共查询到20条相似文献,搜索用时 23 毫秒
1.
Optimization and fabrication of stitched long-period gratings for gain flattening of ultrawide-band EDFAs 总被引:1,自引:0,他引:1
Zhang A.P. Xue-Wen Chen Jin-Hua Yan Zu-Guang Guan Sailing He Hwa-Yaw Tam 《Photonics Technology Letters, IEEE》2005,17(12):2559-2561
We present the optimization and fabrication of the stitched long-period fiber gratings (SLPGs) for gain flattening of an ultrawide-band erbium-doped fiber amplifier (EDFA). With an improved genetic algorithm, the gain spectrum of a practical EDFA with bandwidth of 80 nm is flattened within /spl plusmn/0.69 dB by an optimized SLPG. Furthermore, the SLPG is designed specially for a point-by-point grating writing technique. A superior control of the fabrication procedure of the designed SLPG has been demonstrated in the experiment. 相似文献
2.
介绍了一种利用机械应力在普通单模光纤(SMF)中产生相移长周期光纤光栅(LPFGs)的简单方法。通过光弹效应,用有凹槽的平板制作LPFGs;用螺丝控制2个凹槽平板之间的距离,可以得到不同的相移值,实现了相移值的连续可调。光栅的传输光谱可以通过所加外力实现调谐,谐振峰强度的可调谐范围达到了16dB。该方法对于光栅光谱的调谐有很大的灵活性,可应用于掺Er光纤放大器(EDFA)的增益平坦。 相似文献
3.
Synthesis of long-period fiber gratings with the inverted erbium gain spectrum using the multiport lattice filter model 总被引:1,自引:0,他引:1
Jinho Bae Joohwan Chun Sang Bae Lee 《Lightwave Technology, Journal of》2004,22(8):1976-1986
This paper proposes an accurate modeling technique of concatenated long-period fiber gratings (LPFGs). The proposed technique is then applied to the synthesis of LPFGs for the erbium gain equalization using both the simulated annealing and the steepest descent minimization technique. A piecewise-uniform LPFG is theoretically synthesized according to the inverted gain spectrum of a commercially available erbium-doped fiber amplifier (EDFA) over the range of 1525-1570 nm. Sensitivity analysis of the designed structure is presented by Monte Carlo simulation with regard to the manufactured amplitude mask. To verify a synthesizing technique using the proposed modeling, the piecewise-uniform LPFGs for gain flattening of EDFA are fabricated and their spectra are also presented experimentally. 相似文献
4.
根据实际所测得的S波段光纤拉曼放大器的信号增益谱,通过对长周期光纤光栅具体参数的选定,由两个长周期光纤光栅级联滤波的组合,可以使增益图谱在50 nm(1485-1535 nm)带宽内,增益平坦度达到±0.6dB以内.由三个长周期光纤光栅级联滤波组合,可以使增益图谱在49 nm(1490-1539 nm)带宽内,增益平坦度达到0.5 dB, 55 nm(1485-1540 nm)带宽内,增益平坦度达到1 dB.这对扩大长周期光纤光栅增益平坦滤波器的运用范围,扩大单泵浦S波段光纤拉曼放大器的有效增益带宽有着积极的意义. 相似文献
5.
A temperature-insensitive erbium-doped fiber amplifier for terrestrial wavelength-division-multiplexing systems 总被引:1,自引:0,他引:1
H. Nakaji Y. Ishizawa M. Ohmura T. Shibata A. Inoue M. Shigematsu 《Photonics Technology Letters, IEEE》2003,15(11):1522-1524
We have evaluated a variation in the temperature dependence of an erbium-doped fiber gain spectrum by a pump wavelength in the 980-nm band for the first time. By optimizing both the pump wavelength in the 980-nm band and a temperature-sensitive gain flattening filter, the gain change of an erbium-doped fiber amplifier was successfully suppressed to 0.18 dB/sub pp/ in the temperature range between 0/spl deg/C and 65/spl deg/C and the wavelength range of 37.0 nm. 相似文献
6.
