共查询到19条相似文献,搜索用时 125 毫秒
1.
2.
3.
4.
基于高非线性光纤中SBS效应的慢光系统 总被引:2,自引:2,他引:0
实验研究了高非线性光纤(HNLF)中受激布里渊散射(SBS)的阈值、增益谱、放大特性及其慢光特性,并与普通单模光纤(SMF)进行了对比分析。测量实验表明,HNLF在线宽100MHz的泵浦激光作用下,SBS的阈值为60mW,增益带宽为150MHz,获得的最大慢光延迟量将近15ns,延迟谱与增益谱较好对应。对基于SBS的未来全光通信系统中的高性能光延迟线或全光缓存器具有重要的参考价值。 相似文献
5.
6.
为了研究全波段正常色散光子晶体光纤中高相干度超连续谱的产生及其脉冲压缩,采用分步傅里叶法数值模拟了超短光脉冲在全波段正常色散光子晶体光纤中的非线性传输和超连续谱的产生;利用1阶相干因子分析了抽运波长和入射峰值功率对超连续谱相干特性的影响。结果表明,色散效应越弱,越有利于高相干度超连续谱的产生;在色散效应较小处抽运时,获得了带宽为587nm、平坦度小于7dB的高相干度的超连续谱;超连续谱的相干性越高,越有利于脉冲压缩,采用光栅对压缩器对高相干度超连续谱脉冲进行压缩,获得了8.4fs、压缩质量因子为88.88%的超短光脉冲。因此,抑止色散效应,利用自相位调制可获得高相干度的超连续谱及高质量的脉冲压缩。 相似文献
7.
掺铒光纤放大器(EDFA)具有高增益(40~50 dB)、宽带宽(~50 nm)以及很高的单脉冲饱和能量(~1 μJ),因而被认为是放大超短光脉冲的主要器件。围绕如何减轻光纤非线性效应对超短光脉冲放大过程的有害影响,综述了基于EDFA的超短光脉冲放大技术及其进展情况,介绍了最近的研究结果。 相似文献
8.
9.
10.
提出了一种基于商用化的铌酸锂调制器产生超短光脉冲的方法.直流光依次经过相位调制器和强度调制器调制,利用色散补偿光纤(DCF)和梳状色散光纤链(CDPF)对调制产生的光脉冲分别进行啁啾补偿、非线性压缩.压缩后的光脉冲注入高非线性光纤(HNLF),利用其自相位调制效应(SPM)展开脉冲光谱后滤波,可以有效地消除光脉冲的基座,实现光脉冲的整形.获得了10GHz的1.8ps无基座近变换极限光脉冲. 相似文献
11.
A nonlinear optical loop mirror (NOLM) constructed with linear dispersion decreasing fiber (DDF) is used to compress a beat signal. Several factors impacting on quality of output pulse in this compression system, such as dispersion slope of DDF, power-splitting ratio, incident pulse shape and peak power, are analyzed numerically. The new method for selecting device characteristics is adopted to enable both good pedestal suppression and pulse compression. As a result, the output pulse train with tunable and high repetition rate, pedestal energy of 5.09%, compression ratio of 25.6 and energy transmissivity of 50.56% is obtained by using 0.524 km-long DDF with dispersion slope of 26 ps2/km2 and a coupler with power-splitting ratio of 0.54. 相似文献
12.
In this paper, an optically controlled tunable delay scheme has been proposed using four-wave mixing (FWM) wavelength conversion in a 35-cm highly nonlinear bismuth-oxide fiber (Bi-NLF) together with group velocity dispersion (GVD) in a chirped fiber Bragg grating (CFBG). The Bi-NLF offers a very large nonlinearity and gives rise to significant FWM over a short fiber segment. With the use of a CFBG, a delay range over 185 ps has been experimentally demonstrated. To investigate the performance of the tunable delay, we have applied the scheme for variable delays of 10-Gb/s amplitude-shift keying (ASK) and differential phase-shift keying (DPSK) data signals. The bit error rate (BER) measurements show a power penalty of less than 3.5 dB for both amplitude- and phase-modulated data formats. To further increase the delay time, the CFBG has been replaced by a dispersion compensated fiber (DCF) that provides a wider bandwidth of operation. A variable delay up to 840 ps has been obtained using dual-pump FWM that offers a conversion bandwidth of about 40 nm. The large conversion range helps to minimize GVD-induced pulse distortion as a shorter DCF can be used for a given delay. The Bi-NLF provides an enhanced stimulated Brillouin scattering (SBS) threshold, a reduced latency, and an increased compactness of the approach for practical applications. 相似文献
13.
We demonstrate a multi-wavelength Brillouin-erbium fiber laser (BEFL) with narrow linewidth and tunable wavelength interval using dual-wavelength Brillouin pumping. The generation of multi-wavelength output in BEFL is based on the combination of stimulated Brillouin scattering (SBS) and four-wave mixing (FWM) effect in a fiber cavity. The tunable wavelength interval is determined by the artificially controlled wavelength interval of the pumping lasers. The BEFL could compress a 1 MHz pump laser to a 340 Hz Brillouin Stokes laser, which proves the BEFL has excellent capability of linewidth compression. An erbium-doped fiber pumped by 980 nm laser is inserted into the cavity to further amplify the Brillouin laser. The wideband multi-wavelength BEFL covering over 50 nm is successfully generated when the 980 nm pump power is 400 mW. These features of multi-wavelength BEFL provide an effective method for optical communication systems and optical fiber sensing. 相似文献
14.
