基于啁啾补偿的自相似脉冲压缩光栅对的设计

为了获取优质的超短脉冲光源,文章将自相似脉冲与光栅对结合,通过数值模拟方法详细分析了自相似脉冲的演化和压缩过程.首先将半高全宽(FWHM)为1 ps、能量为45 pJ的高斯脉冲入射到色散渐减光纤中,产生具有强线性啁啾的自相似脉冲,然后利用光栅对对自相似脉冲进行啁啾补偿压缩,最终得到FWHM为80 fs、峰值功率为507...     

补偿光纤的参数对自相似脉冲压缩效应的影响

从非线性薛定谔（NLS）方程出发,用数值方法研究了在自相似脉冲压缩技术中反常色散补偿光纤的群速度色散参量(GVD参量)和非线性参量对脉冲压缩效应的影响。结果表明,补偿光纤的GVD参量对压缩因子和脉冲峰值功率的影响是周期性的,随着GVD参量数值的增大,脉冲能量按集中-分散-集中的规律周期性变化,且变化周期逐渐增大,一周期内的能量转移加剧;每次能量集中时,脉宽接近压缩极限。最佳光纤长度随着GVD参量数值的增加而下降,但不受非线性参量的影响。另一方面,非线性参量的增大会降低压缩因子,不利于脉冲压缩。通过优化选择补偿光纤参数,能够接近脉宽压缩极限,提高脉冲压缩质量。     

光纤中自相似脉冲研究进展

概述了光纤中自相似脉冲的最新理论与实验研究结果。对稀土元素掺杂光纤放大器、拉曼光纤放大器、光纤激光器、色散渐减光纤中自相似渐进形脉冲的演化特性作了深入细致的描述。并在此基础上对自相似脉冲在光纤通信中的应用作了介绍。展望了自相似脉冲在光纤中的应用前景,并指出了目前研究中有待解决的问题。     

色散渐减光纤中自相似脉冲对的演化和压缩

为了研究了自相似脉冲对在色散渐减光纤中的动力学特性,采用非线性薛定谔方程对脉冲对的演化和压缩特性进行了模拟,分析了脉冲对在演化过程中相邻区域产生的相互作用。结果表明,不考虑3阶色散时,脉冲对在自相似演化过程中,相邻的区域将产生对称性的相互振荡,而脉冲其它区域演化不受影响,通过色散补偿可以得到脉宽为128.4fs、压缩因子为7.8的压缩脉冲对;而在考虑3阶色散时,脉冲对的演化将产生畸变,相邻区域的振荡呈现不对称性,通过色散补偿技术,得到脉宽为211.6fs、压缩因子为4.7的压缩脉冲,虽然不对称性振荡使得压缩脉冲出现较明显的基座,但几乎不影响压缩质量。该研究结果对自相似脉冲对的演化的理解具有参考价值。     

色散渐减光纤中产生优质自相似脉冲的研究

从非线性薛定萼谔(NLS)方程出发,介绍了色散渐减光纤中抛物线脉冲的自相似传输原理以及输出的自相似脉冲的特性.研究不同的g0(色散增益系数)、不同时域包络的初始输入脉冲、不同的初始脉宽对自相似脉冲产生的影响,利用数值模拟结果对色散渐减光纤中影响自相似脉冲形成的参量进行分析,为在色散渐减光纤中产生高质量自相似脉冲的优化设计提供理论依据,发现输入具有较大g0和T0的双曲正割脉冲可以在较短的光纤长度上就获得高功率、强线性啁啾和宽频谱的抛物线型自相似脉冲,同时对自相似脉冲进行补偿时,所需的补偿光纤长度明显缩小,且可得到80fs量级的高质量压缩脉冲.     

啁啾光纤光栅的色散补偿及其理论极限分析

我们给出了一个描述光纤光栅进行色散补偿的模型,另外,还对啁啾光纤光栅补偿能力的理论极限进行了分析。     

无初始啁啾高斯光脉冲的色散展宽及色散补偿

对无初始啁啾高斯脉冲在普通单模光纤中的传输特性及线性啁啾光纤光栅的色散补偿特性进行了理论分析和数值模拟。结果表明,光纤的色散导致了传输脉冲的展宽,线性啁啾光纤光栅能够实现对展宽脉冲的良好补偿,啁啾光栅时延曲线的平滑度和线性度都是影响其色散补偿性能的重要因素。本文对啁啾光纤光栅的制作及其在色散补偿中的应用有一定的指导意义。     

自相似超短脉冲光纤激光器研究进展

概述了自相似孤子光纤激光器研究的最新理论分析和实验结果.论述了由于增益色散的存在,光纤激光器的动力学机制描述和数值计算的理论基础必须用偶合的金斯堡-朗道方程(CGLE),而不是广义非线性薛定谔方程(NLSE).细致地描述了色散管理孤子光纤激光器、耗散孤子光纤激光器、亮-暗孤子光纤激光器、矢量孤子光纤激光器和孤子-自相似...     

色散补偿用啁啾光纤光栅

随着单信道传输速率的提高（10Gb/s、40Gb/s系统)和信号传输带宽的增加，光纤传输系统中的色散问题日益显著，目前的10Gb/s光传输系统中，主要采用色散补偿光纤（DCF）进行色散补偿。DCF具备能实现宽带补偿的优点，但也存在突出的缺点：非线性效应显著；损耗大（为补偿80km的光纤色散需增加8到10dB的附加损耗)，长度随不同的色     

40-GHz transform-limited pulse generation from FM oscillation fiber laser with external cavity chirp compensation

A 40-GHz frequency modulation oscillation fiber laser is demonstrated and the continuous-wave (CW) output is used for generating a high repetition rate short pulse train by external cavity chirp compensation. A 1.37-ps transform-limited pulse is obtained from its chirped, 488.1-GHz width CW output.     

