Optical clocks based on stimulated emission radiation

• 来源期刊: 科学通报(英文版)
• 年，卷（期）: 2009,（3）
• 页码范围: 347
• 页数: 1页
• 语种: 英文
• DOI: 10.1007/s11434-009-0064-z

摘要

Atomic clocks operating at microwave region, are di-vided into two categories according to the mode of ope-ration, namely the passive mode, in which the standard frequency of a clock signal is locked on to a very narrow atomic spectral line such as in cesium beam and rubi-dium gas cell clocks, and the active mode, where the atomic ensemble itself can produce a high stable and accurate standard frequency signal such as hydrogen maser. The hydrogen maser has been the most stable atomic clock for nearly half a century, and has been applied in a variety of scientific research fields[1].