报道了一种基于主振荡功率放大(MOPA)结构工作的全光纤窄线宽线偏振纳秒脉冲光纤激光器。脉冲种子源是由一个分布反馈直腔型(DFB)单频光纤激光器被光电调制器进行强度调制后产生的。为了抑制受激布里渊散射(SBS)效应,脉宽被调节为3 ns,并且种子源线宽被相位调制器展宽为2.9 GHz。经两级保偏掺Yb3+光纤放大器放大后,获得了平均功率142 W,重复频率1 MHz,脉冲宽度2.88 ns,峰值功率49.3 kW的脉冲激光输出。在最大输出功率时,激光光束质量因子M2约为1.15,偏振消光比(PER)大于15.4 dB。 相似文献
15.
Hansryd J. Dross F. Westlund M. Andrekson P.A. Knudsen S.N. 《Lightwave Technology, Journal of》2001,19(11):1691-1697
We evaluate numerically and experimentally the stimulated Brillouin scattering (SBS) threshold increase for a short, highly nonlinear GeO2-doped fiber by applying different temperature distributions along the fiber. The temperature coefficient for the Brillouin frequency downshift is measured to 1.2 MHz/°C. A threefold SBS threshold increase is obtained for a 100-m long highly nonlinear fiber with a 140°C temperature gradient. The proposed scheme is implemented in a wavelength converter based on fiber optical four-wave mixing (FWM). The SBS suppression scheme shows negligible influence on the FWM efficiency as well as the wavelength conversion bandwidth. The temperature coefficient for the zero dispersion wavelength is measured to 0.062 nm/°C 相似文献
16.
基于干涉环结构的调Q光纤激光器 总被引:1,自引:0,他引:1
从光纤干涉环中受激瑞利散射(SRS)和光纤中受激布里渊散射(SBS)共同作用调Q的原理出发,研究了光纤干涉环耦合比及环长对调Q光纤激光器输出激光特性的影响。分别采用耦合比为50∶50,80∶20,90∶10的光纤干涉环在不同环长下搭建掺Er3 调Q光纤激光器进行实验。实验结果表明,干涉环的耦合比和环长是影响输出激光特性的关键因素,耦合率(~10%)的干涉环适宜产生脉冲激光,具有高耦合比干涉环的光纤激光器只有连续激光输出;环长根据干涉环耦合率(~10%)在2 m附近调整可以获得理想脉冲激光输出,环长过短时产生输出激光的弛豫振荡,反之产生输出激光脉冲的分裂。采用耦合比为90∶10,环长为2 m的光纤干涉环时,在37 mW的抽运功率下获得脉宽7.2 ns,重复频率212.4 kHz,输出功率5.4 mW的脉冲激光,脉冲波形较好,峰值功率有~30%的波动。 相似文献
17.
采用 2m长 ,10 0 μm纤径单模光纤 ,研究了受激布里渊散射对纳秒激光脉冲的光限幅特性。从耦合波方程出发 ,利用计算机模拟了光纤中瞬态受激布里渊散射过程的光传输特性。理论模拟的能量及光强度的变化规律表明光纤系统对纳秒激光具有很好的光限幅特性。根据理论分析给出所讨论范围内的实验结果 ,实验结果证明此光学系统对纳秒激光脉冲具有光限幅特性及脉宽压缩特性 ,对于输入能量在 10 0~ 4 0 0 μJ变化的纳秒激光脉冲 ,给出输出能量稳定在 6 5~ 85 μJ范围内 ,与理论分析的结论符合得很好 相似文献
18.
锥度光纤作为相位共轭镜具有高反射率、高保真度等优点,将3根自制的、规格不同的锥度光纤相位共轭镜应用在重复频率100Hz,脉宽28ns的激光二极管(LD)抽运的高功率脉冲激光主振荡功率放大器(MOPA)系统中,对其受激布里渊散射(SBS)性能以及锥度区尺寸的影响进行了研究。结果表明,芯径大于400μm的大尺寸锥度光纤可以应用于高功率激光系统中,如选择较长的后端光纤长度以及适当的锥度区规格可获得较高的受激布里渊散射能量反射率和输出能量。在应用总长5.2m,锥度区从φ400μm过渡到φ200μm的锥度光纤时,实验获得了高达85%的受激布里渊散射能量反射率和大于21mJ的双通输出能量,激光脉宽被压缩到17ns,最大峰值功率达到兆瓦量级。 相似文献
19.
Optical phase conjugation (OPC) of multiwavelength signals in a dispersion-shifted fiber (DSF), which can be used for dispersion compensation in the wavelength division multiplexing communication system, is theoretically studied. The multiwavelength phase-conjugate signals are generated by four-wave mixing (FWM) in the dispersion-shifted fiber. There are the pulse-shape distortion and the induced frequency chirping in the phase-conjugate signals owing to pump depletion and the cross-phase modulation among the signals and phase-conjugate signals, respectively. The FWM among the pump wave, signals, and phase-conjugate signals causes unequal conversion efficiencies for the multiwavelength signals and enhances the induced frequency chirping in the phase-conjugate signals. The induced frequency chirping may deteriorate the restoration of the pulse shape. Both the pulse-shape distortion and induced frequency chirping increase with the signal and pump powers. The formula for the induced frequency chirping that is only caused by the signals through cross-phase modulation is derived. The requirement of the signal power in the dispersion-shifted fiber for the restoration of the pulse shape by the optical phase conjugation is estimated and numerically verified 相似文献