Mid-infrared, wide-bandwidth, stable coherent optical sources generated by multi-material, nonlinear chalcogenide-glass fibers

目的：设计、制造和测试包含高度非线性硫系玻璃的多材料光纤，通过三阶和二阶非线性光学相互作用产生中红外（MIR）相干辐射。采用新纤维设计的纤维预制体将通过挤压和拉伸制成优化的纤维，以产生覆盖整个中红外光谱的超连续辐射。智力优势：拟进行的研究整合了工程和应用科学的几个领域，包括非线性光学、光纤和材料科学。该项目的成功取决于解决这些领域交叉的几个长期存在的问题（在同一纤维中结合多种广泛不同的材料，硫系玻璃纤维中的色散工程等），并将因此促进未来在MIR非线性光学和硫系玻璃纤维中的参数相互作用方面的研究。更广泛的影响：该项目将在一个独特的环境中，由研究生和本科生组成的团队进行跨学科研究。一旦成功，该项目将对MIR光谱和成像领域产生变革性影响。例如，它将允许光谱学家在传统的非相干（热）MIR光源无法提供的高亮度水平上追求高分辨率MIR光谱。MIR在分子光谱指纹识别的光谱学中尤为重要，高亮度相干宽光谱光纤光源的可用性将允许光谱成像的新模式，其中空间分辨率与光谱和时间辨别相结合（这将是有利的，例如，在拉曼显微镜中）。

Objective:We aim to design, fabricate, and test multi-material fibers that incorporate highly nonlinear chalcogenide glasses for generation of mid-infrared (MIR) coherent radiation via third-order and second-order nonlinear optical interactions. Fiber preforms that incorporate new fiber designs will be fabricated by extrusion and drawn into fibers optimized to produce supercontinuum radiation that covers the entire mid-infrared spectrum.Intellectual merit:The proposed research integrates several areas of engineering and applied science including nonlinear optics, optical fibers, and material science. The success of the project rests on the resolution of several long-standing problems at the intersection of these fields (incorporation of multiple widely diverse materials in the same fiber, dispersion engineering in chalcogenide glass fibers, amongst others) and will thus foster future research in MIR nonlinear optics and parametric interactions in chalcogenide glass fibers.Broader Impacts:The project will engender for inter-disciplinary research to be carried out with a team of graduate and undergraduate students in a unique setting. Upon success, this project will have a transformative effect on the field of MIR spectroscopy and imaging. It will allow spectroscopists, for example, to pursue high-resolution MIR spectroscopy at high brightness levels not afforded by traditional incoherent (thermal) MIR sources. The MIR is particularly important in spectroscopy for molecular spectral finger-printing, and the availability of a high-brightness coherent wide-spectrum fiber-based source will allow for new modalities of spectroscopic imaging where spatial resolution is combined with spectral and temporal discrimination (as would be advantageous, for example, in Raman microscopy).