CAREER: Fiber-based Optical Frequency Standards Characterized With Optical Frequency Combs

智力优势：基于超快激光器的稳定光学频率梳彻底改变了光学频率的测量。 这些梳，当稳定到世界上最好的微波和光学标准，已被用于许多优雅的调查基本常数。 此外，它们已被用于确定容易获得的波长标准的更实际的应用。 最终，每个人都可能在他或她的实验室或工厂中拥有基于梳状的光学频率合成器。 事实上，这项研究将有助于实现这一梦想。 便携式梳将需要低成本，便携式光学频率基准的许多应用。这些参考也需要校准目前在工业中使用的其他光学频率测量设备。PI建议开发基于中空低损耗光纤的新型气室，称为光子带隙（PBG）光纤。 PBG光纤电池将比其玻璃蒸汽电池对应部件更加坚固。 此外，在这些单元中可以观察到更窄的吸收特征，因为光可以被限制在高强度下，在这些光纤的芯中具有非常低的损耗，从而促进限制在其中的分子上的饱和吸收光谱。 更窄的线宽将导致更高的精度。 这些便携式光纤标准具有10 - 100 kHz的精度潜力。 通过稳定这些参考梳，我们可能会创造出比石英振荡器更稳定的无线电频率。更广泛的影响：电信行业目前依赖于具有约1 GHz宽吸收特性的蒸汽电池来校准波长测量设备。 本文提出的PBG纤维细胞的鲁棒性将增加这些分子参比品可以包括的设备范围。 此外，这些标准的更高精度将满足日益密集的波长信道封装所带来的日益增长的需求。 稳定到这些参考的梳可以被结合在激光雷达中，或者作为稳定的便携式射频源。 教育方面的影响也将是巨大的。 两名研究生和一名本科生将受雇于这项研究。 PI将把本研究的各个方面纳入入门级，高级本科和研究生水平的教学中。 PI已经参与了堪萨斯州立大学针对高中和六年级女生的外展项目，并正在努力招募一名有才华的少数民族大学新生进入实验室。

Intellectual Merit:Stable optical frequency combs based on ultrafast lasers have revolutionized measurements of optical frequencies. These combs, when stabilized to the world's best microwave and optical standards, have been used for many elegant investigations of fundamental constants. In addition, they have been employed for the more practical applications of determining readily accessible wavelength standards. Ultimately, everyone may have a comb-based optical frequency synthesizer in his or her laboratory or factory. Indeed, this research will contribute to making that dream a reality. Portable combs will require low-cost, portable optical frequency references for many applications. Such references are also needed to calibrate other optical frequency measurement devices currently employed in industry.The PI proposes to develop novel gas cells based on a hollow, low loss optical fiber, called photonic bandgap (PBG) fiber. PBG fiber cells will be much more robust than their glass vapor cell counter-parts. In addition, narrower absorption features can be observed in these cells, because light can be confined at high intensities with very low losses in the core of these fibers, facilitating saturated absorption spectroscopy on the molecules confined within. Narrower line widths will lead to higher accuracy. These portable, fiber-based standards have the potential for accuracies of 10 - 100 kHz. By stabilizing a comb to these references, we may potentially create radio frequencies more stable than those of a quartz oscillator.Broader Impacts:The telecommunications industry currently relies on vapor cells with absorption features ~ 1 GHz wide to calibrate wavelength measuring devices. The robust nature of the PBG fiber cells proposed here will increase the range of devices into which these molecular references can be included. Furthermore, the higher accuracy of these standards will fill the increasing demands brought on by increasingly dense wavelength channel packing. Combs stabilized to these references may be incorporated in lidar, or as a stable, portable rf source. The educational impacts will also be significant. Two graduate students and an undergraduate would be employed in the research. The PI will incorporate aspects of this research in teaching at the introductory, advanced undergraduate, and graduate levels. The PI has already become involved in outreach programs at Kansas State University that target high school and 6th grade girls, and is working to recruit a talented minority college freshmen to the lab.