SUCCESSIVE OSCILLATORY FIELDS AT RADIO TO OPTICAL FREQUENCIES

The methods of separated or successive oscillatory fields (often calle d Ramsey methods) are described for radio, microwave and optical coher ent radiation. The methods are initially described qualitatively. The quantitative theories of the methods are also given. For a two-level s ystem at radio frequencies exact expressions for the transition probab ility amplitudes for an arbitrary number of successive oscillatory reg ions can be found in terms of products of successive transformation ma trices. The expressions are greatly simplified if the oscillatory-fiel d regions are very short. If there are only two oscillatory-field regi ons the situation is similar to a Young's two-slit interference patter n except that the two paths are separated in spin space rather than no rmal space. Some results from more than two oscillatory regions are di scussed. The extensions of the methods and the theories to optical fre quencies are described. The advantages and disadvantages of the method s are given as are the many extensions of the method beyond the origin al concept.