L波段掺铒光纤放大器的增益平坦滤波器设计 总被引:7,自引:2,他引:5
EDFA的增益平坦化是WDM系统中的重要问题.用成本低、插损小的光纤光栅实现该功能是一项有吸引力的方案,采用剥层法设计了基于啁啾光栅的增益平坦滤波器。基于时间因果律的剥层算法将光纤光栅看成一个分离的模型,由一系列长度为△的复反射器所组成,每个反射器的后端耦合系数都可由它的前端耦合系数递归地求出,从而能快速、精确地反演出光栅的耦合系数函数。啁啾光栅的目标反射谱由理想的增益平坦滤波器透射谱获得,利用与反射谱群时延有关的常数α可控制光栅的长度,α取值为0.0024cm。时,对应的光栅长度为3.5cm。用剥层法反演出耦合系数函数后,又通过解Riccati方程模拟了合成光栅的透射谱。数值模拟结果显示理想透射谱与合成光栅透射谱之间的峰峰值误差小于0.1dB.并且在工作带宽范围内,透射谱群时延的变化量小于0.6ps,表明该滤波器对系统没有额外的色散影响。 相似文献
7.
Gain-flattening filter using long-period fiber gratings 总被引:4,自引:0,他引:4
We propose a novel structure for a gain-flattening filter, in which a conventional long-period fiber grating (LPFG) and a phase-shifted LPFG are written closely. The transmission characteristics are investigated in the case of a closely arranged configuration. For the fabrication of a phase-shifted LPFG, a UV-trimming method to control the amount of the phase shift is examined theoretically and experimentally. Finally, a 67-mm-long LPFG gain-flattening filter designed for an erbium-doped fiber amplifier is fabricated and the measured spectrum is shown 相似文献
8.
An innovative long-period fiber grating (LPG) synthesis method based on the stochastic evolutionary programming (EP) algorithms is demonstrated to be effective for designing optimal LPG filters. Synthesis of a single-stage LPG filter for the entire C-band erbium-doped fiber amplifier (EDFA) gain flattening is used as an example to show the feasibility and the effectiveness of the proposed algorithm. To the best of our knowledge, this is the first demonstration that good EDFA gain flattening for the entire band can be achieved with a single-stage LPG filter that is properly designed 相似文献
9.
《Photonics Technology Letters, IEEE》2008,20(17):1503-1505
10.
We propose a flexible method for flattening the gain profile of an erbium-doped fiber amplifier (EDFA). The method is based on a high-birefringence fiber loop mirror (HiBi-FLM), which contains a number of high-birefringence fiber sections and polarization controllers. We show that, by setting the polarization controllers properly, the reflection spectrum of the loop mirror can be adjusted to compensate for the variations in the gain profile of the EDFA. The method is demonstrated experimentally by using a single-section HiBi-FLM and a two-section HiBi-FLM, respectively, With a two-section HiBi-FLM, we are able to flatten the gain profile of an EDFA to within ±0.9 dB over a bandwidth of 33 nm at the center wavelength of 1543 nm, under different operating conditions of the EDFA 相似文献
11.
In this paper, we propose a novel method for controlling the gain spectrum of a thulium-doped fiber amplifier (TDFA) in the S-band. The conventional gain spectrum control method used for a silica erbium-doped fiber amplifier (EDFA) cannot be applied to TDFAs because of the complicated fluctuation of the TDFA gain spectrum. Our proposed method controls the gain spectrum by a combination of gain clamping and pump power adjustment. The algorithm for the method is as simple as that for the conventional EDFA gain spectrum control method. Furthermore, we describe a function for correcting the gain excursion generated by the incorporation of amplified spontaneous emission (ASE) at a signal monitoring photodiode (PD). We achieved a gain excursion of 0.35 dB against a total input signal power of 32 to 2 dBm. 相似文献
12.
