光频标和光频测量研究的历史、现状和未来

History, present situation and future of optical frequency standard and optical frequency measurements

本文综合评述了光频标和光频测量研究的历史、现状和未来。在上世纪最后的30年间，光频标已达到10^-11-10^-13量级的准确度，使长度单位“米”进行了重新定义，实际上成为时间单位秒的“导出单位”。最近三年来，该领域的研究出现了重大突破。这是由于飞秒锁模激光技术与光频测量技术两者出人意外的结合，使微波频标与光频标之间建立了简易可行的联系，使光频标的准确度和实用性达到了前所未有的高度，成为计量学和物理学中一个新的亮点。它的进一步发展必将给计量学和物理学带来深远的影响。

The history, present situation and future of optical frequency standards and optical frequency measurements were presented. The uncertainty of optical frequency standards has come up to 10-11 ~ 10-14. In this way, length unit 'meter' became the derived unit of time unit 'second'. Recently, there was a great breakthrough in this field. The unexpected link of femtosecond mode-locked laser and optical frequency measurement technology make a simple relation between microwave standards and optical frequency standards. Frequency measurements get easier and more accurate because of this relation. This is a new brilliancy in metrology and physics.