Inaugural Hertha Sponer Presidential Lectureship
Margaret Murnane
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During the past decade, there has been a revolution in the field of ultrafast science. Visible light pulses of only a few optical cycles in duration can now be generated from a simple laser. By amplifying these light pulses to high powers, a visible laser beam can be converted into a laser-like, coherent, ultrafast, x-ray beam. Moreover, using computer algorithms, we can teach a laser to generate an optimally-shaped light pulse, that allows us to control how an atom or a molecule responds to light. This allows us, for example, to channel laser energy into a specific x-ray wavelength, or to selectively excite vibrations in molecules, as a first step to controlling chemical reactions with light. Applications in x-ray biological imaging will also be discussed.
Physics Department Colloquium
Margaret Murnane
University of Colorado
Harnessing Attosecond Science in the Quest for Coherent X-Rays
3:30 PM, November 7, 2007, Rm 128 Physics
To generate coherent x-ray beams, extreme nonlinear optical techniques have succeeded in upconverting visible laser light into the x-ray region of the spectrum. This ability has given us a new coherent light source that spans such a large region of the spectrum that we now access processes that occur on sub-femtosecond or attosecond (1 as=10^-18 s) time-scales. Equally intriguing is the fact that we have learned how to use femtosecond laser light to coherently manipulate electrons in atoms and molecules on their fundamental, attosecond timescales. The richness and complexity of attosecond science and technology is only just beginning to be uncovered. As I will discuss in this talk, attosecond science can capture the complex, interwoven dance of electrons in molecules and materials. Attosecond science also shows great promise for developing new ultrasensitive molecular imaging and spectroscopic techniques. Finally, attosecond science represents the most promising avenue to achieve what had seemed hopelessly impractical until now -- the generation of bright, coherent, hard x-ray beams using a tabletop-scale apparatus.
Coffee and cookies before the presentation at 3:15 pm, and refreshments after the presentation will both be served in Room 128.