A simple fiber based light source for femtosecond laser spectroscopy

超快激光科学领域为探索科学动力学铺平了道路。主要目标是产生极短的光脉冲。自20世纪80年代以来，超快激光器从实验室专业产品走向商业产品。在20世纪90年代，光学参量放大器（OPA）随后发展，以创建可调谐脉冲。自2000年以来，非共线OPA （NOPA）可以产生非常短的脉冲。在所有这些光源中，有复杂的光束几何形状，需要成本，用户的努力，并导致偏差的脉冲质量。在这些无源光源中，典型的优点是转换效率、功率稳定性和带宽。本文提出一种利用飞秒放大器产生短脉冲的新技术方案。我们建议使用基于空心芯光纤（HCF）的方法，因为它的独特设计可以提高两个全新指标的性能：相位噪声和空间模式。我们基于光纤的方法具有与NOPA相似的性能，尽管成本和复杂性更低。我们方法的关键是建立一条前进的道路，以改善两个全新的绩效指标。相位稳定性的提高提高了现代相干光谱学的性能。空间模式的改进将改善光谱学，但对显微镜来说可能是革命性的。在本提案中，我们将充分表征，优化并继续开发该技术，以扩大其对各种应用的适用性，重点是超快激光光谱用户。其结果将是一种适合商业化的新技术。

The field of Ultrafast Laser Science has paved the way for exploring the science dynamics. The main objective is the generation of extremely short pulses of light. Since the 1980s, ultrafast lasers went from lab specialties to commercial products. In the 1990s, the optical parametric amplifier (OPA) was subsequently developed in order to create tunable pulses. Since 2000, the non-collinear OPA (NOPA) become commercially available to generate very short pulses. In all these sources there are complex beam geometries that require cost, user effort, and result in deviations to pulse quality. In these passive light sources, the typical figures of merit are conversion efficiency, power stability, and perhaps bandwidth. Here, we propose a new technological solution towards generation of short pulses from a femtosecond amplifier. We propose use of a hollow core fiber (HCF) based approach due to its unique design resulting in improved performance in two totally new metrics: phase noise and spatial mode. Our fiber based approach has similar performance to a NOPA, albeit with lower cost and complexity. The key point in our approach is establishing of a path forward to improve two totally new metrics of performance. The improved phase stability gives rise to improvements for modern coherent spectroscopy. The improvements in spatial mode will improve spectroscopy, but are likely to be transformative for microscopy. In this proposal we will fully characterize, optimize, and continue to develop the technology to expand its suitability for a variety of applications, with emphasis on ultrafast laser spectroscopy users. The result will be a new technology suitable for commercialization.