Ultra-high laser frequency stabilization using spectral holes in a cryogenically cooled crystal as a frequency reference

使用低温冷却晶体中的光谱孔作为频率参考实现超高激光频率稳定

• 批准号: 215187986
• 负责人: Professor Stephan Schiller, Ph.D.
• 金额: --
• 依托单位: Institut für Experimentalphysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/215187986?language=en
• 关键词: Ultra; laser; frequency; stabilization; using

Laser sources with ultra-high frequency stability are of fundamental importance for precision atomic and molecular spectroscopy, time and frequency metrology, as well as fundamental physics, such as tests of Lorentz Invariance. The currently best method is servo-stabilization of the laser frequency to a mode of a ultra-low-loss optical cavity. This yielded relative instabilities of a few parts in 1016. However, even the best optical cavities are limited in principle by thermal noise and vibration sensitivity, and these are serious difficulties on the way to even higher performance. In this work, we will pursue an alternative approach for realizing ultra stable optical frequencies, based on a crystalline material doped with rare earth ions. Appealing features of a solid-state frequency reference are compactness (size ~1 cm3), ease of handling, relative immunity to environmental variations (magnetic field, temperature, acceleration), very narrow homogeneous linewidths (0.1 – 100 kHz) at temperatures below 5 K. A particular type of spectroscopy, spectral hole burning (SHB), is used to overcome the limitations imposed by inhomogeneous broadening of the optical transitions in solids (0.1 - 10 GHz). While this approach has been investigated for a long time, only very recently the applicants’ group and a group at NIST (USA) have independently shown that the optical transitions in the Europium-doped Yttrium orthosilicate crystal (Eu3+:Y2SiO5) at 580 nm do, in fact, have the potential for ultra-high frequency stabilization both on short and on long time scales. The fundamental stability limits of this approach are different from those of a reference cavity and therefore have the potential to surpass even the highest performance cavities on both short and long time scales. Therefore, we propose to fully develop this approach with the goal of demonstrating a performance better than state-of-the art optical cavities both on short times and on long time scales (goal 1×10-16 instability on time scales between 1 and 10 s, 1×10-15 for 100 -104 s). If this is achieved, the approach could become (in combination with a femtosecond frequency comb) an alternative to the widely used Hydrogen maser. The use of cryogenics is not in itself a contradiction to simplicity and reliability since modern cryogenic techniques offer compact, easy-to-use tabletop cryostats.

超高频率稳定性的激光源对于精确原子和分子光谱，时间和频率计量学以及基本物理学（例如洛伦兹不变性测试）至关重要。当前最好的方法是将激光频率伺服稳定为超低光腔的模式。这在1016年产生了几个部分的相对不稳定性。但是，即使是最佳的光腔也受到热噪声和振动敏感性的原理有限，并且在更高性能的途中，这是严重的困难。在这项工作中，我们将基于用稀土离子掺杂的结晶材料来实现一种实现超稳定光频率的替代方法。固态频率参考的有吸引力的特征是紧凑度（尺寸〜1 cm3），易于处理性，对环境变化的相对免疫学（磁场，温度，加速度），非常狭窄的均匀线宽（0.1 - 100 kHz）（0.1 - 100 kHz）在5 k以下的温度下。固体（0.1 - 10 GHz）中的光学转变。虽然这种方法已经进行了很长时间，但直到最近，申请人组和NIST的一个组独立地表明，在580 nm do的Europium掺杂YTTrium Orthosilicate晶体（EU3+：Y2SIO5）中，光学过渡在580 nm的DO中，实际上具有超高频率稳定的潜力，并且具有长时间的量表。这种方法的基本稳定性限制与参考腔的基本限制不同，因此在短时间和长时间尺度上都有可能冲浪最高的性能腔。因此，我们建议在短时间内和长时间尺度上表现出比最先进的光学腔（目标1×10-16的不稳定性在1到10 s之间的目标，1×10-15的目标1×10-16，100 -104 s的1×10-15）的目标是更好地证明性能。如果实现这一目标，则该方法可能会成为（与飞秒频率梳子组合），是广泛使用的氢maser的替代方法。低温药物本身并不与简单性和可靠性矛盾，因为现代的低温技术提​​供了紧凑，易于使用的桌面低温稳定。