SGER: Advanced Solid-State Laser with <20 Femtosecond PulseDuration (REU SUPPLEMENT)

在这项探索性研究的小额资助中，我们建议开发一种能够产生前所未有的短持续时间光脉冲的全固态激光系统。非线性锁模技术可用于从掺钛蓝宝石激光器产生飞秒持续时间的脉冲。该激光器获得的最小脉冲宽度的主要限制是激光腔内的光色散；也就是说，不同波长的光需要不同的时间来完成通过激光腔的往返。由于超短激光脉冲必须具有宽的光谱宽度，如果激光腔中存在大量色散，短脉冲将不会保持短。通过对色散的详细计算，我们发现了一些使该激光器色散最小的方法。我们已经制造出持续时间为25飞秒的脉冲——这是超快激光的记录。我们计划在这项工作的基础上进一步推进超快激光技术的发展。通过设计一种新的激光器，我们希望能够证明一种简单可靠的15-20 fs脉冲源。我们的工作有望扩大激光在研究电子材料和化学反应中的超快过程中的应用。

In this Small Grant for Exploratory Research, we propose to develop an all solid-state laser system capable of generating light pulses of unprecedented short duration. The technique of non-linear mode- locking can be used to generate femtosecond-duration pulses from a titanium-doped sapphire laser. The major limitation on the minimum pulse width obtainable from this laser is optical dispersion inside the laser cavity; i.e. different wavelengths of light take a varying time to complete a round-trip through the cavity of the laser. Since an ultrashort laser pulse must have a wide spectral width, a short pulse will not stay short if there is substantial dispersion in the laser cavity. By doing detailed calculations of dispersion, we have discovered a number of methods for minimizing it in this laser. We have already produced pulses of 25 femtoseconds duration-- a record for ultrafast lasers. We plan to expand upon this work to further advance the state-of-the-art in ultrafast laser technology. By designing a new laser, we expect to be able to demonstrate a simple and reliable source of 15-20 fs pulses. Our work promises to expand the utility of lasers for studying ultrafast processes in electronic materials and in chemical reactions.