P. Poopalan H. Haoken N. Tamchek S.W. Harun T. Subramaniam H.B. Ahmad 《Photonics Technology Letters, IEEE》2004,16(12):2604-2606
An erbium-doped (Er-doped) fiber amplifier operating in the C-band is gain clamped, at about 26 dB with noise figures below 6 dB by multiple fiber Bragg gratings. These gratings are placed at the amplifier output with center wavelengths in between communication channels so that unwanted amplified spontaneous emission is removed but put to good use. A 0.5-dB gain compression point at -15 dBm of input signal powers for two simultaneous signal channels is also demonstrated. 相似文献
13.
为了研究不同增益光纤长度下1555nm高功率光纤放大器的输出功率,采用两级混合结构的方法,用掺铒光纤放大器和双包层铒镱共掺光纤放大器分别作为1级预放大器和2级主放大器。掺铒光纤放大器对信号光进行预放大,并提高放大器的信噪比;双包层铒镱共掺光纤放大器为主放大器,其双包层结构可以把更多的多模抽运光耦合进系统。对铒镱共掺光纤的最佳长度做了理论分析和实验验证,在信号光功率为10mW、掺铒光纤放大器的抽运功率为318.58mW、双包层铒镱共掺光纤放大器的抽运功率为11.71W、增益光纤长度为14m时,输出功率取得了2.11W的实验数据。在分析输出信号光谱时发现,L波段附近有放大自发辐射谱出现,这是选择的增益光纤过长导致的。结果表明,在光功率和信号光功率一定时,光纤放大器有一个最佳的光纤长度。这一结果对研究光纤放大器的高功率输出是有帮助的。 相似文献
14.
A gain clamped long wavelength band erbium-doped fibre amplifier (L-band EDFA) based on a ring laser cavity is demonstrated using a fibre Bragg grating (FBG) at the output end of the amplifier. This new design provides a good gain clamping as well as a gain flattening. The gain is clamped at 16.9 dB with gain variation of less than 0.1 dB from input signal power of -40 to -18 dBm by setting the VOA=5 dB. Also, the amplifier has the flattest gain spectrum at VOA=5. The gain variation is less than 1.0 dB within the wavelength range from 1570 to 1600 nm. This gain clamped amplifier also can support a 12 channel WDM system. 相似文献
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16.
Step-changed long-period fiber gratings 总被引:2,自引:0,他引:2
Bai-Ou Guan A-Ping Zhang Hwa-Yaw Tam Chan H.L.W. Chung-Loong Choy Xiao-Ming Tao Demokan M.S. 《Photonics Technology Letters, IEEE》2002,14(5):657-659
The spectral characteristics of a new type of long-period grating (LPG) structure, step-changed LPG, are investigated theoretically and experimentally. It is shown that the spectral profile of such gratings can be tailored by adjusting the step parameters. A good agreement between simulated results and measured spectra is obtained. This type of LPG has potential applications in gain flattening of erbium-doped fiber amplifiers 相似文献
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We report new methods to inherently increase the flatness and bandwidth of erbium-doped silica fiber amplifiers from three perspectives: fiber design, pump-signal WDM coupler optimization, and amplifier structure. First, to achieve inherent control of the gain spectrum, a new type of composite fiber structure with an Er-doped core and a Sm-doped cladding ring is proposed and experimentally demonstrated. Interaction of the optical field with the Sm-doped cladding to produce evanescent wave filtering is modeled, which provides an in-line control of gain fluctuation in the erbium-doped flier amplifier (EDFA) C band, 1530-1560 nm. Second, the effect of the spectral characteristics of WDM couplers over the L band of an EDFA is explored. A fused taper fiber coupler for a 1480-nm pump is optimized for signals in the wavelength range of 1570-1610 nm by measuring the small-signal gain, gain tilt, and noise figure in an L-band EDFA. Finally, a new all-fiber structure for a wide-band EDFA, where the L and C bands were coupled serially, is demonstrated with optimized pump-signal couplers. Further optimization of the new composite fiber structure and the transient effects in the serially coupled EDFAs are also discussed 相似文献