High Resolution and High Sensitivity Laser Spectroscopy Using Non-Classical Light

使用非经典光的高分辨率和高灵敏度激光光谱

基本信息

批准号：
04452057
负责人：
YABUZAKI Tsutomu
金额：
$ 5.06万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

We have developed new methods of laser spectroscopy with high resolution and high sensitivity, the principles of which are considerably different from any other methods developed so far. In present methods, the characteristics of a free-running diode laser is used, i.e.very stable output power (amplitude) and large frequency (phase) noise causing the broadening of the spectral line. The phenomena used are based on the nonlinear interaction of atoms with such a laser field. It was found that such a laser field has more degree of freedom than a monochromatic laser field, so that it carries more information of atoms and molecules to be studied. The first method proposed and studied can be realized by a simple system, where a diode laser beam is applied to the sample and the temporal variation of the transmitted light intensity is detected. Frequency-analyzing the detected intensity fluctuation, we have found that the power spectrum includes simultaneously high resolution atomic spectra, such as the Zeeman and hyperfine spectra in both the ground and excited states, which are in a very wide frequency range from 100 kHz to more than 1 GHz. The second type proposed here is the isotope-selective spectroscopy, which enables us to observe the absorption spectra of a particular isotope from the mixed gaseous sample. The isotope selection is made by detecting a Zeeman frequency component of a particular isotope, as the laser frequency is scanned through the absorption lines of of various isotopes. Above methods of laser spectroscopy is useful particularly for the atoms in a particular circumstances. As such atoms, we have made the first studies on the neutral atoms in a superfluid helium, and also on the gaseous atoms existing in the vicinity of the surface of solids.

我们已经开发了具有高分辨率和高灵敏度的激光光谱方法的新方法，其原理与迄今为止开发的任何其他方法都大不相同。在目前的方法中，使用自由运行的二极管激光器的特性，即，稳定的输出功率（振幅）和较大的频率（相）噪声，导致光谱线的扩大。所使用的现象基于原子与这种激光场的非线性相互作用。发现这种激光场比单色激光场具有更大的自由度，因此它具有更多的原子和分子信息。提出和研究的第一种方法可以通过简单的系统实现，其中将二极管激光束应用于样品，并检测到发射光强度的时间变化。频率分析了检测到的强度波动，我们发现功率谱同时包括高分辨率原子光谱，例如在地面和激发态下的Zeeman和Hyperfine光谱，它们的频率范围从100 kHz到非常宽，从100 kHz到1 GHz。这里提出的第二种类型是同位素选择光谱法，这使我们能够从混合气体样品中观察特定同位素的吸收光谱。同位素选择是通过检测特定同位素的Zeeman频率分量来进行的，因为激光频率通过各种同位素的吸收线扫描。在特定情况下，以上激光光谱法对原子特别有用。这样，我们已经对超流体氦中的中性原子以及在固体表面附近存在的气态原子进行了首次研究。