de Chatellus H Guillet, Pique J-P
Laboratoire de Spectrométrie Physique UMR 5588 CNRS-Université Joseph Fourier, Saint Martin d'Hères, France.
Opt Lett. 2009 Mar 15;34(6):755-7. doi: 10.1364/ol.34.000755.
The precision of interferometry is directly linked to the fringe spacing of the recorded interferogram. Whereas all interferometric devices show a fringe spacing equal to a wavelength of the laser light we present a novel scheme of a two-beam interferometer exhibiting a fringe spacing reduced by a factor of 2; the direct detection of the beat signal is replaced with the monitoring of the fluorescence of a twofold degenerate atomic system resonant with the laser. The lambda/2 fringe spacing in the fluorescence signal is demonstrated with a hot sodium vapor excited by a broadband laser tuned to the D1 line. In the saturation regime, the dark fringes are expected to be extremely narrow, leading to the possibility of nanoscale displacement measurements or atom localization.
干涉测量法的精度与所记录干涉图的条纹间距直接相关。尽管所有干涉测量设备显示的条纹间距都等于激光的波长，但我们提出了一种新型双光束干涉仪方案，其条纹间距减小了一半；直接检测拍频信号被监测与激光共振的双重简并原子系统的荧光所取代。通过调谐到D1线的宽带激光激发的热钠蒸汽，证明了荧光信号中的λ/2条纹间距。在饱和状态下，预计暗条纹会极其狭窄，从而有可能进行纳米级位移测量或原子定位。
