1. Could you explain the significance of your article to the non-specialist?

We report the use of an unusual laser beam geometry that allows us to exploit special features of a 2-photon transition to "slice" the velocity distribution of a recoiling sphere of atoms to record images of this velocity distribution. This is otherwise difficult to do, particularly for fast fragments such as hydrogen atoms. The result is enhanced detection sensitivity and velocity resolution as well as greater convenience.

2. What has motivated you to conduct this work?

We sought a means to "slice" the H atom velocity distributions better and we have been thinking about novel "Doppler-free" approaches. This effort grew naturally out of our thinking along these lines. 

3. Where do you see this work developing in the future?

I believe there are many other possibilities to combine Doppler-free strategies, originally developed in the 1970s, with ion imaging and related methods now in widespread use. We have just begun.

4. Are there any particular challenges facing future research in this area?

One must be willing to invest time in exploring new approaches.