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Developing the Next Generation of Spectroscopic Tools
Laser spectroscopy allows scientists to probe the dynamics and properties of the materials -- both biological and synthetic. As we develop new ways to probe these systems, we learn more about how to design and control the dynamics require to generate new functional materials.
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Nonlinear spectrosocpic methods probe dynamics on the timescale of femtoseconds -- millionths or a billionth of a second. Two dimensional electronic spectra allow us to directly inspect how excited states are coupled to one another, how they relax, and how they trade energy.
After many sleepless nights in the lab collecting data, we recently developed a new approach to acquiring 2D electronic spectra that utilizes spatiotemporal gradients indirect analogy to the quantum mechanics of Magnetic Resonance Imaging (MRI). This new tool allows us to probe systems 300x faster with 50x better signal to noise.
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The spectra that we acquire contain information about how states couple to one another as a function of time. The Fourier transform of coherent beating signals allows us to create 3D represenations of our data and directly extract parameters from the underlying Hamiltonian.
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Sample Publications
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A.F. Fidler, E. Harel, G.S. Engel, "Dissecting Hidden Couplings Using Fifth-Order Three-Dimensional Electronic Spectroscopy" J. Phys. Chem. Lett., 2010, 1 (19), pp 28762880 |
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E. Harel, P.D. Long, and G.S. Engel, “Single-shot Ultrabroadband Two-dimensional Electronic Spectroscopy of the Light-harvesting Complex LH2” Opt. Lett. 36:9 1665-1667 2011 |
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E. Harel, A.F. Fidler, G.S. Engel, "Real-time Mapping of Electronic Structure with Single-shot Two-dimensional Electronic Spectroscopy" PNAS, 107 16444-16447, 2010 |
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