。 相似文献
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《Lightwave Technology, Journal of》2009,27(16):3336-3341
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基于叠印啁啾光纤布拉格光栅的宽谱微波光子信道化接收方法 总被引:1,自引:0,他引:1
提出了利用叠印啁啾光纤布拉格光栅(S-CFBG)实现宽谱微波信号光子信道化接收的方法。利用一个S-CFBG产生光频梳(OFC),接收的微波信号被强度调制器调制到OFC的各个载波上。第二个S-CFBG对不同的边带进行滤波,利用波分复用(WDM)解复用器进行信道分离,实现对宽谱微波信号频率的实时测量。该方法还可以同时检测不同射频(RF)载波上所携带的数据信息,无需传统的电本振源阵列,简化了系统结构。建立了测量范围为0~20GHz,测量精度为0.5GHz的宽谱微波信号信道化接收仿真系统。实现了不同RF频率上携带信息的实时同步检测,并对接收误码性能进行了分析。 相似文献
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《Lightwave Technology, Journal of》2008,26(15):2513-2520
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本文将全面分析Chirped Bragg光纤光栅的色散特性,并对色散特性作一定性分析,利用耦合模方程导出ChirpedBragg光栅的反射率方程,从而推导出Chirped Bragg光纤光栅的色散计算公式,然后,引入微波领域的“品质因素”概念,从而量化了色散补偿器的补偿能力。 相似文献
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Kivisto S. Gumenyuk R. Puustinen J. Guina M. Dianov E.M. Okhotnikov O.G. 《Photonics Technology Letters, IEEE》2009,21(9):599-601
We demonstrate a bi-doped fiber laser with dispersion compensation provided by a linearly chirped fiber Bragg grating. Reliable self-starting mode-locking was achieved by using an InGaAsN semiconductor saturable absorber mirror. The all-fiber laser generated short optical pulses with a duration of 1.9 ps at ~ 1165 nm. The large anomalous dispersion of the fiber grating ensured operation in the soliton pulse regime. This in turn enabled us to increase the repetition rate of the output pulse train up to 100.6 MHz via harmonic mode-locking. 相似文献
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ZHANGXiao-guang YULi YANGBo-jun LIUYu-min YUZhong-yuan 《半导体光子学与技术》2003,9(4):209-211,225
A novel tunable chirped fiber Bragg grating technology is proposed and simulated numerically by Matlab. If we adhere a uniform fiber grating with super magnetostrictive film and expose them in a non--uniform magnetic field, the period of the grating can be changed with the strain imposed on it by the magnetostrictive effect . The chirped characteristics can be tuned by changing the magnetic filed which is very flexible indesigning. 相似文献
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