啁啾对存在离散效应时孤子脉冲压缩的影响

本文从描述双皮秒脉冲在单模光纤中共同传输的耦合NLS方程出发 ,研究了具有啁啾因子的泵浦脉冲对孤子脉冲压缩的影响 ,结果表明 :泵浦脉冲具有初始啁啾时 ,会有利于存在离散效应和初始延时的信号脉冲的压缩 ,脉冲的压缩比随着正啁啾因子的增加而缓慢增加 ,负啁啾因子则相反     

损耗和啁啾对皮秒脉冲孤子效应压缩的影响

在计及光纤损耗的前提下,近似求解非线性薛定谔方程,分析了单模光纤的负群速度色散区群速度色散(GVD)和自相位调制(SPM)对啁啾脉冲的作用,定量计算光纤损耗和初始正啁啾对皮秒脉冲孤子效应压缩的影响。结果表明,初始正啁啾改善了损耗对压缩参量的不良影响,遏制了最佳光纤长度的增加。若选取适当的光纤长度和初始峰值功率,可以实现正啁啾脉冲在单模光纤中的有效压缩。     

Programmable chirp compensation for 6-fs pulse generation with aprism-pair-formed pulse shaper

We describe a TF5 prism-pair-formed pulse shaper for programmable pulse chirp compensation. The advantages of this kind of pulse shaper are: (1) very broad bandwidth of transmission; (2) smaller losses; and (3) no requirement for a large-size spatial light modulator (SLM) if the input spectrum is very broad. In our experiment, an ultrabroad spectral (500-1000 nm) pulse is produced by launching 1-kHz, 30-fs, 400-μJ pulses at 780 nm into an argon filled glass capillary fiber at the gas pressure of 2.0 bar. The fiber has an inner diameter of 140 μm and a length of 60 cm. The chirped pulse is first precompressed by a pair of BK7 prisms with a separation length of 65 cm and then directed into the prism-pair-formed pulse-shaping apparatus with a 128-pixel SLM, which provides quadratic and cubic phase compensation. When the quadratic and cubic phases are -330 fs² and +2000 fs³, respectively, at the wavelength of 760 nm, an ultrashort optical pulse of 6 fs (FWHM) is generated. This is, to the best of our knowledge, the shortest optical pulse ever compressed using the SLM pulse-shaping technique     

基于色散渐减光纤的光脉冲压缩技术及其进展

综述了基于色散渐减光纤的绝热孤子压缩、高阶孤子压缩和非线性光纤环镜的光脉冲压缩的方法、原理及其进展,介绍了作者最近的研究成果,即采用色散渐减光纤构成的马赫--曾德尔干涉仪压缩光脉冲.     

脉冲形状对半导体激光放大器用于啁啾补偿的影响

光脉冲经过增益饱和的行波半导体激光放大器后,由于放大器的自相位调制,使放大脉冲附加上频率啁啾。合适的附加啁啾不但能抵销入射脉冲的初始啁啾,而且还有可能借助简单的群速度延迟线对脉冲进行压缩。本文计算了不同形状的入射脉冲经光放大器放大后的输出脉冲形状及其附加的频率啁啾,分析了它们对光放大器用于啁啾补偿的影响。     

Optical pulse compression based on stationary rescaled pulse propagation in a comblike profiled fiber

In this paper, optical pulse compression using a comblike profiled fiber (CPF) is theoretically and experimentally studied, in which highly nonlinear fibers and single-mode fibers are alternately concatenated. Stationary rescaled pulse (SRP), is the main focus, which is a recently discovered nonlinear stationary pulse in CPF. The fundamental characteristics of SRP are investigated, and SRP propagation is applied to the design of the CPF pulse compressor. Using the proposed design method, the specifications of the CPF can easily be controlled, such as the compression ratio per step of the CPF or the pedestal of the output pulse. Two experimental results of pulse compression using the CPF based on the proposed design method are shown: 1) pulse compression with a large compression ratio per step of the CPF and 2) low-pedestal and wideband wavelength-tunable compression. A parametric noise-amplification phenomenon occurring in a compression process for an optical pulse sequence is also numerically analyzed.     

基于FPGA的雷达脉冲压缩系统设计

脉冲压缩技术是指对雷达发射的宽脉冲信号进行调制(如线性调频、非线性调频、相位编码),并在接收端对回波宽脉冲信号进行脉冲压缩处理后得到窄脉冲的实现过程.脉冲压缩有效地解决了雷达作用距离与距离分辨率之间的矛盾,可以在保证雷达在一定作用距离下提高距离分辨率.     

Thermal compensation for a chirp fiber Bragg grating bonded substrate

The chirp fiber bragg grating (CFBG) created using the substrate-straining technique requires an invariable center wavelength when subjected to a temperature change. To accomplish this task, a secondary substrate is attached to one side of the main substrate in a bimetallic beam configuration, used as a thermal compensator. However, when the temperature changes, the strain along the CFBG is not uniform because the main substrate is not prismatic. A systematic method based on the shape optimization technique was developed to determine the geometry of the second substrate for temperature compensation. The results show that the second substrate, determined using shape optimization, can produce the required strain distribution to compensate for the center wavelength shift in a CFBG due to temperature changes. Although the thermal compensation of a CFBG demonstrated here is simple, it should be emphasized that this methodology can be easily applied to determine the substrate profile for thermal compensation in other FBG-bonded substrates with nonuniform cross sections.