Numerical comparison on the characteristics between backward and bi-directionally pumped DFRAs in hybrid Raman/EDFAs

The characteristics of broadband backward and bi-directionally pumped distributed fiber Raman amplifiers (DFRAs) in hybrid Raman/erbium-doped fiber amplifiers (HFAs) configuration are compared numerically based on noise-nonlinear figure (NNF) when standard single mode fiber (SMF) and non-zero dispersionshifted fiber (NZDSF) are considered. It is found that achievable NNF in optimized bi-directionally pumped HFAs is about 1.2 dB (or 1.7 dB) higher than that in backward pumped HFAs for SMF (or NZDSF), and better characteristics can be achieved by using NZDSF rather than SMF for long haul transmission.     

Experimental demonstration of output power spectrum clamping for multi-channel backward-pumped distributed fiber Raman amplifiers

Output power spectrum clamping over C+L band (84 channels) is demonstrated experimentally on a standard 100-km single mode backward-pumped distributed fiber Raman amplifier (B-DFRA). The clamping is realized by pump adjustment based on a simple linear relation of individual pump power versus on-off gain level and gain tilt in its spectrum. The average clamping error over all channels are less than 0.32 dB within the experimental range.     

Reduction of Refractive Index Contrast Threshold for Photonic Band-Gap in Square Lattices

The threshold of refractive index contrast （RIG） to open a photonic band gap can be reduced by symmetry breaking. For the case of square lattice composed by dielectric cylinders, the absolute band gap is demonstrated by inserting small rods in the centre of the lattices, and the threshold RIC is reduced to 3.8. As for the square lattices composed by air holes in dielectric, the minimal RIC required for an absolute band gap decreases to 2.20.     

大芯区的单模光子晶体光纤

采用毛细玻璃管拼接并拉丝的方法试制成功光子晶体光纤样品 ,它由石英纤芯和周围呈六角形分布的两圈气孔组成 ,气孔直径 4 μm ,间距 17μm ,芯区直径 30 μm。理论模拟和光学实验均证实此光纤在 6 32 8nm以上的波长范围内为单模光纤     

与单模光纤高效耦合的超辐射二极管优化设计

为了提高脊波导结构的超辐射二极管(SLD)与单模光纤的耦合功率,研究了有源区与脊之间的残留层和上光限制层的厚度对SLD输出功率和近场光斑的影响.考虑了注入载流子横向分布的不均匀,较准确地计算了模式增益.结果表明,通过对残留层和上光限制层厚度的优化,可以有效提高SLD与单模光纤的耦合功率.     

掺铒光纤放大器多信道增益谱迭代测试法

针对多信道放大时掺铒光纤放大器（ＥＤＦＡ）的增益谱随饱和深度而变化的现象，本文介绍了ＥＤＦＡ增益谱在等效饱和条件下的双波长和宽谱光源迭代测试法及等效饱和信号功率的计算公式．使用这种方法只需少数几次迭代即可准确测出当ＥＤＦＡ应用于波分复用系统时各信道的实际增益，实验测得结果的误差不大于０１５ｄＢ．     

与单模光纤高效耦合的超辐射二极管优化设计

为了提高脊波导结构的超辐射二极管(SLD)与单模光纤的耦合功率,研究了有源区与脊之间的残留层和上光限制层的厚度对SLD输出功率和近场光斑的影响.考虑了注入载流子横向分布的不均匀,较准确地计算了模式增益.结果表明,通过对残留层和上光限制层厚度的优化,可以有效提高SLD与单模光纤的耦合功率.     

Multiwavelength Raman fiber ring laser with the spectrum profile broadened by parametric four wave mixing in highly nonlinear dispersion-shifted fibers

Stable continuous wave (CW) multiwavelength fiber lasers have been investigated extensively in recent years due to their wide applications in wavelength division multiplexing (WDM) optical communication systems, fiber sensing, fiber-optical components testing, and so on[1]. The initial attention was focused on the rare- earth-doped fiber lasers, especially on erbium-doped fiber (EDF) lasers (EDFLs), where special means are required for stable multiwavelength operation due to the relatively…     

Photonic crystal waveguides and their applications

Two-dimensional （2D） slab photonic crystal waveguides （PCWGs） on silicon-on-insulator （SOI） wafer were designed and fabricated. Full photonic band gap, band gap guided mode, and index guided mode were observed by measuring the transmission spectra. Mini-stop-bands in the PCWG were simulated with different structure parameters. Coupling characteristics of PCWG were investigated theoretically considering the imperfections during the fabrication process. It was found that suppressing power reservation effect can realize both short coupling length and high coupling efficiency.     

1480nmLD泵浦掺铒光纤放大器的增益带宽特性的研究

采用国产１４８０ｎｍＬＤ及优化的掺铒光纤，研制成光纤增益达３２ｄＢ、最大输出功率为１０ｄＢｍ、带宽大于２５ｎｍ的掺铒光纤放大器模块（其纤入纤出净增益为２７ｄＢ、输出功率为７ｄＢｍ）。讨论了放大器的增益、带宽特性及ＡＳＥ对放大器测量的影响。