NOUREDDINE MELIKECHI Harnessing light to search for life on Mars and to save lives on Earth Interview with Glamour Fashion and Beauty
G.F.B: You started your research career at the University of Sussex in Great Britain. You have indeed been able, in a short time, to make an interesting discovery concerning the laws governing electromagnetic fields. Would you like to tell us a little more about this discovery? NM: Thank you for giving me the opportunity to share with your readers something about my professional journey which in my opinion, is worth doing only if it can help others. Explaining the discovery that you are referring to in lay terms is not easy, but I will try. As a young physics researcher, I had a strong interest in studying light but was not sure about the path to take. This interest stems from the fact that light is ubiquitous, can be studied from purely theoretically and/or experimentally, and inspires us to ask philosophical questions. I approached Professor Les Allen, a well-known researcher in quantum optics, the field that uses quantum physics to study phenomena involving light. Professor Allen accepted me in his research group and asked me to think about a phenomenon called two-photon absorption. This phenomenon was predicted in 1931 by Maria Goeppert-Mayer and demonstrated experimentally in the early 1960’s revolutionized spectroscopy and imaging. For her work, Maria Goeppert-Mayer became, in 1962, the second woman to receive the Nobel Prize in physics. Two-photon absorption is a process in which two 3
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fundamental particles of light, called photons, are absorbed almost simultaneously by matter. It was known that two-photon processes obey physics rules that are different than those for single-photon processes in which a single photon is absorbed by matter. The question was whether the two-photon absorption rules were complete or not. This is a fundamental question that, when addressed, enhances our understanding of how light interacts with matter. I discovered new rules that describe conditions for this process to be feasible and demonstrated that, in some two-photon absorption experiments, more information can be gained by carefully selecting the geometry of the various light fields involved. G.F.B: You arrived in the United States after spending two years in Algeria as part of your National Service. How did you get back into research? NM: Simply stated: by doing my best to take advantage of opportunities. Upon my arrival to the United States, I contacted few physicists which led me to speak with and be interviewed by Professor Edward Eyler who, at that time, was working on high precision atomic and molecular laser spectroscopy. An atom is made of a nucleus and electrons. These electrons have energy that varies from one atom to another. When two or more atoms “join” together, they form a molecule. For example, we talk about the hydrogen or the oxygen atom. These two atoms can be joined together to form 8
