Ultra-High-Capacity Optical Communications and Networking: Advanced Raman Gain for Next Generation Networks

该提案是根据NSF 01-65“超高容量光通信和网络”招标提交的。在短距离和长距离网络中对通信信道不断增长的需求要求在硅基光纤的最小损耗附近扩大可用频谱区域。1400nm处“水”吸收峰的急剧减少打开了1270到1650nm的可用通信窗口，对应于约50thz。如此大的带宽排除了现有的掺铒光纤和半导体激光器，使拉曼增益成为主要的放大机制。然而，二氧化硅光纤中的拉曼带宽只有10太赫兹，并且二氧化硅玻璃中的增益系数很小。作为解决方案，pi建议研究利用拉曼增益放大本地网络、中距离网络和长途光纤传输信号的新材料。新的拉曼增益介质将以体积和光纤两种形式考虑，第一种用于局域网和专门应用，第二种用于更远距离传输。新的玻璃、分子和聚合物材料将被制造出来，并通过自发拉曼散射、拉曼增益测量来表征。以及光纤网络环境下拉曼增益材料的评价。其中的一部分将被制成光纤，并在网络场景中评估拉曼增益。PIs建议探索新的氧化物和非氧化物玻璃类别，以优化结构-性能关系，为拉曼增益提供最佳性能。这些玻璃将包括含不同砷、硫和硒含量的硫系玻璃，以及重金属卤化物玻璃，如“TeX”玻璃。感兴趣的氧化物玻璃是磷酸盐、重金属氧化物和硼磷酸盐，它们表现出光谱宽的拉曼带。各种有机物种将被检查，主要是聚合物形式。有机介质中功能基团的多样性可以覆盖完全所需的50太赫兹带宽，甚至更多，以获得拉曼增益。聚合物混合物和复合材料将包含专门设计的分子，覆盖该光谱范围，并测量其拉曼信号强度。感兴趣的家族将包括聚噻吩和相关聚合物，以前已经显示出强烈的拉曼散射。还将研究具有高热稳定性和光化学稳定性的荧光基团家族。无机和有机成分可以以几乎任何比例组合，以获得混合溶胶-凝胶纳米复合材料，其组成，加工特性和性能极其通用。因此，通过明智地选择有机成分，可以实现特定的光学特性，如延长拉曼带宽和增益系数。

0123484 StegemanThis proposal was submitted in response to the solicitation NSF 01-65 on "Ultra-High Capacity Optical Communications and Networking." The continuously growing demand for communications channels in short and long distance networks necessitates an expansion of the available spectral region near the loss minimum of silica-based fibers. Dramatic reduction of the "water" absorption peak at 1400 nm opened up the available communications window from 1270 to 1650 nm, corresponding to about 50 THz. Such a large bandwidth rules out existing erbium doped fibers and semiconductor lasers leaving Raman gain as the prime amplification mechanism. However, the Raman bandwidth in silica fibers is only 10 THz, and gain coefficients in silica glass are small. As a solution the PIs propose to investigate new materials for signal amplification by Raman gain for local networks, intermediate distance networks and long-haul fiber transmission. New Raman gain media will be considered in both bulk and fiber form, the first for local area networks and specialized applications, and the second for longer distance transmission.New glass, molecular and polymeric materials will be fabricated, and characterized by spontaneous Raman scattering, Raman gain measurements. and the evaluation of the Raman gain materials in a fiber network environment. A selection of those will be fabricated into fibers and the Raman gain evaluated in network scenarios. The PIs propose to explore new classes of oxide and non-oxide glasses to optimize the structure-property relations that give the best properties for Raman gain. These will include chalcogenide glasses with varying As, S, and Se content, and heavy metal halides such as the "TeX" glasses. Oxide glasses of interest are phosphates, heavy metal oxides, and borophosphates which exhibit spectrally broad Raman bands. A variety of organic species will be examined, mostly in polymer form. The diversity of functional groups in organic media can cover the fully desired 50 THz bandwidth, and more, for Raman gain. Polymer blends and composites will be prepared that contain specifically designed molecules that cover this spectral range and their Raman signal strength measured. Families of interest will include polythiophenes and related polymers that have previously shown strong Raman scattering. Also investigated will be the fluorenyl family of chromophores which possess high thermal and photochemical stability. Inorganic and organic components can be combined in virtually any ratio to obtain hybrid sol-gel nano-composites extremely versatile in their composition, processing characteristics, and properties. Thus through judicious selection of the organic component, particular optical properties can be realized such as extended Raman bandwidth and gain coefficient.